85 MATE CHOICE AND FEMALE CONDITION IN PHOTINUS IGNITUS FIREFLY FLASH RESPONSIVENESS
*Christopher K. Cratsley & Sara M. Lewis
Department of Biology, Tufts University, Medford, MA 02155 (ccratsle@emerald.tufts.edu)
Female Photinus fireflies respond to the bioluminescent courtship flashes of conspecific males with their own bioluminescent flash. Males use these responses to find potential mates, often engaging in lengthy courtship dialogs of male flashes and female responses before locating the female. Failure by a female to respond consistently to a male's courtship flashes may indicate either that the female is not ready to mate, or that she is not responsive to a particular male's flash characteristics. In order to explore these two possibilities we measured the responsiveness of field captured, female Photinus ignitus fireflies to computer-generated artificial flashes from light emitting diodes representing the range of male flash durations observed in the field (55 to 87 msec). Groups of females were also mated or offered protein supplement prior to testing flash responsiveness. Field captured females responded preferentially to longer duration flashes. However, overall female responsiveness declined significantly when females were either fed or previously mated. Therefore variation in female responsiveness may represent both female choice and variation in female mating and nutritional status. (Session 16: Sexual selection III; Mon. 2:30-2:50pm; Olin)
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161 ENVIRONMENTAL HETEROGENIETY & BROOD SIZE IN A BURYING BEETLE
J. C. Creighton
Department of Zoology, Brigham Young University, Provo, UT 84602 (curtis_creighton@byu.edu)
How many young to raise is a fundamental question of life history evolution. In the burying beetle Nicrophorus orbicollis, parents actively regulate brood size through filial cannibalism, which results in a positive correlation between size of the brood and size of the vertebrate carcass used as a food resource for the young. Adult body size is important in competition for carcasses. However, the advantage of large size varies with local population density of burying beetles. I used a simple optimality model to generate predictions about how beetles density should affect the number of offspring raised by parents. First, average adult body size should vary positively with population density. Second, brood size on a given-sized carcass should be larger (thus produce more but smaller young) in sparse populations than in dense populations. Third, females should respond adaptively to changes in local population density. All three predictions were supported using a combination of field and laboratory experiments. These results: 1) show that clutch size is a phenotypically plastic trait, and 2) support the idea that clutch size decisions are an intergenerational phenomenon that varies with the anticipated competitive environment of the offspring. (Session 32: Evolution and SS II; Tues. 4:10-4:30pm; Olin)
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28 DOMINANCE, MOLT AND CONSTRAINTS ON MIGRATION
*Daniel A. Cristol & Karen M. Johnson
Department of Biology, College of William & Mary, Williamsburg, VA 23187 (dacris@facstaff.wm.edu)
This study examined whether molt is a constraint on when birds can depart wintering grounds to migrate to breeding areas. Many birds undergo a partial molt before migrating north in spring. White-throated sparrows replace some body feathers and all feathers on their elaborately-patterned heads. We predicted that dominant white-throated sparrows, which have priority of access to food and other resources, would be in better physiological condition in early spring, so could molt earlier and therefore depart earlier to acquire desirable breeding territories. Sparrows were captured to assess dominance status, then released and monitored throughout the winter until they departed in spring. Dominant birds molted earlier and departed earlier, as predicted. This suggests that molt date is determined by physiological condition and is a constraint on timing of migration. A bird competitive ability in winter, or the quality of the habitat it can occupy during the non-breeding season, may have cross-seasonal effects on the date that it can return to breeding areas, and consequently its competitiveness for prime breeding territories. A follow-up study tested the relationship between social status and condition, and the role of experimentally-induced molt as a constraint on departure date. (Session 6: Dispersal & Migration; Sun. 4:30pm; Rooke)
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P41 BEHAVIORAL INTERACTIONS BETWEEN INTRAGUILD PREDATORS
Patrick W. Crumrine
Center for Ecology, Evolution and Behavior, University of Kentucky, Lexington Kentucky 40506 (patrick@darwin.ceeb.uky.edu)
Intraguild predation (IGP) and IGP risk/opportunity add important but understudied complexities to predator-prey interactions. Here I describe several possible ways two predators, larvae of the dragonflies Anax junius and Plathemis lydia interact when sharing a common prey species, Fathead Minnow hatchlings (Pimephales promelas). When these two predators prey in combination on P. promelas their effect is less than that predicted by a multiplicative risk model, which implies risk reduction for the prey. My findings indicate that the behavioral interaction between A. junius and P. lydia is asymmetric. Additionally the presence of P. lydia causes a diet shift in A. junius. This study provides insights into the conditions that result in risk reduction when prey species face multiple predators. (General Posters; Sun. eve; Terrace)
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P7 MATE CHOICE IN ELECTRIC FISH (SIZE DOES MATTER)
*Caroline C. Curtis & Philip K. Stoddard
Department of Biological Science, Florida International University, Miami, FL 33199 (CGCurt@aol.com)
Brachyhypopomus pinnicaudatus is a nocturnal, pulse type weakly electric fish from South America. Males are larger than females and emit a longer duration, higher amplitude electric organ discharge (EOD). Sexual dimorphism in electric communication signals is an excellent model for neurobiology and endocrinology, but nothing is known about the relevant behavior (e.g. mate choice). We conducted a series of unforced mate choice tests on gravid females in the lab. The choosing female was separated from her prospective choices by screens but could pass through a trap door to be with the other fish, a move taken as her display of preference. Females given a choice between a female and a male only chose the male if he was relatively large for a male. Females given a choice between large and small males chose larger males. Three correlated sexually dimorphic characters (body length, EOD duration, EOD amplitude) were larger for the chosen males. To dissociate these correlated male characters experimentally, we are testing females on electric playback stimuli. Equipment and supplies were provided by NIH/NIGMS-GM08205. (Founders Award poster; Sun. eve; Terrace)
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P42 INDIVIDUAL RECOGNITION IN DOMESTICATED QUAIL
*Brian Cusato & Melissa Burns
Department of Psychology, University of Texas at Austin, Austin, TX 78712 (cusato@mail.utexas.edu)
Riters and Balthazart (1998) recently suggested that male domesticated quail can discriminate between individual females based on differential sexual opportunity. Males preferred to remain near females with which they had previous sexual experience. We examined whether this discrimination was based on visual or behavioral characteristics. In Experiment 1, males were allowed to view a female (the conditioned stimulus or CS+) through a window immediately prior to a period of copulatory access to the same female (the unconditioned stimulus). The same males were also exposed to a different female with which they were not permitted to copulate (the CS-). Consistent with previous claims, males came to spend significantly more time in front of the window viewing the CS+ female than they did veiwing the CS- female. However, this may have been a response to female sexual anticipatory behaviors rather than individual female characteristics. When differential female sexual anticipation behaviors were unavailable (in Experiment 2), differential responding to individual females was not observed. These findings suggest that males identify sexual partners based on behavior of the female more so than individual characteristics. (General Posters; Sun. eve; Terrace)
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44 NO EVIDENCE FOR CONDITION DEPENDENCE IN A VARIABLE, CONSPICUOUS, AND SEXUALLY DIMORPHIC BREEDING PLUMAGE
James Dale
Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 (jd11@cornell.edu)
I tested the hypothesis that the colorful breeding plumage of red-billed queleas Quelea quelea is a condition dependent signal of phenotypic quality. Queleas are unusual birds because males molt into an extraordinarily variable breeding plumage. Within Zimbabwean populations, the heads and breasts of males varied from yellow to red and their facial mask patterns varied from white to black. Predictions based on the hypothesis that plumage color is a sexually selected quality indicator were not supported. First, plumage characters had bimodal distributions and co-varied independently of each other which would not be expected if these traits indicated quality. Second, plumage hue did not correlate with indices of phenotypic condition, reproductive success, or age. Third, plumage coloration was strongly heritable and is probably based on a few alleles at a few loci, rather than on the overall genetic (and hence phenotypic) quality of the individual. I conclude that quelea breeding plumage is not a condition dependent indicator. I propose an alternative hypothesis, that the plumage variation results from selection on males to be individually recognizable by their nest-neighbors. (Session 9: Allee Award session; Mon. 10:50am; Forum)
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189 CONCENTRATION-BASED CHEMOTROPOTACTIC ORIENTATION IN STARFISH
Jonathan Dale
Boston University Marine Program, Marine Biological Laboratory, Woods Hole, MA 02543 (jdale@bio.bu.edu)
Starfish are primarily chemosensory animals, but they lack familiar adaptations used by other animals for chemosensory orientation, such as bilaterally paired, specialized receptor organs, and they move at least an order of magnitude slower than most animals whose chemosensory orientation strategies have been studied. Three experimental approaches were used to study the starfish orientation strategy. Analysis of paths of orienting starfish indicates that orientation is based purely on chemical information (chemotaxis) and not flow information (rheotaxis). Observation of ray choice (changes in the behavioral anterior over the course of an orientation trial) in lesion experiments demonstrates that chemical information is compared between rays (chemotropotaxis), rather than between successive sampling positions (chemoklinotaxis). Recordings of odor concentrations in the odor plume show that, due to their low movement rates and position in the bottom boundary layer, starfish have access to mean local concentration information that is probably unavailable to faster moving animals, which may use other, fine-scale odor distribution cues instead. A model of this concentration-based chemotropotactic orientation strategy in a simulated plume is consistently successful at locating the odor source and behaves similarly to real starfish in terms of paths and ray choice, demonstrating the viability of the strategy and generating testable predictions about starfish behavior. (Session 38: Mechanisms IV; Weds. 2:10-2:30pm; Gallery)
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70 AN ASSOCIATION BETWEEN FORCED COPULATION ATTEMPT AND TESTOSTERONE LEVEL IN THE MALLARD, ANAS PLATYRHYNCHOS
Ellen S. Davis
Department of Zoology, University of Wisconsin, Madison, WI 53706 (esdavis@students.wisc.edu)
Testosterone levels in male birds appear to be positively associated with polygynous behaviour such as increased singing or the establishment of larger territories. Forced copulation, which is seen in a great variety of taxa, is thought to be a form of polygynous behaviour that serves to increase fitness, but nothing yet is known about the hormonal mechanisms involved. In this study, a positive association was found between testosterone level and forced copulation attempt in captive mallards, Anas platyrhynchos. Moreover, this association was found only during the spring breeding season, which is when forced copulation typically is observed. Further, neither testosterone level nor forced copulation attempt appeared to be associated with any other factor in this study such as pair status, corticosterone level or sampling time. These results are consistent with the relationship found between other forms of polygyny and testosterone level. (Session 13: Allee Award session; Mon. 2:30pm; Forum)
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201 EFFECTS OF HUMAN ACTIVITIES ON THE BEHAVIOR AND REPRODUCTION OF WILD PYGMY MARMOSETS
*A. Stella de la Torre
Department of Psychology, University of Wisconsin, Madison WI 53706 (sdelator@students.wisc.edu)
The habitat specialization of pygmy marmosets Cebuella pygmaea, on flooded forests along river banks, and the great importance of vocal communication and social behaviors in this cooperatively breeding species, allowed it to be used as bioindicator of habitat quality to evaluate the effects of tourism and human presence in Ecuadorian Amazonia. Six groups of marmosets were observed in sites that differed in the number of tourists and use of motor boats. Reductions in social play and in the use of the lower stratum of the forests were significantly correlated with tourism pressure. Capture by local people of marmosets from two of the studied groups, led to significant reductions in observability, vocalization rates and use of the lower strata in these groups. All these behavioral changes appeared to be an effort of the marmosets to avoid contact with humans and were possibly related to differences in the reproductive performance of the groups. (Research supported by the National Geographic Grant 5806-96 and additional support from the Milwaukee Zoological Society)(Session 40: Parental Care III; Weds. 2:50-3:10pm; Olin)
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141 WHAT DRIVES THE EXAGGERATION OF MALE SECONDARY SEXUAL TRAITS IN GREAT FRIGATEBIRDS?
*Donald C. Dearborn, Angela D. Anders & Patricia G. Parker
Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1735 Neil Avenue, Columbus, OH 43210 (dearborn.4@osu.edu)
Sexual selection predicts that exaggerated sexual traits in one sex should correlate with disproportionate parental effort by the other. Frigatebirds exhibit balanced parental care (a highly-conserved ancestral trait) in conjunction with strong sexual dimorphism (a derived trait not found in other seabirds). We are testing two hypotheses for the presence of sexual dimorphism in great frigatebirds (Fregata minor). The evolution of exaggerated male sexual traits could be driven by a male-biased operational sex ratio (OSR) or by the opportunity for extra-pair fertilizations (EPFs). In 1998, the OSR at our study site was strongly male-biased, but the frequency of EPFs was very low (3%). Three mechanisms could underlie a skewed OSR: a skewed nestling sex ratio, differential male and female mortality, or a difference in the frequency with which males and females attempt to breed. Preliminary results suggest that males attempt to breed more frequently than females. A more definitive test of this hypothesis is underway. (Session 28: Evolution and SS I; Tues. 2:10-2:30pm; Olin)
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160 JEAN-JACQUES ROUSSEAU: BEHAVIORAL ECOLOGIST
Donald A. Dewsbury
Department of Psychology, University of Florida, Gainesville, FL 32611 (dewsbury@psych.ufl.edu)
In 1755 Jean-Jacques Rousseau (1712-1778) published an essay, A Discourse on Inequality, in which, in an effort to understand the origins of inequality among humans, he speculated on the nature of early human life and the evolution of society. I find in the logic he used in his deliberations to provide anticipations of many of the ideas that have become pivotal in contemporary behavioral ecology. These include evolution, natural selection, adaptation, selection at the level of the individual, resource defense, kin selection, sexual selection, and others. Obviously, these nascent ideas were not developed in the manner later brought forth by Darwin and his followers. However, I believe that Rousseau merits recognition for his foreshadowing of ideas that would later become prominent. (Session 32: Evolution and SS II; Tues. 3:50-4:10pm; Olin)
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26 MIGRATION ON A DRY CONTINENT: MIGRATION FREQUENCIES IN AUSTRALIAN BUTTERFLY FAUNAS
*H. Dingle1, W. A. Rochester1 & M. P. Zalucki2
1Department of Entomology, UC Davis, Davis CA 95616; 2Department of Entommology, University of Queensland, Brisbane 4072 Australia (rdhdingle@ucdavis.edu)
On a continental scale latitude explained none of the variance in migration frequency among Australian butterflies. This is in marked contrast to temperate zone birds. Only in eastern Australia, where rainfall regimes are similar to temperate Europe, North and South America, does latitude explain variance in migration. Over all Australia rainfall patterns and especially soil moisture are negatively associated with migration frequency. Both alone and in combination with other climate variables, these explain high proportions of variance in migration. With high rainfall, temperature explains variance in migration frequency; latitude thus seems a surrogate for temperature under these conditions. Depending on climatic circumstances, either rainfall or temperature reflect uneven resource distribution, the ultimate source of selection for migration. (Session 6: Dispersal & Migration; Sun. 3:50pm; Rooke)
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60 CRAB SPIDER FIGHTS: INFLUENCES OF LEG AUTOTOMY, BODY SIZE, AND EXPERIENCE.
Gary N. Dodson
Biology Department, Ball State University, Muncie, IN 47306 (gdodson@bsu.edu)
Misumenoides formosipes males locate and guard penultimate females prior to mating. Male-male interactions associated with this guarding can involve grappling and bites, which are potentially lethal. Leg autotomy appears to be a strategy employed to avert the spread of toxin from a bite. To determine the influences of leg loss, body size, and previous contest experience on contest outcome, independent trials were conducted between opponents that differed with respect to only one of these three factors. Contrary to earlier results, more realistic experiments revealed no disadvantage for males missing a foreleg in contests with fully intact opponents. Body size, as expected, was a significant predictor of contest outcome. Unexpectedly, the outcome of an individual's initial contest was a significant predictor of the outcome of its next fight. The pairing of equivalently sized, novel opponents that had experienced contrasting results in their first contests resulted in previous winners defeating previous losers. The notion that a male's initial contest experience should dictate the result of his subsequent fights is not intuitively obvious and further tests are planned. (Session 12: Sexual selection II; Mon. 9:30-9:50am; Olin)
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120 MEASURING REPRODUCTIVE EFFORT BY PROXY
Jerry F. Downhower
Department of Evolution, Ecology, & Organismal Biology, The Ohio State University, Columbus, OH 43210 (downhower.1@osu.edu)
Resources devoted to reproduction may take many forms (e.g. nest defense) other than direct investment in gametes. Measurement of these other kinds investments has proven difficult. However, Downhower and Charnov (1998, PNAS 95:6208-6211) suggested the possibility of measuring these investments by proxy. This suggestion comes from analysis of the rules regarding how much more a female should invest in a litter of size C rather than producing a litter with one more offspring. The derived rule that was that the range of resources per offspring should be inversely proportional to litter size. When the total resources devoted to reproduction at any litter size is considered, then the range of resources devoted to reproduction should be the same for all litter sizes. When parental phenotypes, covary linearly with resources devoted to reproduction, then those traits should also show equal ranges of variation within each litter size category (except for litters of one). That is, the parental phenotype serves as a proxy for resources devoted to reproduction. The application of this rule to body size and other proxies for resources is explored. (Session 32: Sexual Selection V; Tues. 10:10-10:30am; Olin)
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23 INTRAUTERINE POSITION, ODORS, AND MATE CHOICE IN HOUSE MICE
*L. C. Drickamer1, Ami Sessions Robinson2 & Catherine A. Mossman3
1Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011-5640; 2Weber State University; 3Purdue University (Lee.Drickamer@nau.edu)
Odor preferences were used to test predictions concerning the effects of intrauterine position (IUP) as a basis for potential mate preference in house mice living in outdoor enclosures. The relationship between anogenital distance (AGD) and IUP was used as a bioassay for the degree of exposure of female and male fetuses to hormones in utero. The following predictions were made based upon laboratory work on the IUP phenomenon: (1) Female mice should prefer males with larger AGDs because such males are more aggressive, could potentially protect more resources, and are better parents than males with smaller AGDs; (2) Male mice should prefer females with smaller AGDs because they are better at reproducing than females with larger AGDs. These predictions were tested using wild house mice in 0. 1 ha field enclosures using the odor-baited trap technique. The most recent occupant of a trap, up to one week, is considered to provide the most salient odor in that trap. Both of the main predictions were upheld under the field testing conditions. Further, mice of both sexes tended to avoid odor cues from individuals of the same sex that had larger AGDs, probably to decrease the chance of an aggressive encounter that could result in injury. (Session 5: Communication II; Sun. 4:30pm; Forum)
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104 SPERM COMPETITION IN MEALWORM BEETLES: TIME BETWEEN MATINGS AFFECTS PATERNITY
*J. M. Drnevich, E. Hayes & Ronald L. Rutowski
Department of Biology, Arizona State University, Tempe, AZ 85287-1501 (drnevich@asu.edu)
In species where females mate with multiple times, males face strong sperm competition. The mechanisms by which males compete are affect by the manner of sperm transfer and storage. In yellow mealworm beetles (Tenebrio molitor), males transfer a spermatophore to females during copulation, but sperm release and storage occur later. We investigated how the timing of these events affected sperm competition by varying the interval between two matings: 1) before sperm release from the first spermatophore (> 5 minutes); 2) after sperm release but before spermatophore ejection (15-20 minutes); 3) after spermatophore ejection but before sperm storage (4 hours); and 4) after complete sperm storage (24 hours). The second male to mate sired a higher proprotion of offspring when the interval was > 5 minutes than during any other mating interval. Spermatophore ejection or sperm storage did not affect sperm precedence patterns. Males likely can only remove spermatophores and not free sperm of previous males. These results suggest that males may be selected to guard females after mating until their sperm are released. (Session 20: Sexual selection IV; Mon. 4:10-4:30pm; Olin)
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111 THE EFFECT OF HORMONE MANIPULATION ON PARASITE RESISTANCE IN THE HOUSE FINCH (CARPODACUS MEXICANUS)
*Renee A. Duckworth, Mary T. Mendonca & Geoffrey Hill
331 Funchess Hall, Department of Zoology, Auburn University, Auburn, AL 36830 (duckwra@mail.auburn.edu)
The immunocompetence handicap hypothesis is founded on the premise that high levels of androgen hormones suppress the immune response of males. Although this hypothesis has gained much attention among animal behaviorists, the immunosuppressive effects of androgens, such as testosterone and corticosterone, have yet to be demonstrated experimentally in any passerine bird. By manipulating hormone levels of the house finch, we were able to test the immunosuppressive effects of both testosterone and corticosterone on males' ability to resist infection by coccidia (Isospora sp.), a protozoan gut parasite and Mycoplasma gallisepticum, a bacterium. Among five treatment groups, no deaths occurred in control groups, whereas mortality occurred in all experimental groups (gonadectomized males, testosterone implanted males, and corticosterone implanted males). Although overall mortality between all groups did not differ significantly, mortality in gonadectomized males (N=9) did occur significantly more often (P=.015) than in control groups (N=18). These preliminary results indicate that hormone manipulation may have an adverse effect on male house finches. (Session 22: Mechanisms I; Tues. 10:10-10:30am; Gallery)
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113 SEX DIFFERENCES IN TESTOSTERONE-INDUCED IMMUNOSUPPRESSION IN EUROPEAN STARLINGS.
*Deborah L. Duffy, George E. Bentley, Deborah L. Drazen & Gregory F. Ball
Department of Psychology, Johns Hopkins University, Baltimore, MD 21218 (dduffy@ren.psy.jhu.edu)
It has been hypothesized that testosterone (T) may be immunosuppressive. This relationship has been demonstrated in some mammalian species. However, studies that have addressed this issue in birds have generally been inconclusive, some indicating immunosuppressive effects of T and others finding no relationship. The present study examined the effects of androgens on both cell-mediated and humoral immunity in male and female European starlings Sturnus vulgaris. Reproductively inactive starlings were administered silastic implants containing T. Six weeks after implantation, both cell-mediated and humoral immunity were evaluated via an intradermal delayed hypersensitivity test using the mitogen phytohemagglutinin (PHA) and the measurement of antigen-specific IgG titers with an enzyme-linked immunosorbant assay (ELISA). These initial studies suggest that T treatment significantly suppressed humoral immunity in females but not in males. There was a trend for T to suppress cell-mediated immunity in both males and females. Thus, male but not female starlings may have mechanisms to protect their humoral immune responses from high testosterone concentrations. (Session 22: Mechanisms I; Tues. 10:50-11:10am; Gallery)
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59 WINNER EFFECTS, LOSER EFFECTS AND DOMINANCE HIERARCHIES
Lee Alan Dugatkin
Department of Biology, University of Louisville, Louisville, KY 40292 (laduga01@athena.louisville.edu)
Winner and loser effects usually are defined as an increased probability of winning at time T, based on victories at time T-1, T-2, etc., and an increased probability of losing at time T, based on losing at T-1, T-2, etc., respectively. Despite some early theoretical work on winner and loser effects, these factors and how they affect the structure of dominance hierarchies have not been examined. I developed a computer simulation to examine winner and loser effects when such effects are independent of one another (as well as when they interact) and when combatants assess each other's resource holding power. When winner effects alone were important, a hierarchy in which all individuals held an unambiguous rank was found. When only loser effects were important, a clear alpha individual always emerged, but the rank of others in the group was unclear because of the scarcity of aggressive interactions. No study to date has documented both winner and loser effects and behavioral interactions when individuals are in large groups. Hopefully, the results of this model will spur on such studies. (Session 11: Resource Acquisition; Mon. 11:30-11:50am; Gallery)
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P43 THE COST OF LIMITED ATTENTION IN BLUE JAYS
*R. Dukas & A. C. Kamil
School of Biological Sciences, University of Nebraska, Lincoln, NE 68588-0118 (dukas@niko.unl.edu)
Neurobiological research on humans and monkeys indicates that attentional mechanisms direct the brain's limited computational resources to the most relevant information, filtering out less important information. These results imply that in at least some natural settings, animals are unable to simultaneously allocate sufficient attention to tasks that need to be carried out at the same time. We report the first direct evidence that attending to a difficult central task simulating foraging deters a bird's ability to detect a peripheral target, which could be a predator. Our results fill a gap between neurobiological and ecological studies by illustrating that although attention is an efficient filtering mechanism, limited attention may be a major cause of mortality in nature. (General Posters; Sun. eve; Terrace)
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P44 A DISTINCTION BETWEEN BASIC ORIENTATION MECHANISMS OF THE SALT MARSH PERIWINKLE, LITTORINA IRRORATA
*Maria L. Duva & M. Drew Ferrier
Department of Biology, Hood College, Frederick, MD 21701 (m_duva@hotmail.com)
The salt marsh periwinkle, Littorina irrorata, exhibits distinct behaviors in response to certain chemical stimuli found naturally in its environment by orienting to avoid danger or locate food. However, it is not clear whether a kinesis or taxis is used during these responses. The purpose of this study was to determine the orientation mechanisms used to respond to specific chemical stimuli. Littorina irrorata were exposed to chemical stimuli found commonly in their marsh environment. These stimuli included extracts derived from Spartina alterniflora, Callinectes sapidus and crushed conspecifics. Data collection consisted of measurements of the turning angles for each change of direction in each snail pathway. The mean of the turning angles for the pathways were used to determine the orientation mechanism used for each sitmuli. The results indicated that L. irrorata responded to S. alterniflora and C. sapidus by exhibiting a kinesis and to crushed conspecifics by exhibiting a taxis. Chemical cues appear to be more essential to L. irrorata when responding to crushed conspecifics than to C. sapidus and S. alterniflora. (General Posters; Sun. eve; Terrace)
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P45 RISK OF CUCKOLDRY AND TERRITORIAL USE PATTERNS IN WILLOW PTARMIGAN
*Perri K. Eason1 & Susan J. Hannon2
1Department of Biology, University of Louisville, Louisville, Ky 40292 USA; 2Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada (perri. eason@louisville.edu)
One means of assessing whether mate guarding is a function of territoriality is to examine whether territory owners use of space changes after pairing. We hypothesized that paired male willow ptarmigan (Lagopus lagopus) would avoid territory edges due to the potentially higher risk of cuckoldry there. To test this hypothesis, we mapped males territories at Chilkat Pass, British Columbia. Territories were divided into a boundary zone (0 - 10 m from a boundary), an intermediate zone (10 - 20 m from a boundary), and a core zone (> 20 m from a boundary). We then compared the behavior of bachelor and paired males. Before females settled, all males used the boundary zone extensively, spending on average over 70% of their time there. After females settled, bachelors continued to use primarily the boundary zones, spending over 85% of their time there; however, paired males remained in the territories cores over 90% of the time. Because floater males tended to stay near boundaries, these data suggest that mate guarding may be a significant function of territoriality and that the risk of cuckoldry may influence space use in territorial individuals. (General Posters; Sun. eve; Terrace)
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75 CHICKEN FOOD CALLS ARE FUNCTIONALLY REFERENTIAL
*Christopher S. Evans & Linda Evans
Department of Psychology, Macquarie University, Sydney, New South Wales 2109, Australia (chris@galliform.bhs.mq.edu.au)
Male chickens (Gallus gallus) produce characteristic food calls when they discover edible objects. Why do hens respond? One possibility is that they anticipate a feeding opportunity. Alternatively, female behaviour may be mediated by social cues, such as a low probability of male aggression. Two playback experiments were conducted to reveal the type of information encoded in food-associated vocal signals. Isolated hens were played food calls and their responses were compared with those evoked by ground alarm calls (which have similar acoustic characteristics) and by contact calls (which are produced under similar social circumstances). Hens responded to food call playbacks with anticipatory feeding movements, which were not evoked by either of the control sounds. This effect was highly specific; there were no differences between the call types in their effects on social behaviour. Similarly, there were no differences in the probability of orienting toward the loudspeaker or in locomotor activity. Chicken food calls appear to provide conspecifics with information about the presence of food. This property has not previously been demonstrated in any natural system of animal acoustic signals. (Session 14: Communication IV; Mon. 2:30-2:50pm; Rooke)
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154 WORKER-BASED MECHANISMS FOR COLONY GROWTH DIFFERENCES IN AFRICAN AND EUROPEAN HONEY BEES
*Jennifer H. Fewell & Jon F. Harrison
Department of Biology, Arizona State University, Tempe, AZ, 85287-1501 (j.fewell@asu.edu)
The difference in competitive success between African (Apis mellifera scutellata) and European (Apis mellifera ligustica) honey bees is largely generated by their growth and reproductive strategies. African colonies produce workers faster than European colonies, and swarm more frequently. Because honey bees are social insects, these colony-level differences are likely driven by variation in worker task performance. We tested this hypothesis by cross-fostering African and European workers in observation hives. Workers did not differ significantly in performance of most in-hive tasks, including brood care. However, African workers were significantly more likely to forage for pollen, the primary nutritional source for brood. In contrast, European workers were more likely to focus on nectar collection. These behavioral differences were correlated with differences in metabolic rates. Younger (in-hive) bees showed no subspecies variation in metabolic rates. However, flight metabolic rates were higher in foraging-age African workers and pollen foragers. These data support the assertion that the competitive advantage of African bees in the neotropics can be traced to a set of key genetically-based behavioral and physiological traits. (Session 31: Social behavior II; Tues. 3:50-4:10pm; Rooke)
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101 INTENSE HUNTING BY HUMANS MAY REDUCE RATTLING IN RATTLESNAKES REVISITED: ADDITIONAL RESULTS
*Corey L. Fincher & David L. Duvall
Department of Zoology, Oklahoma State University, Stillwater, OK 74078 (fincher@okstate.edu)
That predators can shape the biological communities in which they occur is firmly established. Moreover, this is true for pattern and variation in many antipredator adaptations among individuals in populations that are so affected. 'Super-predators', which we define here as ones that are essentially density-independent, may thus be hypothesized to result in even greater antipredator trait values. Last year, we presented preliminary findings of a test of the hypothesis that human super-predators (i. e., rattlesnake hunters) decreased rattling-related behavior in individuals comprising hunted populations but not unhunted pops of western diamondback rattlesnakes, Crotalus atrox, in southwestern Oklahoma. This year, we will present additional results that strengthen our conclusions that this hypothesis is thus far supported. (Session 19: Predator/Prey II; Mon. 4:50-5:10pm; Gallery)
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P46 MOLECULAR PHYLOGEOGRAPHY AND BEHAVIOR:INTRASPECIFIC VARIATION IN BREEDING SEASONS OF MINK
*Melissa A. Fleming1, Elaine A. Ostrander2 & Joseph A. Cook1
1University of Alaska Museum, 907 Yukon Drive, Fairbanks, AK 99775-6960; 2Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N., D2-190, Seattle, WA 98109-1024 (fnmaf@aurora.alaska.edu)
American mink (Mustela vison) on islands of the North Pacific Coast breed 1-3 months later than mainland populations at similar latitudes. This difference may result from adaptation to island/coastal vs. mainland/riverine habitats, but it may also reflect postglacial recolonization of the region from different source populations. To elucidate the origins of late breeding in island mink, we are using mitochondrial DNA sequencing to establish phylogenetic relationships among island mink and their possible ancestral populations in Alaska, Canada and the conterminous US. Preliminary results are consistent with the post-glacial origins of late breeding in island mink populations. To elucidate the relationship between breeding season and ecology, we are using microsatellite markers to detect interbreeding between island and mainland coastal populations and between coastal and riverine populations. Estimates of geneflow among island and mainland coastal mink examined so far are surprisingly low for a semiaquatic carnivore and may indicate reproductive isolation between island and mainland populations(General Posters; Sun. eve; Terrace)
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198 DISPOSABLE OFFSPRING IN BLACKBIRDS
*Scott C. Forbes1, Barb C. Glassey2, Suzanne Thornton1 & Lisa Earle1
1Department of Biology, University of Winnipeg, Winnipeg MB R3B 2E9; 2Department of Zoology, University of Manitoba, Winnipeg, MB R3T 2N2 (lsforbes@escape.ca)
More than a half century ago, David Lack suggested that parent birds may use brood reduction to track uncertain food, a process facilitated by asynchronous hatching of their young. Lack sketched the logic of asymmetric sibling rivalry: the phenotypic handicap imposed upon last-hatched marginal offspring renders their growth and survival conditional upon uncertain ecological conditions while buffering first-hatched core offspring from the inimical effects of overcrowding during periods of resource scarcity. Though subjected to numerous indirect tests in short-term studies, problems of experimental design, and in particular the difficulty of measuring resource levels, preclude any conclusions about the generality of Lack s hypothesis. Here we present the first direct test of Lack s hypothesis in a six-year study of marsh-nesting red-winged blackbirds (Agelaius phoeniceus). We show that (i) brood size tracks interannual variability in growth conditions, (ii) the tracking mechanism is based upon asymmetric sibling rivalry, and (iii) the phenotypic handicap hatching asynchrony buffers core offspring from resource shortfalls, but is reversible when growth conditions are favorable. (Session 40: Parental Care III; Weds. 1:50-2:10pm; Olin)
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14 EFFECTS OF ENDOPHYTE INFECTION ON HOME RANGE SIZE IN FEMALE PRAIRIE VOLES: A TEST OF THE FOOD-DEFENSE HYPOTHESIS
Gary M. Fortier
Dept. of Small Animal Science, Delaware Valley College, Doylestown, PA 18901 (fortierg@devalcol.edu)
The territoriality of female voles may be related to the quantity and quality of food available, ultimately serving as a form of food defense. We examined the relationship between food quality and patterns of space use in female prairie voles, Microtus ochrogaster, by radiotracking voles on grids of tall fescue. Fescue on four of the grids were infected with a fungal endophyte while three grids of uninfected fescue served as controls; the endophyte is known to reduce food quality for mammalian herbivores. We predicted that home range sizes would be larger on the endophyte-infected grids if female voles establish territories to defend food resources. We found no difference in the home range size of voles on endophyte-infected vs. uninfected grids. These results suggest that territoriality in female voles may serve functions other than the defense of food. (Session 3: Foraging I; Sun. 2:50pm; Olin)
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80 INTER-INDIVIDUAL SPACING AND ANTI-PREDATOR VIGILANCE IN SOCIALLY FEEDING BIRDS
*William E. Franklin III & Steven L. Lima
Dept of Life Sciences, Indiana State University, Terre Haute, IN 47809 (lsfrank@scifac.indstate.edu)
Despite a potentially strong influence of inter-individual spacing on vigilance in flocking birds, few studies address this phenomenon. We allowed wintering dark-eyed juncos Junco hyemalis and tree sparrows Spizella arborea to space themselves over a 33 m2 feeding site. Inter-individual spacing patterns and their relationship to vigilance were examined as a function of predation risk. Predation risk was manipulated by placing cover adjacent to, or 6 m away from, the feeding site. We expected inter-individual spacing to decrease with increasing risk, but no such effect was found. Nearest neighbor distances were usually within 1. 0 m, but much larger distances were often observed. Birds were closer together than expected under various null hypotheses, but nearest neighbor distances could clearly have been smaller. Vigilance increased as birds became more widely spaced, which begs the question of why nearest neighbor distances were often fairly large. Aggression provides an obvious answer, but was rare at our site, even in dense flocks. We suspect that predator targeting behavior may help explain this paradoxical result. (Session 15: Predator/Prey I; Mon. 2:30-2:50pm; Gallery)
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203 SOCIAL LEARNING OF CALLS IN CAROLINA CHICKADEES, POECILE CAROLINENSIS
*Todd M. Freeberg & Jeffrey R. Lucas
1Department of Biological Sciences, Purdue University, West Lafayette, IN 47907 (freeberg@bilbo.bio.purdue.edu)
We tested whether the chick-a-dee call of Carolina chickadees changes with a novel social context when individuals join new flocks. For each experimental flock, we captured a male (the joiner) from one site and placed him into an aviary with a male and two females (the flockmates) captured from another site. Before joining the birds (pre-flock), and after they were together for 3-4 weeks (post-flock), we recorded chick-a-dee calls of the four birds. In playback experiments, the flockmates responded differently to the joiner's pre-flock calls relative to his post-flock calls; this functional test indicated that the joiner's calls had changed during the exposure to the flockmates. Structural analyses of calls indicated that some characteristics of the dee notes of the joiner's calls, including bandwidth and peak frequencies, converged towards those of the flockmates. These data indicate that an individual's calls can change when it joins a new flock, and point to some of the important social interactions that may facilitate this vocal learning. (Session 41: Development III; Weds. 3:50-4:10pm; Forum)
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168 ANALYZING THE SOCIAL RELATIONSHIPS OF NEONATAL DOLPHINS
*Deborah R. Fripp & Peter L. Tyack
Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (dfripp@whoi.edu)
The ability to combine social interactions between animals into social relationships is essential to the understanding of the animals social experience. This is particularly important to studies of the social influences on the development of young animals. To evaluate the social relationships of neonatal dolphins, focal samples were taken of dolphin mothers and calves during the first weeks of four captive-born calves. Association patterns, affiliative interactions, nursing, and calf-protection behaviors were recorded. The interactions were analyzed with loglinear models, multidimensional scaling, and hierarchical cluster analysis to determine the relationships that occurred between the calves and the adults. Multiple measures were necessary to distinguish the subtle relationships between the dolphins. Each calf had many interactions with one adult, generally the calf s mother. However, an analysis of a prolonged alloparenting incident demonstrated that the social relationship between mothers and calves was a care-giving relationship independent of their genetic relationship. The calves' relationships with most other adults were characterized by few interactions. One calf had a third type of relationship with some adults, characterized by an intermediate number of interactions. (Session 33: Development I; Weds. 11:10-11:30am; Forum)
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208 INNATE CHEMOSENSORY RECOGNITION OF PREDATORS BY TADPOLES OF THE AMERICAN TOAD
*Jonathan A. Gallie, Ronald L. Mumme & Scott A. Wissinger
Department of Biology, Allegheny College, Meadville, PA 16335 (galliej@alleg.edu)
Although chemosensory recognition of predators by larval amphibians is well known, few studies have determined whether chemosensory recognition is innate or learned. We addressed this issue by exposing laboratory-reared (naive) and wild-caught (experienced) tadpoles of the American toad (Bufo americanus) to water-borne chemical cues of two different predators (bluegill sunfish Lepomis macrochiras and larvae of the odonate Anax junius) and a non-predator (red-spotted newt Notophthalmus viridescens). Compared to control tadpoles exposed to plain water, tadpoles exposed to chemical cues of the two predators showed a significant increase in shelter use, a significant increase in aggregation, and a significant decrease in overall activity. However, the behavior of tadpoles exposed to chemical cues of the nonpredatory newt was identical to that of control tadpoles. Most importantly, we found no difference in the anti-predator behavior of laboratory-reared and wild-caught tadpoles. We conclude that chemosensory recognition of predators in toad tadpoles is an innate ability. (Session 42: Predator/prey IV; Weds. 3:50-4:10pm; Gallery)
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164 EVOLUTION AND PLASTICITY IN COLOR AND BEHAVIOR IN RESPONSE TO MULTIPLE SELECTION PRESSURES: A COMPARISON OF TWO SISTER SPECIES, AMBYSTOMA BARBOURI AND AMBYSTOMA TEXANUM
*Tiffany S. Garcia & Andrew S. Sih
Department of Biology, University of Kentucky, KY 40506 (tgarcia@ceeb.uky.edu)
In nature, organisms face a multitude of conflicting selection pressures that influence physiological, morphological and behavioral traits. Two such adaptive traits are color and behavior, both of which can be hormonally and environmentally regulated adaptive responses to environmental conditions. The sister species Ambystoma barbouri and Ambystoma texanum differ in habitat and selection pressures, and thus differ in mean color and behavior. This study focuses on the individual plasticity and species variation in physiological color change, background matching and refuge use under risk of predation, ultraviolet radiation and habitat drying. We examined temperature response over ontogeny, which relates to overall development, and found that late stage larvae are darker than early stage larvae in cold temperatures due to melanocyte-stimulating hormone release. Early stage larvae were predominantly dark regardless of temperature. Predation risk, an additional selection pressure, causes individuals to increase refuge use as well as respond with physiological color change. Exposure to ultraviolet radiation causes individuals to change behavior as well as to physiologically alter integument color. The combination of these selection pressures leads to compensation strategies and trade-offs in resultant color and behavior. This research determines the strength of these selection pressures and the adaptive response to multiple environmental factors. (Session 32: Evolution and SS II; Tues. 5:10-5:30pm; Olin)
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186 DISSOCIATING KNOWLEDGE FROM ACTION IN THE BANK VOLE
*Joseph P. Garner1 & Georgia J. Mason2
1Dept. Animal Science, University of California, One Shields Avenue, Davis, CA 95616, USA; 2Dept. Zoology, Oxford University, South Parks Road, Oxford, OX1 3PS, UK (jpgarner@ucdavis.edu)
In many human pathologies characterized by abnormal repetitive behavior, the translation of knowledge into action is impaired. For instance, autistic patients persist in repeating habitual responses despite reporting that they know that these responses are inappropriate (and wishing to avoid them). We investigated whether animals displaying abnormal repetitive behaviors called stereotypies had similar impairments. Eight bank voles were videotaped, and their degree of stereotypy assessed. They were taught a spatial discrimination in a Y-maze, which was then extinguished. Two measures were used to determine when each vole understood the extinction task: when it choose both maze arms with equal probability; and when it choose both with equal latency. Voles did not reach criterion on both measures on the same trial. Furthermore, upon reaching the criterion of choosing both sides with equal probability, high stereotypy voles showed smaller changes in choice latencies than lower stereotypy voles (R2=.942; p=0.003). Thus, as with humans, abnormal repetitive behavior in voles is correlated with an impairment in the ability to translate knowledge into action. (Session 37: Development II; Weds. 2:30-2:50pm; Forum)
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178 AN EXPERIMENTAL EVALUATION OF THE SIGNAL OF STATUS HYPOTHESIS TO ACOCUNT FOR SCROTAL COLOR VARIABILITY IN CAPTIVE VERVET MONKEYS (CERCOPITHECUS AETHIOPS SABAEUS).
Melissa S. Gerald
Department of Anthropology, The University of California, Los Angeles, CA 90095 (melissagerald@hotmail.com)
The importance of color differences between the sexes in fish, amphibians, lizards and birds has elicited tremendous attention among evolutionary biologists. While primates are considered to display the most conspicuous coloration in mammals, little is known about the function of this color. The present study demonstrates that the Signal of Status Hypothesis can explain scrotal color variability in adult vervet monkeys (Cercopithecus aethiops). This study experimentally evaluated this hypothesis by analyzing the social interactions between pairs of unfamiliar adult male vervets matched for size. Here I show that dark males were found to be dominant to pale males (N=23 pairs, p<0.011). Furthermore, same color pairs were more likely to exchange aggression than different color pairs (N=61 pairs; p<0.007). While painted males did not achieve the dominant status when faced with pale opponents (N=10 pairs; p<0.754), higher rates of aggression were found for same color pairs relative to different color pairs when males were painted to resemble naturally dark males (N=20 pairs; p<0.020). By demonstrating that color treatment alters social interactions between males, these results provide the first evidence in primates for the effect of color on social behavior and these results suggest that scrotal color may function as a signal of status. (Session 35: Communication VI; Weds. 11:30-11:50am; Rooke)
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16 COOPERATION AND CONFLICT IN FEMALE WOOD MICE (APODEMUS SYLVATICUS) RAISING YOUNG TOGETHER
*Gabriele Gerlach
Faculty of Biology, University of Constance, 78457 Konstanz, Germany (gabi.gerlach@uni-konstanz.de)
According to Hamilton (1964) altruistic behavior should be dependent on relatedness between cooperating individuals. To date, cooperative breeding has been observed mainly in species living in family units with closely related females. To evaluate if family units and genetic relatedness were essential for the evolution of cooperative behavior, we studied reproductive success of communally nursing wood mice where family units do not coexist, but communal nesting occurs under natural conditions. In laboratory experiments the number of weaned offspring, one measure of female reproductive success, was compared when one female was raising young alone, with a sister, a daughter and an unrelated female. Maternal care was analyzed by behavioral observations. When females raised offspring together, one female always weaned significantly more offspring than the other. No difference were detected in relation to female relatedness. Maternal care was significantly lower in cooperating females indicating an advantage to communal versus single offspring rearing. These data indicate that cooperative breeding has evolved as a behavior in which one female exploits the other. Whether the less successful partner cooperates or not may depend on environmental conditions e. g. availability of unoccupied breeding sites. (Session 4: Parental Care I; Sun. 1:50pm; Gallery)
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P47 POST-CONFLICT RECONCILIATION IN RINGTAILED LEMURS
*Joseph S. Giammalvo & Michael E. Pereira
Department of Biology, Program in Animal Behavior, Bucknell University, Lewisburg, PA 17837 (giammlvo@bucknell.edu)
Data collected on ringtailed lemurs, Lemur catta, over a five-year period (1989-1993) are used to evaluate the potential existence of post-conflict reconciliation in this prosimian primate as well as to examine its role in social structure. Two semifree-ranging groups were studied at the Duke University Primate Center in a forest enclosure of 9ha. Data were collected in one- to three-hour morning and afternoon sessions. Fifteen-minute focal animal samples were conducted on all juvenile and adolescent group members during which point samples of neighbors were recorded at five-minute intervals. Using the selective attraction, rate, and matched-control methods, suggestive evidence of a conciliatory tendency is revealed, contrary to the single prior report for this species. Reconciliation is considered a useful mechanism for group-living animals to maintain group cohesion. By examining the way reconciliation is influenced by degree of relatedness, conflict intensity, and identity of conflict initiator, we begin to illuminate roles for reconciliation in ringtailed lemur social organization. (General Posters; Sun. eve; Terrace)
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P48 TEMPORAL AND SPATIAL HOME RANGE OVERLAP OF FERAL HOUSE MICE, MUS DOMESTICUS
*L. L. Gillie, L. C. Drickamer & K. R. Audette
Department of Biology, Elmira College, Elmira, NY 14901 (lgillie@elmira.edu)
Home ranges of mice living in commensal situations are relatively small with little overlap, however, in the field, home ranges are larger and seem to overlap both within and between sexes. Therefore, if data from an entire field season are pooled, home range size and degree of overlap may be overestimated. A more accurate measure of home range size should include spatial and temporal shifts as the season progresses. Distributions of seven different populations of mice in two different years were studied using Sherman live-traps. Male-male overlap was higher than female-female overlap in most time intervals. Intersexual overlap was much greater than intrasexual overlap. Home ranges calculated for captures within a two month interval were smaller and spatially shifted compared with the home ranges calculated for the entire season, thus predictions of animal interactions should take into account the time period over which animals were observed. Eventually, information about location will be combined with genetic data to see if parentage can be predicted by home range overlap. (General Posters; Sun. eve; Terrace)
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199 NESTLING BEGGING AND THE INITIATION OF ENDOTHERMY IN RED-WINGED BLACKBIRDS
*Barb C. Glassey1 & Scott C. Forbes2
1Department of Zoology, University of Manitoba, Winnipeg, MB R3T 2N2; 2Department of Biology, University of Winnipeg, Winnipeg MB R3B 2E9 (BGLASSEY@ESCAPE.CA)
Nestlings of altricial passerines begin life as ectotherms, and make the transition to endothermy during early development. Red-winged blackbirds (Agelaius phoeniceus) begin the transition to endothermy on day 5, midway through the nestling period. Blackbird parents hatch their eggs asynchronously, resulting in broods with mixed ages. This means that as first-hatched offspring are reaching endothermy, their later hatched siblings are still ectothermic. Physiological advantages associated with endothermy, including improved motor skills and faster response time, are known to enhance begging performance. We examined the influence of size and developmental disparities in relation to performance in intrabrood begging competitions of nestling Red-winged blackbirds. Broods were assessed at three stages: i) all nestlings ectothermic; ii) endothermy initiated in first-hatched nestlings, last-hatched nestlings ectothermic (transitional stage); iii) endothermy initiated in all nestlings. Response time determined feeding success, and endothermic nestlings were faster than ectothermic nestlings. The initiation of endothermy exaggerated the gap in competitive ability between first- and last-hatched nestlings, contributing to increased mortality at the transitional stage. (Session 40: Parental Care III; Weds. 2:10-2:30pm; Olin)
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P49 EFFECTS OF A PERCEIVED PREDATION RISK ON CHICKADEE BODY WEIGHT AND FOOD CACHING
*Amy E. Gordon & David F. Sherry
Department of Psychology, University of Western Ontario, London, Ontario, Canada, N6A 5C2 (agordon@julian.uwo.ca)
Increased fat reserves in passerines protect against starvation, but are known to decrease flight speed and agility, which should increase predation risk. Theoretically, there should be a trade-off between the starvation risk and the predation risk of maintaining lowered fat reserves and body weight. Experimental results, however, have not been clear cut. We tested how black-capped chickadees (Parus atricapillus) adjust both internal (fat) and external (caches) reserves under a predation threat. Over 3 6-day blocks birds were exposed to a taxidermic mount of either a sharp-shinned hawk (Accipiter striatus) or a red-winged blackbird (Agelaius phoeniceus). Within a block, taxidermic mount days were alternated with baseline days. Evening weight and caching were significantly lower on the hawk mount days and higher on the following baseline days. No such effects occurred for red-winged blackbird exposure. It appears that following hawk exposure, the birds responded to a perceived predation threat with decreased weight and foraging, while the next day, the birds responded to a perceived starvation threat with increased weight and foraging. (General Posters; Sun. eve; Terrace)
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152 A COMPARISON OF FOUR CORVID SPECIES IN A WORKING AND REFERENCE MEMORY TASK
Kristy L. Gould-Beierle
Nebraska Behavioral Biology Group, Biology Department, University of Nebraska, Lincoln, NE 68588 (klg21@cornell.edu)
Four species of birds in the corvid family were tested in an open room 12-hole radial maze. The species used included the Clark's nutcracker, pinyon jay, and Western scrub jay, which all vary in food-storing behavior in the wild, and the Eurasian jackdaw which does not store food at all. The design of the experiment allowed testing of both working and reference spatial memory in the same task. Eight of the holes were used for the working memory portion of the task. The remaining two holes were used for the reference memory portion and never contained seeds. Acquisition of the task was analyzed by calculating both percent correct and errors made during each trial. Both species of jays performed significantly better than the jackdaws and qualitatively better than the nutcrackers in the working memory component of the maze. There were no species differences in the reference memory component of the maze. (Session 30: Foraging III; Tues. 5:10-5:30pm; Gallery)
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P8 VISITOR EFFECTS ON THE BEHAVIOR OF TWO CAPTIVE JAGUARS
James C. Ha & *Rebecca L. Jacobs
Department of Psychology, University of Washington, Seattle, WA. 98195 (Fiona379@AOL.com)
A number of studies have reported finding significant effects when correlating visitor density and intensity with captive animal behavior, and the present study attempted to ascertain whether this is the case for jaguars (Panthera onca). Two captive jaguars were observed at the Woodland Park Zoological Gardens (Seattle, Washington) for changes in behavior as a function of visitor density and intensity (number of people and their noise level). The behaviors measured included pacing, skip-pacing, aggression, social, and non-visible. Preliminary results indicate that intensity, and not density, has an effect on pacing (p=0.00001); and that density and intensity have an conditional effect on nonvisible behavior. (Founders Award poster; Sun. eve; Terrace)
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76 FORM FITS FUNCTION IN THE LOW-FREQUENCY CALLS OF EMUS
*Sylvia L. Halkin1 & Christopher S. Evans2
1Department of Biological Sciences, Central Connecticut State University, New Britain, CT 06050; 2Department of Psychology, Macquarie University, Sydney, New South Wales 2109, Australia (halkins@ccsu.edu)
Emus (Dromaius novaehollandiae) are large, flightless, Australian birds whose sparsely distributed food often leads to long distances between conspecifics. Adults communicate using low-frequency calls produced with the aid of a unique inflatable pouch that opens from the trachea, near the base of the neck. Females have larger tracheal pouches, and we have found that they can produce lower-frequency calls (~60-210 Hz), than males (~140-270 Hz). Emus appear to change the pitch of their calls by varying the degree of pouch inflation. Our observations of free-ranging emus indicate that males use their calls to communicate with conspecifics at relatively close range (0.5-15 m). Females calling to other emus at these distances use frequencies above ~100 Hz. However, unpaired females perform conspicuous mate-attraction displays, accompanied by calls in the 60-80 Hz range. The low frequencies of these calls promote long-distance propagation. Audible distance may be further augmented by the posture of calling females, which characteristically hold their heads close to the substrate. People have reported hearing emu mate-attraction calls from 2 km away. Presumably emus, whose hearing is biased toward low frequencies, can also hear them from at least this distance. (Session 14: Communication IV; Mon. 2:50-3:10pm; Rooke)
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183 SEXUAL SELECTION AND SPECIES IDENTIFICATION IN XIPHOPHORUS PYGMAEUS
*Shala J. Hankison & Molly R. Morris
Department of Biological Sciences, Ohio University, Athens, OH 45701 (sh174591@oak.cats.ohiou.edu)
Little is known about how multiple female preferences interact. Using a repeated measure design we compared the preferences of individual Xiphophorus pygmaeus females for two visual signals. X. pygmaeus, which are small and barless, are found sympatrically with X. cortezi, which are large and polymorphic for bars. Female X. pygmaeus preferred large, barless X. cortezi males over their own smaller, barless males, suggesting that body size is not used as a species specific signal, but functions in sexual selection. Given a choice between two similarly sized X. cortezi males, females preferred barless males (like their own) over barred males suggesting that vertical bars may play a role in species identification. In a final study, X. pygmaeus females were presented with barred X. cortezi and smaller, barless conspecifics. Female preference for large X. cortezi males significantly decreased when bars were added, however there was no significant preference for either species at the population level. This lack of an overall preference will be discussed. (Session 36: Sexual selection VI; Weds. 11:30-11:50am; Olin)
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100 HOW CLEVER IS AN OCTOPUS? SOME TESTS OF PRIMARY AND SECONDARY DEFENSE ON A CORAL REEF.
*Roger T. Hanlon1 & John W. Forsythe2
1Marine Biological Laboratory, Woods Hole, MA 02543; 2Marine Biomedical Institute, U Texas Med Br, Galveston, TX 77555 (rhanlon@mbl.edu)
Cephalopods have large brains and are often called intelligent based mostly on anecdotal observations. We tested the flexibility of octopus defence behaviors in their natural habitats. First: how do soft-bodied octopuses achieve camouflage on such varied backgrounds while foraging? They used 6 mechanisms of crypsis, were often purposely conspicuous, and displayed exceptional rates of polyphenism. Second: once discovered, how diverse and flexible are their secondary defense responses? A huge amount of sensory processing and behavioral output occurred over the course of a dozen repeated attacks as the octopuses swam over varied substrates during ten minutes. Octopuses showed a wide array of unpredictable responses requiring rapid decision-making that took into account the immediate habitats they were swimming over. Overall, octopuses showed highly diverse defenses that required a great deal of CNS processing that was certainly adaptive (i.e. clever) but did not necessarily require intelligence in the sense that the term is applied to mammals and primates. (Session 19: Predator/Prey II; Mon. 4:30-4:50pm; Gallery)
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P50 SPERM COMPETITION IN SMALL-MOUTHED SALAMANDERS
W. E. Harris
Department of Biological Sciences, Purdue University, West Lafayette IN 47907 (eharris@bilbo.bio.purdue.edu)
The effect of sperm competition intensity and the expected reproductive payoff on optimal ejaculate expenditure is modeled using stochastic dynamic programming. Parameters values used in the model were based on data from small-mouthed salamanders Ambystoma texanum. Multi-male breeding aggregations form in this explosively breeding species in early spring, individual males may deposit 60 or more spermatophores at a given aggregation, and males can participate in multiple breeding aggregations. Females induct ten or more spermatophores at an aggregation prior to depositing eggs. Sperm reserves are produced prior to over-wintering and are not replenished during the short breeding season. In the model, the number of males and females present in a given aggregation is assumed to be Poisson distributed. A male's reproductive payoffs are assumed to be proportional to number of spermatophores that he contributes relative to competing males and the number of females in the aggregation. Unlike previous models in which males can replenish their sperm supplies (e. g., Parker et al., 1997), my model explicitly treats sperm as a limiting resource, and thus should be more applicable to species with short breeding seasons. (General Posters; Sun. eve; Terrace)
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109 THE INCREASING ROLE OF ANIMAL BEHAVIOR IN VETERINARY MEDICAL EDUCATION
B. L. Hart
School of Veterinary Medicine, University of California, Davis, CA 95616 (blhart@ucdavis.edu)
Given the obvious importance of animal behavior to owners of companion animals as well as livestock, it is perhaps surprising to see great disparities in the amount, level and nature of animal behavior information presented to veterinary students. Required didactic coursework ranges from broad ethological coverage, to domestic animal behavior only, to virtually nothing. Increasingly, elective courses in basic or clinical animal behavior are becoming available to veterinary students. Clinical instruction ranges from opportunistic case workup to well- established clinical programs with elective senior rotations and as many as two full-time residents working on board certification. It is predicted that client demand and economics will drive a curricular expansion of clinical and basic animal behavior. For example, the advent of drugs such as the two recently FDA-approved drugs for problem behavior in dogs, with the media hype associated with the launch of these drugs, will stimulate curricular development. Also, the availability of board-certification through the American College of Veterinary Behaviorists is leading to expansion of clinical animal behavior. (Session 21: Education Symposium; Tues. 10:50-11:10am; Forum)
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202 DO OLD DOGS GET COGNITIVE DYSFUNCTION?
B. L. Hart, M. J. Bain & J. C. Neilson
School of Veterinary Medicine, University of California, Davis, CA 95616 (blhart@ucdavis.edu)
Despite problems with the semantics, the answer is yes, now that an FDA-approved drug, selegiline (Anipryl, Pfizer), is available to treat the canine cognitive dysfunction syndrome. The signs of cognitive dysfunction, categorized under disturbances of, 1) disorientation, 2) social interaction, 3) the sleep/wake cycle and 4) house training, were significantly improved in old dogs by selegiline in an extensive double-blind, placebo-controlled study. Two other studies shed light on the prevalence and rates of change in the four cognitive dysfunction categories listed above. All information was collected by systematic interviews of dog owners. Conservative scoring for dogs, 11 years of age and older, as positive for one category or positive for at least two categories (the severe level), revealed that within 16 months there is typically a 20 percent increase in the number of dogs positive for these levels of cognitive impairment. Among 16-year-old dogs 65 percent were positive for the severe level. A compelling question is: does the widespread practice of gonadectomy predispose our pet dogs to age-related cognitive impairment? (Session 41: Development III; Weds. 3:30-3:50pm; Forum)
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128 AN INTERNATIONAL VIEW OF COMPANION ANIMAL BEHAVIOR AND HUMAN-ANIMAL INTERACTIONS
Lynette A. Hart
Center for Animals in Society, School of Veterinary Medicine, University of California, Davis, CA 95616 (lahart@ucdavis.edu)
During the past two decades in the United States, the acknowledged importance of companion animals within their human families has greatly expanded. The pervasive social volunteer movement of offering animal-assisted therapy and activities, the validation of grieving when a companion animal dies, the growing community support for humane societies, professional treatment for problem behavior in animals, and the expansion of specialized training of assistance dogs are just some of the societal changes and movements reflecting the enhanced importance of companion animals. These emerging trends have captivated the veterinary communities and sometimes the public in countries of Europe and Asia, leading them to sponsor numerous educational symposia featuring U. S. speakers. In turn, with leadership from the veterinary profession, these various countries are adapting the information and creating their own distinctive programs that draw on the U. S. experience. A particular focus will show how animal- assisted therapy, pet loss support, service dog training, and clinical animal behavior have developed rather quickly in Japan. (Session 25: Education Symposium; Tues. 2:30-2:50pm; Forum)
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68 THE REPRODUCTIVE STRATEGY OF A BROMELIAD-BREEDING TREE FROG
Lynn F. Haugen
Department of Zoology, University of Oklahoma, Norman, OK 73019 (lhaugen@ou.edu)
I investigated the reproductive strategy of the laughing frog, Osteocephalus planiceps, in relation to its larval ecology. This species deposits eggs in water-filled leaf axils of bromeliads where food resources for developing tadpoles are limited. To determine the life history traits that allow this species to exploit these harsh larval habitats, I studied a population of O. planiceps within a 3600 m2 area that contained both natural and artificial oviposition sites (water-filled cups). Throughout tadpole development, females returned periodically to their oviposition sites, paired with males and deposited fertilized eggs that were eaten by resident tadpoles. In addition to oophagy, tadpoles cannibalized fellow larvae. Larval mortality was extremely high (due to causes other than cannibalism) and females often returned to sites devoid of tadpoles. When a clutch failed or when all tadpoles emerged, the next oviposition initiated a new primary clutch. The reproductive strategy of this species differs from most other anuran trophic feeders in that the trophic eggs are fertilized. Through over-production of young, males and females not only provide a food source for their primary clutches, but also quickly create replacement offspring in the event of unpredictable loss. (Session 13: Allee Award session; Mon. 1:50pm; Forum)
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106 LINKS BETWEEN MATING DISPLAYS AND PREDATOR AVOIDANCE IN MALE CRICKETS
Ann V. Hedrick
Neurobiology, Physiology & Behavior, University of California, Davis, Davis, CA 95616 (avhedrick@ucdavis.edu)
Are males with conspicuous mating displays any more, or less cautious about predation risk than males with less conspicuous displays? Laboratory experiments were designed to address this question using a field cricket, Gryllus integer. In this species, females prefer males with longer calling bouts, and calling bout length is a heritable trait. Calling bout lengths of field-caught males were measured as they called undisturbed, and predator-avoidance behavior of these males was measured independently as the latency to emerge from a shelter when placed in an unfamiliar environment. Latency to emerge was consistent (repeatable) over time for individual males, and latencies were longer for males with longer bouts. These data suggest that males with long bouts, whose calls are preferred by females, may compensate for their conspicuous mating displays by being especially cautious when the apparent risk of predation is increased. (Session 20: Sexual selection IV; Mon. 4:50-5:10pm; Olin)
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13 LIFE-HISTORY CONSEQUENCES OF A GENETICALLY-BASED FORAGING POLYMORPHISM IN DROSOPHILA MELANOGASTER
Linden E. Higgins
Department of Entomology, University of Massachusetts, Amherst, MA 01003 (linden@ent.umass.edu)
To experimentally examine the evolutionary consequences of different behaviors, it is necessary to separate the behavior from the environmental context: to generate alternate behaviors in the same environment and to generate the same behavior in different environments. Since most behavioral variation is context-dependent, this is often difficult or impossible to accomplish. In Drosophila melanogaster, there is a simple Mendelian trait that determines foraging behavior in both larvae and adults. Larval survival to maturity is dependent not only upon an individual s foraging phenotype but also upon both the density of larvae and the foraging phenotypes of competing larvae. (Session 3: Foraging I; Sun. 2:30pm; Olin)
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214 WHATEVER YOU SAY, DEAR! MALE BUDGERIGARS IMITATE THEIR MATE'S CALLS
*Arla G. Hile & Georg F. Striedter
Dept. of Neurobiology & Behavior, University of California, Irvine CA 92697-4220 (hile@darwin.bio.uci.edu)
The budgerigar (Melopsittacus undulatus), a small species of parrot, can learn new vocalizations throughout life and is therefore widely used as a model system for studying various aspects of vocal learning. It is not known, however, why parrots imitate sounds. In order to test the hypothesis that vocal imitation in this species is related to pairbonding, we recorded the call repertoire of each of nine male and nine female adult budgerigars who were unfamiliar to one another, then placed them into pairs. We sampled their vocalizations weekly and conducted twice weekly behavioral observation sessions. Within an average of 2.1 weeks, male budgerigars reliably imitated the contact calls of their mates, while the females calls remained relatively stable. The accuracy of these imitations is positively correlated with the amount of courtship feeding observed. We conclude that vocal imitation in adult budgerigars is a component of male courtship behavior. Many studies on budgerigars have been limited by a lack of a behavioral paradigm to elicit vocal imitation reliably. Our study remedies this and thereby serves as a foundation for a broad array of subsequent studies on vocal learning. (Session 41: Development III; Weds. 4:10-4:30pm; Forum)
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149 COLOUR CONSTANCY IN ITALIAN HONEYBEES WHEN INTERFLORAL DISTANCES VARY
*P. S. M. Hill, J. Hollis & H. Wells
Faculty of Biological Science, University of Tulsa, OK 74104 (peggy-hill@utulsa.edu)
Italian honeybees Apis mellifera ligustica, offered equal rewards in pedicellate artificial flowers varying in colour and interfloral distance, exhibit behaviour dependent on the colour-dimorphism tested. If colours have similar spectral reflectance, and are clustered relatively closely in the bee's visual space, individuals visit the closest flower with higher frequency. With a blue-white dimorphism, bees increase frequency of visits to the closest flower with a 2ul reward (72%), when compared with a 6ul reward (57%). However, even when all flowers were identical in morphology and reward (all blue) and only interfloral distance was varied, bees still did not always (57%) visit the closest flower. A dramatic difference was seen with a shift in flower colour. When the choice was between yellow and blue, colours known to elicit constancy behaviour and known to be quite separated in the bee colour space, bees visited the closest flower only 5% of the time. Variation in reward volume did not lead to different behaviour. These results contrast with reports in the liberature that foraging behaviour is independent of colour. (Session 30: Foraging III; Tues. 4:10-4:30pm; Gallery)
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147 FACTORS INFLUENCING THE FORAGING SUCCESS OF THE GREAT BLUE HERON (ARDEA HERODIAS)
William D. Hobbs
East Stroudsburg University, East Stroudsburg, PA 18301 (eoverholt@enter.net)
This study had two objectives. The first was to determine how environmental and behavioral variables affect foraging success. The second goal was to determine the parameters and extent to which Great Blue Herons (Ardea herodias) modify behavior to maximize success. Foraging strikes and capture made by the herons were observed for 100 periods averaging 10 minutes each. This data included environmental conditions and movements of feeding herons. The results show that foraging success was influenced by wind, lighting, prey abundance, and behavioral variables. Behavioral variables include foraging location, wading depth, search movements and striking postures. The results also indicate that the key operative decisions for maximizing success are foraging location and striking posture. The adult capture efficiencies were significantly greater than those of immature birds. The data shows a greater use of more efficient strike postures by the adult birds as one possible explanation. These results contribute to our understanding of condition requirements for successful foraging in herons and add insight to the concept of optimal foraging in general. (Session 30: Foraging III; Tues. 3:30-3:50pm; Gallery)
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P51 COMPARING WING MORPHOLOGY OF THE PRAIRIE MOLE CRICKET
*C. Hoffart & P. S. M. Hill
Faculty of Biological Science, University of Tulsa, OK 74104 (hoffartcm@centum.utulsa.edu)
The prairie mole cricket Gryllotalpa major is a burrowing insect native to the tallgrass prairies of the southern United States. The male produces a loud, long-range calling song at sunset in April and May. In addition, he produces courtship and aggressive calls. No female calls have been described. The cricket wing is used for producing sounds. Rubbing the plectrum of one wing along the file of the other produces the chirp. Both of these structures are essential to cricket sound production. Wing morphology of male, female and juvenile specimens were compared from Scanning Electron Microscope (SEM) photographs. In the male, the file, plectrum, harp and mirror were recognizable. The file had detailed teeth used for sound production. The female wings were comprised of similar features but were altered in shape and size. The female had a different vein pattern and file teeth were less defined. The juvenile was similar to the female but lacked a file. The SEM photographs indicate the adult male to be the only prairie mole cricket capable of producing loud, long-range calls due to his wing morphology. (General Posters; Sun. eve; Terrace)
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156 THE DISTINCTION BETWEEN SOCIAL EXPLORATION AND SOCIAL TOLERANCE IN A MONOGAMOUS PRIMATE, THE TITI MONKEY (CALLICEBUS MOLOCH)
*Kurt A. Hoffman, Sally P. Mendoza & William A. Mason
Department of Psychology, University of California, Davis, CA 95616 (kahoffman@ucdavis.edu)
In two separate studies, we investigated the proximate mechanisms underlying natal dispersal and pair formation in young adult titi monkeys. In one study we removed mature titis (N=20) from their families and housed them with a heterosexual partner. Gonadal hormone levels were not altered by pair formation, but subjects displayed adult-typical sexual behavior, and all pairs bred successfully. In another study, we provided young adult titi monkeys (N=16) with the opportunity to voluntarily leave the proximity of their natal groups and interact with other young adults of both sexes. Although young females left the vicinity of their parents more quickly than males, neither males nor females explored the available social or physical environment. Young adults approached and interacted with each other on only six of 64 test days. Our results indicate that while young titi monkeys react amicably to the presentation of a heterosexual partner, they are not highly motivated to leave the proximity of their parents and actively explore new social opportunities. (Session 31: Social behavior II; Tues. 4:30-4:50pm; Rooke)
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150 THE ROLES OF HANDLING TIME AND FLOWER COLOR IN FORAGING OF HONEYBEES
*J. Hollis, P. S. M. Hill & H. S. M. Wells
Faculty of Biological Science, University of Tulsa, OK 74104 (jeremy-hollis@utulsa.edu)
Italian honeybees foraging on yellow and blue artificial flowers become constant to one color, rarely sampling the other. With blue and white flowers, bees choose the higher-calorie reward. Certain color-pairs elicit energy maximization instead of constancy. We asked if honeybees abandon color-constancy when handling time of one morph significantly increases. An artificial flower patch of the Wells et al. design used pedicellate 30x30mm Plexiglas squares with a 3mm-deep nectary for 'shallow' flowers, and a 1.5ml centrifuge tube inserted into a similar Plexiglas square for 'deep' flowers. Each style was painted with blue, yellow or white Testor's paints. Blue and yellow 'deep' flowers provisioned with 4ul 1M sucrose were organized in a grid of 36. Free-flying marked bees were observed foraging, and then yellow flowers of the 'shallow' design were substituted, followed by blue flowers of the 'shallow' design, in sequence. A second experiment used a blue/white dichotomy. A third offered a greater reward in the deep-welled blue or yellow flowers. Increased handling time does influence the degree of colour constancy. (Session 30: Foraging III; Tues. 4:30-4:50pm; Gallery)
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194 RECOGNITION OF GROUP MEMBERSHIP BY VOICE IN MEXICAN JAYS
*Steven L. Hopp1, Piotr L. Jablonski2 & Jerram L. Brown3
1Department of Ecology and Evolutionary Biology, University of Arizona, and Arizona-Sonora Desert Museum, Tucson, AZ 85721; 2Department of Neurobiology, University of Arizona, and Institute of Ecology, Polish Academy of Sciences, 05-092 Lomianki, Poland; 3Department of Biological Sciences, State University of New York, Albany, NY 12222 (shopp@u.arizona.edu)
Mexican Jays (Aphelocoma ultramarina) live in stable social groups of 5 to 25 individuals. Groups exhibit dominance hierarchies and defend territories against outsiders. We tested whether Mexican jays showed vocal recognition of group membership in a population of color-banded birds in southeastern Arizona. We conducted playback trials of loud calls recorded from either an identified group member or an individual from a nearby but noncontiguous group. Calls were played near established feeding stations during regular feeding sessions. By all measures used, the jays showed differential responding to inside and outside members of the group, with greater responding to outsiders. Thus, the loud calls of jays are used to recognize group membership, and perhaps individual identity. (Session 39: Communication VII; Weds. 2:10-2:30pm; Rooke)
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116 THE LATEST EFFECT OF PREDATORY FISH ON DRAGONFLY GROWTH AND SURVIVAL: AN EMPIRICAL PARADOX EXPLORED
Kevin R. Hopper1 & *Brad R. Dickey2
1Department of Biology, Indiana State University, Terre Haute Indiana; 2School of Biological Sciences, University of Kentucky, Lexington, KY 40506 (bdickey@ceeb.uky.edu)
The size attained at and probability of survival to maturation are two critical components of fitness, especially in organisms with complex life-cycles. These are often mediated through activity rates: the degree to which an organism forages for food and incurs predation risk. In two conflicting previous experiments, larvae of the species Epitheca cyanosura have been found to grow both faster and slower in the presence of fish predators versus in their absence. At low food levels, fish predation on dragonflies should lower larval density, increase per capita food availability, and allow surviving larvae to grow larger. We tested this hypothesis in an experiment with 4 levels of food where fish were either present or absent. Our results are in accordance with the hypothesis. Without predators larval survival was correlated with food level, but size was independent. With predators, larval survival was independent of food level, but size was correlated. We present a model to describe these results and explore the implications, particularly with respect to ovipositioning and life history evolution. (Session 23: Predator/Prey III; Tues. 10:30-10:50am; Rooke)
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Fellows Lecture Tues. 8:30am
Coleman Hall

Fellow: COURTSHIP PHEROMONES IN PLETHODONTID SALAMANDERS
Lynne D. Houck
Zoology Dept., Oregon State University, Corvallis, OR 97331 (houckl@ava.bcc.orst.edu)
I present an overview of behavioral experiments focused on variation in courtship success in terrestrial salamanders. An initial focus was on whether male courtship pheromones could elicit a measurable female response. We showed that these pheromones can increase female receptivity, thus increasing the probability that the female will be inseminated by the courting male. This demonstration led to the chemical analysis of extracts obtained from glands that produce courtship pheromones. Pheromone extracts were composed primarily of proteins, and subsequent behavioral experiments tested the effects of individual protein components. Recent results show that a single protein component of the male courtship pheromone is sufficient to affect female behavioral response. This is the first identification of a vertebrate pheromone component that alters female receptivity. This demonstration has led to further chemical analysis of the active protein, as well as a molecular investigation of the genetic evolution of pheromone components.
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P52 EFFECT OF SOCIAL ENVIRONMENT ON SEXUAL BEHAVIOR OF MALE GUPPIES
*Anne E. Houde & Kristie Soeder
Department of Biology, Lake Forest College, Lake Forest IL 60045 (houde@lfc.edu)
Numerous previous studies have documented plasticity in the courtship behavior of male guppies. Many of these have focused on the effects of predation regime or the presence of predators. We examined the effects of social environment, specifically sex ratio, on sexual behavior of male guppies. Males were observed in social groups with male-biased, female-biased or even sex ratios. Each male was observed three times, in groups consisting of six males plus three, six and 12 females. The frequency of courtship displays, competitive interactions with other males, and sneaky copulation attempts was recorded in 10-minute observation sessions. The frequency of competitive interactions was highest when only three females were present and lowest when 12 were present; these differences were statistically significant. Rates of courtship display differed among the three sex ratios but the differences were only marginally significant in preliminary analyses. There were no significant differences in the rate of sneaky copulation attempts. Thus, the availability of females can affect the relative rates of sexual and competitive behaviors of males. These differences in male behavior could affect the female s ability to choose and hence affect the evolutionary outcome of sexual selection. (General Posters; Sun. eve; Terrace)
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165 RE-EXPRESSION OF SONGS DELETED DURING DEVELOPMENT IN WHITE-CROWNED SPARROWS
Gerald E. Hough II
Department of EEOB, 1735 Neil Avenue, The Ohio State University, Columbus, OH 43210 (hough.14@osu.edu)
The white-crowned sparrow, Zonotrichia leucophrys, learns multiple song types as a juvenile but discards all but one by the end of the first singing season. This single sing type is maintained throughout adulthood. It is unknown what happens to these extra songs in subsequent years- are they discarded or can they be produced later in life? We measured the song output of 7 oriantha and 8 gambelii white-crowns across two singing seasons. Thirteen of fifteen birds sand deleted songs at the start of the second singing season. Although re-crystallization of the original song was seen in all individuals, the possibility exists for birds to change songs from year to year. The traditional dichotomy of closed-ended versus open-ended learning is inadequate for birds that learn early in life but can change their song output seasonally. We suggest a third category that includes species that have a closed sensitive period to material for subsequent production but retain the ability to recall deleted songs later in life. This type of learning, selective attrition followed by seasonal re-expression may be the method used by many of the currently considered open-ended learning species. (Session 33: Development I; Weds. 10:10-10:30am; Forum)
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P53 CONSPECIFIC BROOD PARASITISM IN THE HOUSE SPARROW
*Anne M. Houtman1, Catherine Fry2 & Jennifer Grindstaff3
1Department of Biology, Knox College, Galesburg, IL 61401; 2Department of Biology, University of Maryland Baltimore Park, Baltimore Park, MD ; 3Department of Biology, Indiana University, Bloomington, IN (ahoutman@knox.edu)
Our population of house sparrows has a very high proportion of young from extra-pair copulations (EPC; 36% of all young; 61% of nests) and from conspecific brood parasitism (CBP; 26% of young, in 50% of nests). The majority of these CBP chicks (21% of all chicks in which we had DNA for both of the putative parents) are unrelated to their putative mother, but related to their putative father. The general view of CBP is that a female sneaks into a nest while the parents are gone and lays an egg with no genetic material from either nest-owner. Our data suggest that males may be allowing females to dump eggs in exchange for an EPC. (General Posters; Sun. eve; Terrace)
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142 POTENTIAL RISK OF RELEASING A TRANSGENIC ORGANISM WHEN TRANSGENES AFFECT MATING SUCCESS: SEXUAL SELECTION AND THE TROJAN GENE HYPOTHESIS
*Richard D. Howard & W. M. Muir
Department of Biological Sciences, Purdue University, West Lafayette IN 47907 (rhoward@bilbo.bio.purdue.edu)
Interest in transgenic organisms is balanced by concern over ecological hazards such as species extinction if these organisms are released into nature. A necessary prerequisite for any ecological risk associated with the release of transgenic organisms is that the transgene can spread in natural populations when rare. This is usually assumed to be unlikely because transgenic organisms typically have some viability disadvantage. However, if transgenes also enhance male mating success this assumption may be incorrect. We examined the risk to a natural population after release of a few transgenic individuals when the transgenic trait simultaneously increased transgenic male mating success and lowered viability of transgenic offspring. We obtained relevant life history data using the fish, Japanese medaka (Oryzias latipes). Our model predicts that a transgene can spread when a few transgenic individuals are introduced into a natural population, as a result of enhanced mating advantage, but the reduced viability of offspring will cause eventual local extinction of both populations. (Session 28: Evolution and SS I; Tues. 2:30-2:50pm; Olin)
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212 THE ROLE OF DEVELOPMENT IN THE EVOLUTION OF VOCALIZATIONS: CALL NOTES IN BLACK-CAPPED, CAROLINA, AND MOUNTAIN CHICKADEES
*Melissa Hughes1, Steve A. Nowicki2, Jack Hailman3, Sarah Woolley2 & Bernie Lohr4
1Ecol. & Evol. Biol, Princeton University., Princeton, NJ 08544; 2Dept. of Zoology, Duke University., Durham, NC 27708; 3Dept. of Zoology, University of Wisconsin-Madison, WI 53706; 4Dept. of Psych., University of Maryland, College Park, MD 20742 (mhughes@Princeton.edu)
Developmental mechanisms can play a role in the evolution of morphological differences among species. The role of development in the evolution of species differences in behavior is less clear. The introductory call notes of the chick-a-dee call produced by the black-capped chickadee differ how they develop, with the development of B- and C-notes being more dependent on learning than the development of A-notes. When the call notes of black-capped, mountain and Carolina chickadees are compared in an acoustic space defined by 14 acoustic variables, we find that A-notes of all 3 species are tightly clustered, while B- and C-notes of different species are located in different regions of the acoustic space. Thus the notes which develop with greater dependence on learning appear to differ more among species than the note that depends less on learning for normal development. This analysis suggests that the evolution of call notes in chickadees is influenced by the degree to which learning is necessary for the development of normal note structure, and provides a basis for future studies of the relationship between the development and evolution of vocalizations. (Session 43: Communication VIII; Weds. 3:30-3:50pm; Rooke)
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137 REPRODUCTIVE SUCCESS AND HABITAT SELECTION IN COLONIAL BANK SWALLOWS (RIPARIA RIPARIA)
Sarah C. Huhta
600 S. College Avenue, University of Tulsa, Tulsa, OK 74104 (s_huhta@hotmail.com)
This study was designed to (1) Assess the reproductive success of Bank Swallows (Riparia riparia) living in twelve colonies ranging in size from 5 to 645 active nests; (2) Measure some of the possible costs of coloniality for this species; and (3) Quantify soil compactness at colonies of different sizes. Competition for nest sites was assessed when birds were excavating burrows by counting fights per nest per half hour. Data regarding clutch size, brood size, and survival of nestlings to day 13 was collected by frequent nest checks with a ripariascope. Fleas (Ceratophyllus styx riparius) were counted at burrow entrances during nest checks to quantify relative ectoparasite levels. Soil compactness was measured with a pocket penetrometer. Results showed that competition for nest sites as well as reproductive success increased significantly with the number of active nests per colony. Colony size increased with the compactness of the nesting substrate. The mean number of fleas per nestling per nest did not affect reproductive success. Patterns of increasing competition and reproductive success with colony size and soil compactness suggest that high quality nest sites may be a limited resource for Bank Swallows. (Session 27: Social behavior I; Tues. 2:30-2:50pm; Rooke)
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175 TERRITORY DEFENSE BY MALE AND FEMALE CAROLINA WRENS
Jeremy D. Hyman
Department of Biology, University of North Carolina, Chapel Hill, 27599-3280 (JHYMAN@EMAIL.UNC.edu)
In temperate songbirds, song and territory defense are primarily male activities, typically confined to the breeding season. Carolina wrens Thryothorus ludovicianus are typical among temperate birds in that only males sing, but are unusual in that they sing and are territorial year-round. In tropical members of this genus, both sexes sing and defend territories year-round and female song is thought to function in territorial defense against other females. Female Carolina wrens, though lacking complex song, have sex specific calls. I performed playbacks of male song, male calls, and female calls to territorial pairs to test whether these vocalizations elicit different responses in males and females. Males responded strongly to all playback treatments. Male response to male songs and calls indicate that both vocalizations are sufficient to elicit intrasexual territorial defense. Male response to female calls might indicate intersexual territory defense or attraction to potential mates. Females responded equally to male songs and calls, but more strongly to female calls. These results indicate that female vocalizations function in intrasexual territorial defense. (Session 35: Communication VI; Weds. 10:30-10:50am; Rooke)
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P54 DENSITY DEPENDENCE AND FREQUENCY DEPENDENCE OF ALTERNATIVE ANTI-PREDATOR STRATEGIES BY A WHIRLIGIG BEETLE, DINEUTUS AMERICANUS
*Alastair J. Inman & Anne M. Houtman
Department of Biology, Knox College, Galesburg, IL 61401 (ainman@knox.edu)
Whirligig beetles exhibit alternative strategies when threatened by predators: diving underwater or skating on the surface. Individual whirligigs vary significantly in their propensity to dive or skate when threatened. Whether an individual dives or skates in the presence of a predator also depends upon the number of whirligigs in the group: whirligigs in larger groups are more likely to skate than dive (density dependence). Furthermore, individuals are more likely to dive in a group of dive prone whirligigs and more likely to skate in a group of skate prone whirligigs (positive frequency dependence). Individuals also spend more time diving as the intensity of the threatening stimulus was increased. These results are discussed in terms of the costs and benefits of anti-predatory behaviour. (General Posters; Sun. eve; Terrace)
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140 DIRECT, FISHERIAN AND GOOD GENES BENEFITS FROM FEMALE CHOICE IN AN ARCTIID MOTH (UTETHEISA ORNATRIX)
*Vikram K. Iyengar & Thomas K. Eisner
Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 (vki1@cornell.edu)
The arctiid moth Utetheisa ornatrix shows a sexual size dimorphism that is unusual among lepidopterans: males are larger than females. This dimorphism may have arisen through sexual selection, as females preferentially mate with larger males. Many factors may be responsible for this female preference. First, we determined that size is heritable, which suggested that females may choose large males to obtain genetic benefits for their offspring. Comparing the offspring of sisters mated to different-sized males, we found that sons of large males had greater mating success and daughters of large males had higher fecundity than the offspring of small males. Second, females may prefer larger males because they provide more direct benefits for their offspring. We show that females mating with larger males also receive more nutrients and pyrrolizidine alkaloids, defensive chemicals that provide her and her eggs with better protection from predators. These results demonstrate that Utetheisa females simultaneously receive direct phenotypic and indirect genetic benefits through mate choice based on male size. (Session 28: Evolution and SS I; Tues. 1:50-2:10pm; Olin)
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151 DIET AND COLORATION IN FEMALE CONVICT CICHLIDS (CICHLASOMA NIGROFASCIATUM)
*J. Kasi Jackson, Tiffany K. Lloyd & Aaron L. Brown
CEEB, 101 Morgan Building, University of Kentucky, Lexington, KY 40506-0225 (kasi@ceeb.uky.edu)
Many sexual selection models discuss male ornamentation. Female traits are less well understood. In convict cichlids, Central American stream-dwelling fishes, females are more colorful than males. Convicts form pairs to care for young for 8 weeks. Before pair formation, females develop orange flecks along their ventral surfaces. These females court males and display aggressively toward other colorful females. Fish use dietary carotenoid pigments to produce orange coloration. One hypothesis for such coloration is that it signals foraging ability and resultant physical condition to potential mates. The relationship between diet and coloration was examined in a laboratory experiment using 64 female convict cichlids housed separately. The fish were divided into 4 groups and fed one of 4 diets for 4 months: good or poor quality food with and without carotenoids. Every 6 to 8 weeks, data were collected on the fish's weights, lengths, spectral reflectance and number of flecks. The relationships between diet and coloration (fleck number and reflectance) or diet and condition (weight, controlled for length) were determined using ANCOVA. Diet quality had a significant effect on condition. Carotenoid content had a significant effect on fleck number (p<0. 01). (Session 30: Foraging III; Tues. 4:50-5:10pm; Gallery)
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153 INDIVIDUAL DECISIONS AND GROUP DYNAMICS IN PHOLCID SPIDERS
Elizabeth M. Jakob
Department of Entomology, University of Massachusetts, Amherst, MA 01003 (ejakob@ent.umass.edu)
Individual variation in the costs and benefits of group living may drive the dynamics of group formation and maintenance. The spider Holocnemus pluchei is facultatively web-sharing: individuals may join groups or construct energetically expensive webs. I conducted field experiments to investigate how these decisions are affected by a spider s size and recent feeding success. Small and medium spiders were more likely than large spiders to be excluded from group webs. However, small and medium spiders were also the most frequent colonists of webs from which the occupants had been experimentally removed, indicating that webs are valuable resources. Small and medium spiders were also the most frequent builders of webs in areas from which webs had been cleared; large spiders rarely built new webs. These web-builders also had significantly smaller condition indices than the population at large, suggesting that investing in a web may be a last-ditch strategy followed by spiders under energetic stress. Thus, the pattern of grouping we see in the field results from two factors: the striking ontogenetic differences in the decisions that spiders make, and conspecific interactions that constrain spider choices. (Session 31: Social behavior II; Tues. 3:30-3:50pm; Rooke)
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38 PARENTAL CARE AND MALE DESERTION IN A CICHLID FISH
*Michael D. Jennions1, Steven R. Telford1 & Manuel J. Velez2
1Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Republic of Panama; 2Department of Zoology,University of Florida, Gainesville (gam128@gamboa.si.edu)
A recent phylogeny of the cichlids suggests that female-only care usually evolves from biparental care. Studies of species in which both female-only and biparental care occur may therefore shed light on the factors that promote this evolutionary transition. The Central American cichlid (Aequidens coeruleopunctatus) is a substrate spawner. It exhibits biparental care, with both parents defending the free-swimming fry against potential brood predators. There are, however, differences among breeding pairs in the extent of male parental care because male desertion prior to brood independence sometimes occurs. There is considerable variation both within and among populations in the timing of male desertion. We provide a description of sex differences in parental care, and the effect of male desertion on female parental care behaviours. We then consider those factors that are potentially responsible for variation in the timing of male desertion. These factors include: the opportunity to remate, the density of potential brood predators, the stage of development of the fry and brood size. (Session 8: Parental Care II; Sun. 4:30pm; Gallery)
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P10 OFFSPRING OF THE SLAVE-MAKER ANT, P. BREVICEPS AND OF ITS FORMICA HOST SPECIES: DO HETEROSPECIFICS REAR THEM UNCONDITIONALLY?
*C. A. Johnson1 & R. K. VanderMeer2
1Department of Psychology, Graduate School & University Center of City University of NY, Hunter College, NY 10024; 2USDA/ARS, CMAVE, Gainesville, FL 32608 (cjohnson@amnh.org)
Colonies of the slave-making ant, Polyergus breviceps, are conceived with the adoption of the parasite queen and her eggs by adult Formica. To determine whether host workers adopt parasite eggs because parasite and host retain chemical characteristics of their common ancestor, we presented eggs of conspecific and heterospecific Formica and of P. breviceps to two species of host Formica, and recorded the number reared to adulthood. Pupae were similarly presented to determine if immatures at a later developmental stage induce like responses from workers. Cuticular hydrocarbon profiles were compared. Workers did not readily adopt heterospecific eggs and pupae, even if congeneric. Hydrocarbon profiles of egg and pupae are distinguishable, although there is conservation of pupal hydrocarbon components between species. This discrepancy between behaviors exhibited and chemical profiles suggests hydrocarbons may not be involved in recognition of immatures. Adoption of parasite offspring may involve time-linked modification of worker recognition templates through continual interactions with the parasite queen. (Founders Award poster; Sun. eve; Terrace)
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166 YOUNG CAPUCHINS DO NOT ALTER AFFILIATIONS STRATEGICALLY DURING FORAGING CHALLENGES
*Elizabeth C. Johnson, Dorothee M. Fragaszy, Elizabeth Dettmer, Alexander Skolnick, Julie Johnson-Pynn & Jay Silverman
Department of Psychology, University of Georgia, Athens, GA 30602 (johnsone@egon.psy.uga.edu)
This study investigated the features of a primate social system and of individual behavior which might support social learning. Data on social and feeding behavior were collected in two groups of capuchin monkeys Cebus apella during baseline conditions and when three extractive feeding tasks were introduced into the groups' cages. The test conditions presented young animals with an opportunity to benefit from remaining near particular others at the extractive food sites. Data from eight juveniles (< 2 years) were analyzed for evidence of opportunistic affiliation with proficient adults during the test conditions. Affiliation scores between juveniles and adults increased in the experimental conditions. However, juveniles investigated food sources more often while alone than with another, and did not shift their affiliation preferences in the test conditions compared to baseline. Both of these findings indicate that the young capuchins did not alter their behavior in a way that would specifically enhance social learning from proficient adults during a difficult food-gathering task. (Session 33: Development I; Weds. 10:30-10:50am; Forum)
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P9 BUGLE CALLS OF ROCKY MOUNTAIN ELK AND INDIVIDUAL SIGNATURE CHARACTERISTICS
*J. A. Johnson & J. A. Clarke
Biological Sciences Department, University of Northern Colorado, Greeley, CO 80639 (Delphi875@aol.com)
Primary goals of this study were to quantitatively describe bugle calls of male Rocky Mountain elk Cervus elaphus nelsoni during the breeding season and determine if individual bulls could be identified based on signature characteristics of bugles. Bugle calls were recorded in Rocky Mountain National Park (September-October 1998) using a Uher recorder and Sennheiser microphone. Recorded calls were analyzed with the CANARY sound analysis program. Preliminary analyses of 54 calls from seven bulls revealed: 1) duration mean=2.81s, 2) change in frequency mean=4.06 kHz, 3) maximum frequency of dominant resonances mean=4.62 kHz and 4) minimum frequency of dominant resonances mean=0.56 kHz. Analyses indicate that bulls exhibit unique signature characteristics in the peak frequencies of whistles' dominant resonances (p<0.01, all cases). Also, the rate of change in frequency from on-glide onset to dominant whistle and from dominant whistle to off-glide end exhibit individual differences. Data will be used in further studies to determine if relationships exist between call characteristics and bull size/age and herd size as female elk may use bugle characteristics as cues in mate choice. (Founders Award poster; Sun. eve; Terrace)
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P55 THE EFFECT OF MOLT ON SPRING DEPARTURE DATE IN WHITE-THROATED SPARROWS
*Karen M. Johnson & Daniel A. Cristol
Department of Biology, College of William & Mary, Williamsburg, VA 23187 (kmjohn@maila.wm.edu)
Migratory birds could enhance their reproductive success by returning quickly to breeding grounds, however little is known about what mechanisms determine when a bird is able to leave its wintering area. We examined one potential mechanism, the relationship between molt and migration, to determine if molt acts as a constraint on departure. By increasing daylength, we induced early molt, relative to control and free-living birds, in 42 white-throated sparrows. After releasing these birds and their controls, we determined date of departure. By comparing date of departure between treatments, we tested the prediction that birds that molted earlier began spring migration earlier. The impact of wintering ground dynamics on migration timing is poorly understood and this study improves our understanding of the roles of dominance status and molt on spring departure. (General Posters; Sun. eve; Terrace)
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36 BENEFITS OF DELAYED DISPERSAL IN A SEMI-NATURAL POPULATION OF A SUB-SOCIAL SPIDER
*Thomas C. Jones & Patricia G. Parker
Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH 43210 (jones.874@osu.edu)
In the Theridiid spider Anelosimus studiosus, most juveniles remain in their natal web with their mothers, forming temporary colonies in which individuals cooperate in web maintenance and prey capture. Juveniles typically disperse at maturity, though subadult singletons can build webs and continue to develop. To explore costs and benefits of delayed dispersal, fourth instar juveniles were removed from semi-natural colonies and forced to build their own webs, while in control colonies, juveniles were removed then replaced. Mothers in control colonies produced second broods more quickly, remained in their webs longer, and, of those found dead, survived longer than mothers in removal colonies. Colonial juveniles had higher survivorship and obtained more prey than singletons. Within control colonies, total prey capture positively correlated with both the number and age of the juveniles; however, the prey captured per juvenile showed no effect of colony size. There was no effect of colony size or age on variance in prey capture. These data suggest that delayed dispersal enhances both juvenile survival and the mother's future reproductive success. (Session 8: Parental Care II; Sun. 3:50pm; Gallery)
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65 THE ROLE OF ULTRAVIOLET RADIATION IN BODY COLORATION AND MATE CHOICE OF LAKE MALAWI CICHLIDS
*R. C. Jordan1, K. A. Kellogg1, F. Juanes2, J. R. Stauffer3 & E. R. Loew4
1Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01375; 2Department of Forestry and Wildlife Management, University of Massachusetts, Amherst, MA 01375; 3School of Forest Resources, The Pennslyvania State University, Unversity Park, Pennslyvania 16802; 4Division of Biological Sciences, Veterinary Research, Cornell University, Ithaca, New York 14853 (rcjordan@cas.umass.edu)
Sexual selection through female choice has often been proposed as a mechanism of speciation within the cichlid fishes of the East African Lakes. Mate preference cues are thought to be primarily visual because of the great diversity of male body coloration and cichlids' ability to discriminate color differences. Also, it has recently been shown that many cichlids have the capability to detect ultraviolet light. The role of ultraviolet radiation in female choice, however, has not yet been considered in cichlids. The objective of this study was to quantify body coloration extending into ultraviolet wavelengths, and the role that ultraviolet radiation may have in intraspecific mate choice within a group of Lake Malawi rock-dwelling cichlids. Body coloration over the entire visible spectrum was measured at six patches form both males and females using a spectrometer for three species Metriaclima zebra, M. benetos, and M. barlowi. Intraspecific mate choice trials were also conducted. Females were given a choice of two males: one displayed in an ultraviolet enriched and one in an ultraviolet blocking environment. We found that all three species were ultraviolet reflective and show little intraspecific differences in coloration at similar body patches. Results from the mate choice trials were variable. (Session 12: Sexual selection II; Mon. 11:10-11:30am; Olin)
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136 FITNESS CONSEQUENCES OF COOPERATIVE COLONY FOUNDING IN THE DESERT LEAF-CUTTER ANT, ACROMYRMEX VERSICOLOR
*Glennis E. Julian & Sara E. Cahan
Department of Biology, Arizona State University, Tempe, AZ 85287-1501 (glennis@asu.edu)
The evolution of cooperative colony founding in ants has been attributed to conversion of extra resources into increased colony growth rate or competitive ability. However, the extent and type of individual investment into group colonies is not well understood. We investigated the effects of cooperation in the desert leaf-cutter ant (Acromyrmex versicolor) on colony growth, foraging activity and colony survival. To do this, we collected newly mated foundresses from the field and started colonies in the lab with either a single foundress or three foundresses. We found that colonies founded by a single foundress showed similar growth rates and foraging patterns as those containing three foundresses over 12 weeks. However, single foundresses were significantly less likely to initiate a successful symbiotic fungus garden, which led to colony starvation and death. This suggests that cooperation in this species is more likely maintained by survival benefits than by growth rate differences, which may be constrained in groups by individual and colony level costs. (Session 27: Social behavior I; Tues. 2:10-2:30pm; Rooke)
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P56 COUNTERSHADING AND COMMUNICATION II: BEHAVIOR OF COUNTERSHADED SONGBIRDS AT LOW SUN ANGLES
*Michael J. Justice, Kimberly Joyner, Jillian M. Lombardo, Renee R. Porr & Jamie B. Witt
Department of Biology, Chowan College, Murfreesboro, NC 27855 (justim@chowan.edu)
Countershading (dark dorsum/light ventrum) is often explained as an antipredator adaptation because it will produce crypsis via self-shadow concealment when the animal is illuminated from above. However, recent research has shown that some countershaded songbirds tend to face their ventra toward the horizon sun, a conspicuous behavior because it illuminates their light ventra and shadows their dark dorsa. The present research used focal-animal sampling during low sun angles to investigate the consequences of sunward orientation on communication in Northern Mockingbirds and Eastern Bluebirds. Orientation with respect to the sun was recorded along with communicative behaviors such as vocalizations and interactions with other birds. Chi-squared analyses indicated that both species, when sunlit, spent significant time facing the sun. Interestingly, more communicative behaviors than expected occurred when the birds were oriented sideways with respect to the sun. These results suggest a relationship between communication and orientation of countershaded birds with respect to the sun, and the possible importance of a lateral line of contrast for this communication. (General Posters; Sun. eve; Terrace)
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P57 THE EFFECT OF MALE COLOR ON FEMALE MATE CHOICE IN CONVICT CICHLIDS (CICHLASOMA NIGROFASCIATUM)
*Teresa C. Justice & Jessica M. King
Department of Psychology, Chowan College, Murfreesboro, NC 27855 (justit@chowan.edu)
Prior studies have demonstrated an effect of male size on female mate choice in convict cichlids (Kennleyside et al. ; Noonan, 1983). However, previous studies with this species have not investigated the effect of male color on female mate choice. Weber and Weber (1976) found that males of this species prefer dark-striped females over white females. The dark-striped color pattern is the wild-type. The purpose of this study was to determine the effect of male color on the mating preferences of females. It was hypothesized that females would prefer a dark-striped male. To test this hypothesis, one dark-striped and one white male, matched for size, were used for preference tests with twenty females. The males were housed in individual tanks adjacent to a test tank. A female was placed into the test tank and her preference for a male was determined by observing the time she spent near each male and in a neutral zone. Nine females displayed a preference for the dark-striped male, eight preferred the white male, and three displayed no preference. The females did not display a preference for the dark-striped wild-type males using this type of preference testing. (General Posters; Sun. eve; Terrace)
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P58 DIRECT AND INDIRECT BENEFITS OF MALE PHENOTYPE IN THE GUPPY
*David Kabelik, F. Helen Rodd & Mart R. Gross
Department of Zoology, University of Toronto, 25 Harbord Street,Toronto, Ontario, M5S 3G5 Canada (kabelik@zoo.utoronto.ca)
Since a male s condition can influence his fertility, females choosing mates on the basis of condition dependent traits may be gaining directly by having a greater number of ova fertilised. If condition is inherited, and sperm production is related to condition, then females mating with high quality males will also gain indirectly. Direct benefits have been shown in guppies where display rate is related to sperm production (Matthews et al 1997). We here show that a male's body size, and the brightness of his orange spots, are directly related to his offspring production. Indirect benefits (good genes) in guppies were demonstrated by Reynolds and Gross (1992) who showed that large males produced faster growing offspring and daughters with greater reproductive output. We show that indirect benefits can also be gained through sons. Although we hypothesised that high quality males may also produce larger offspring, this claim was not supported. Thus, fertility leads to both direct and indirect benefits. (General Posters; Sun. eve; Terrace)
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42 UNEQUAL FITNESS PAYOFFS OF ALTERNATIVE MALE MATING BEHAVIORS IN THE WATER STRIDER LIMNOPORUS DISSORTIS
Susan M. Kain
Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 (smk10@cornell.edu)
Males of the water strider Limnoporus dissortis regularly switch between two mate-acquisition behaviors. When a male is territorial, he defends floating vegetation and mates with females that come to the vegetation to oviposit. When a male is wandering, he strides around the pond searching for and mating with females ovipositing at undefended vegetation or at vegetation defended by territorial males. To determine why alternative behaviors are maintained in L. dissortis, I investigated the relative fitness payoffs of territoriality and wandering. Territoriality yielded significantly higher mating success, clutch size, and fertilization success than wandering, but these benefits were partially offset by the higher daily mortality rate associated with territoriality. When simultaneously taking into account differences in all fitness components using a bootstrapping technique, the average payoff of territoriality was seven times higher than the average payoff of wandering. Because the alternative behaviors are maintained despite unequal fitness payoffs and because average fitness payoffs were unequal even for males of a similar length class, territoriality and wandering are alternative tactics in a conditional pure strategy. (Session 9: Allee Award session; Mon. 10:10am; Forum)
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93 EVIDENCE OF USE OF ECHOLOCATION CALLS FOR SEX RECOGNITION IN BIG BROWN BATS
*Karry A. Kazial & W. Mitchell Masters
Department of Evolution, Ecology, & Organismal Biology, The Ohio State University, Columbus, OH 43210 (kazial.1@osu.edu)
Previously it has been suggested that echolocation calls may be used in a communicative manner. Intraspecific variation in echolocation calls has been found for many species, but very few studies have examined whether bats pay attention to this information. We conducted playback experiments assessing the response of 15 female big brown bats, Eptesicus fuscus, to male and female echolocation calls. Bats received playback of 30 seconds of noise, 60 seconds of either male or female echolocation calls, and a final 30 seconds of noise. We measured the bat's vocalization rate during each playback period. Vocalization rate differed between playbacks of male and female echolocation calls (p=0.033) and during the final noise period (p=0.007). The female bats vocalized more often during (p=0.017) and after (p=0.003) male echolocation call playbacks. Female big brown bats responded differentially to echolocation calls based on the sex of the emitter, supporting the possibility that bats use echolocation calls in communication. (Session 18: Communication V; Mon. 3:50-4:10pm; Rooke)
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105 INTER-POPULATION COMPARISON OF MULTIPLE PATERNITY IN THE TRINIDADIAN GUPPY
*Clint D. Kelly & Jean-Guy J. Godin
Biology Department, Mount Allison University, Sackville, NB, E4L 1G7, Canada (cdklly@mta.ca)
Animals commonly modify their mating behaviour in response to increased risk of predation. If predation risk increases the relative frequency of sneaky copulations in males and reduces choosiness in females, as shown for some species, then we predict a higher frequency of concurrent multiple paternity per brood in females originating from high-predation populations as compared to females from low-predation populations. To test this hypothesis, genetic data from two polymorphic microsatellite loci were employed to conservatively estimate multiple paternity in 10 populations of the Trinidadian guppy Poecilia reticulata that have evolved under different fish predation regimes. Our data suggest that, on average, the frequency of concurrent multiple paternity is nearly three times greater in high-predation populations than in low-predation populations. These results further suggest that predation risk reduces the variance in male mating success and thus the opportunity for sexual selection within populations. (Session 20: Sexual selection IV; Mon. 4:30-4:50pm; Olin)
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P59 SOCIAL PLAY SIGNAL IN BOTTLENOSE DOLPHINS
Meghan E. Kennedy
Marine Mammal Department, Minnesota Zoological Gardens, Apple Valley MN 55124 (mekennedy@stkate.edu)
Social play behavior in bottlenose dolphins, although frequent, is rarely addressed in qualitative studies. Because of the superficial similarities of play to aggression in many vertebrate species, it can be difficult to define. Primates and canids appear to have specific play signals which are used during play-fights when ambiguous behaviors, such as bite attempts, are performed (for example, play-face in primates and play-bow in canines). Similar behaviors in delphinids have yet to be described. We analyzed video recordings of social interactions within a captive group of six Atlantic bottlenose dolphins at the Minnesota Zoological Gardens. The sequences show a correlation between melon-oriented behavior and bite attempts during play-fights; this correlation is absent in our video clips of fights. Our results suggest that melon-oriented behavior performs a function analogous to the play-bow in canid behavior. (General Posters; Sun. eve; Terrace)
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163 LIFETIME REPRODUCTIVE SUCCESS OF FEMALE CHIMPANZEES OF GOMBE STREAM NATIONAL PARK
Kathleen B. Kerr
Georgetown Family Center, 4400 MacArthur Blvd., NW, #103, Washington, DC 20007 (research@georgetownfamilycenter.org)
Evaluating lifetime reproductive success is important to evolutionary theory and the author's interest in multi-generational family functioning. Bowen family systems theory stimulated this investigation of whether patterns observed in human families could be seen in chimpanzee families. Data was accumulated from the Gombe archives at U. of Minnesota on 16 females with accurate records of their entire reproductive careers. Descriptive statistics showed wide variation around means. The mean number of offspring living over age 13 was 1.5, less than the number required for replacement. Using the number of offspring surviving to a minimum age of possible reproduction (13 yrs.) as a criterion of success, no significant correlations or non-parametric tests of group differences for rank or age at first conception were found. Rank was based on the work of Pusey and Williams, using pant-grunts at meetings of females. Survival analysis of all births with accurate information who could have survived to ages 13 and 20 also showed no significant effect of mother's rank. Further work using other characteristics of the mother derived from family theory will be done. (Session 32: Evolution and SS II; Tues. 4:50-5:10pm; Olin)
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P60 TEMPERATURE-DEPENDENT MATERNAL AND PATERNAL INVESTMENT IN TWO HETEROPTERAN SPECIES
*S. L. Kight, M. Batino, J. J. Cseke & Z. Zhang
Department of Biology and Molecular Biology, Montclair State University, Upper Montclair, NJ 07043 (kight@pegasus.montclair.edu)
We examined the effects of ambient temperature on the brooding behavior of male waterbugs, Belostoma flumineum Say (Heteroptera: Belostomatidae) and female Sehirus cinctus (Heteroptera: Cydnidae). Because embryogenesis and breeding season are both associated with ambient temperature, parental individuals in warmer environments may be predicted to respond differently than those in cooler conditions. Completely-encumbered male Belostoma rarely terminate care early, regardless of ambient temperature, whereas partially-encumbered males housed under warm ambient temperatures are significantly more likely to discard unhatched eggs than males housed under cooler conditions. Female Sehirus housed in warmer temperatures also terminate care earlier than females at cooler temperatures. These results are discussed in the context of life history differences between the two species. (General Posters; Sun. eve; Terrace)
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143 INTROGRESSIVE HYBRIDIZATION IN PUPFISH: THE ROLE OF SEXUAL SELECTION
*A. Kodric-Brown & J. Rosenfield
Department of Biology, University of New Mexico, Albuquerque, NM 87131 (kodric@unm.edu)
Little is known about the role of sexual selection in introgression of closely related lineages. Hybridization between an endemic pupfish (Cyprinodon pecosensis) and an introduced congener (Cyprinodon variegatus) in the Pecos River provides an opportunity to study this process of lineage coalescence. We present preliminary results of experiments testing the visual and mating preferences of C. pecosensis and C. variegatus females for conspecific and heterospecific males. We also quantify agonistic interactions and territorial establishment of males of the two species to estimate their competitive ability. Both the mate choice and the male-male interaction experiments indicate that C. variegatus males are competitively superior to C. pecosensis males: they win agonistic encounters, obtain most matings, and are visually preferred by females. Our results suggest that sexual selection, both through male-male interactions and female choice, is an important process favoring the rapid spread of hybrids throughout the historic range of C. pecosensis. (Session 28: Evolution and SS I; Tues. 2:50-3:10pm; Olin)
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43 MATE PREFERENCE BASED ON SMALL KINSHIP DIFFERENCES PREDICTED REPRODUCTIVE SUCCESS OF MONOGAMOUS MALE OLDFIELD MICE
Karen Koeninger Ryan
Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637 (kmkoenin@midway.uchicago.edu)
Male oldfield mice, (Peromyscus polionotus rhoadsi), discriminated between unfamiliar, distantly related females according to an average 1.3% difference in their kinship to these potential mates. They preferred less related females. Previous theoretical and empirical studies have not addressed such small kinship differences, implicitly assuming them inadequate to drive the evolution of mate choice, particularly by males. However even a small incremental difference in mate quality may significantly affect male reproductive success, especially for monogamous species or those requiring maternal care. Indeed, this study demonstrates that such fine-scale discrimination between potential mates predicted the individual reproductive success of these monogamous males. Males paired with the female they preferred sired more offspring than males paired with the female they rejected. (Session 9: Allee Award session; Mon. 10:30am; Forum)
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P61 PRELIMINARY DATA ON THE SOCIAL BEHAVIOR OF WILD WHITE-FACED CAPUCHINS
*M. Kogut1, C. Solak1, N. Macker2 & M. Costello2
1Department of Biomedical Sciences, Grand Valley State University, Allendale, MI 49401; 2Department of Psychology, Grand Valley State University, Allendale, MI 49401 (costellm@gvsu.edu)
Data on the social behavior of wild white-faced capuchins (Cebus capucinus) were collected during the early dry season of 1997 and 1998 at the Curu Wildlife Refuge, Nicoya Peninsula, Costa Rica. Grooming, proximity, and activity budget data were collected using instantaneous sampling at thirty second intervals. Consistent with prior reports of social behavior in C.capucinus (e.g., Fedigan, 1993; Perry, 1996), adult females initiated and received more allogrooming than any other age/sex class. Adult females were also more likely than adult males or juveniles to be observed in close proximity (1m or less) to another individual. Juveniles engaged in more travel and play than adults. As measured by percent observations in physical contact with another, adult females with infants elicited the most interest from other troop members and were consistently and disproportionately observed at higher levels of the canopy. By almost all measures of sociality, these data suggest that adult females represent the social core of the troop. (General Posters; Sun. eve; Terrace)
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P62 THE USE OF OLFACTORY CUES BY GREEN AND BLACK POISON FROGS
*Robert Korbeck & Scott P. McRobert
Department of Biology, Saint Joseph's University, Philadelphia, PA 19131 (smcrober@sju.edu)
Olfactory cues are important sensory cues for many anurans, mediating their ability to recognize conspecifics, kin, sources of food and water, and home territory. We investigated the ability of the green and black poison frog, Dendrobates auratus, to utilize olfactory cues in the recognition of habitat components, home tanks, and tanks containing conspecifics, under laboratory conditions. During each assay, humidified air from two different aquaria was drawn through a glass Y-tube attached to a Plexiglas chamber holding an individual frog. The frog was allowed to move through the glass tube, choosing an arm associated with a particular stream of air. Our results show that D. auratus individuals were attracted to air drawn from aquaria containing habitat components (plants, etc) over air from empty aquaria. In addition, frogs were attracted to air from their own aquarium over air from aquaria containing habitat components, and over air from aquaria that had held other frogs. These results indicate that the behavior of D. auratus is affected by olfactory cues, and that these cues may be important in locating components of their habitat, other frogs, and home ranges. Applications of these data to the behavior of frogs in nature will be discussed. (General Posters; Sun. eve; Terrace)
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P63 MALE MATE CHOICE IN A MONOGAMOUS FISH, ARCHOCENTRUS SEPTEMFASCIATUM
*Tara B. Koutrouby & Matthew J. Draud
Department of Biology, C. W. Post, Long Island University, Brookville, NY 11548 (tkoutrou@titan.liu.edu)
I studied male mate choice and pair formation in the monogamous cichlid, (Archocentrus septemfaciatum). I designed experiments to test whether recent female reproductive activity influenced male mate choice. I hypothesized that males would prefer to mate with females who had not spawned recently. I assumed that these females would produce a viable egg clutch sooner than females who had recently spawned. I introduced two approximately equal sized females (less than 6% difference in volume) into a 10 gallon aquarium with one slightly larger male. One of the two females had recently spawned (within 6-48 hours) and the other had not spawned in at least 30 days. Males were allowed up to one month to select a mate and to spawn, although most males paired within a few hours and spawned within two weeks. A significant portion of males (78%) chose to pair and spawn with the recently spawned female. Although it is possible to interpret these results as male mate preference, behavioral observations suggest a strong female role in pair formation. I suggest that in this experiment, strong intrasexual female competition decreased the importance of male mate choice(General Posters; Sun. eve; Terrace)
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130 PLASTICITY OF CHEMORECEPTIVE RESPONSES TO PREY ODORS IN GARTER SNAKES (THAMNOPHIS SIRTALIS) REARED ON DIFFERENT DIETS.
*Mark A. Krause & Gordon M. Burghardt
Department of Psychology, University of Tennessee, Knoxville, TN 37996 (mkrause@utk.edu)
Thamnophis sirtalis is geographically widespread, due in part to its broad dietary habits. However, prior to feeding experience, the probability that individual snakes will attack certain prey stimuli may be biased toward a particular prey type. With feeding experience, these biases typically shift in the direction toward familiar prey odors. Here we examine the effects of diet and odor concentration on the chemoreceptive responses of (T. sirtalis) offspring born to mothers from two different habitats. Snakes were assigned to three diet conditions: fish (n=16), worms (n=20), and combined diets (n=18). Responses to serially diluted concentrations of fish and worm extracts were measured for each snake prior to feeding experience, and two more times at 10 week intervals. Diets for the snakes feeding on single prey types were then reversed and a fourth test was subsequently conducted. Results show that feeding experience affects chemoreceptive responses of garter snakes from varied habitats, and that discrimination between odor concentrations is dependent upon diet. (Session 26: Mechanisms II; Tues. 1:50-2:10pm; Gallery)
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3 CHEMICAL COMMUNICATION IN LIOLAEMUS TENUIS (TROPIDURIDAE)
*Anrtonieta Labra, Carlos A. Escobar & Hermann M. Niemeyer
Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile (alabra@abello.dic.uchile.cl)
Tests were conducted to determine whether both sexes of L. tenuis show intraspecific chemical recognition during breeding and post-reproductive seasons. In both seasons, both sexes produced fewer tongue flicks in their own enclosures than in any other one, suggesting self-recognition. Conspecific recognition was season dependent. During the post-reproductive season, lizards tongue-flick at similar rates in any extraneous enclosures, while during the breeding season, enclosures of females elicited more tongue flicks in both sexes. Overall tongue-flicking rates were higher during the reproductive season. To investigate the sources of semiochemicals in L. tenuis, feces of both sexes, and precloacal pore secretions (PPS) were studied. Feces were involved in self-recognition. Both sexes were recognized through their feces, and males through PPS. However, males were unable to distinguish their own PPS from those of other males. Results are discussed within the context of the social system of the species. Funding: Presidential Chair in Sciences awarded to HM. (Session 1: Communication I; Sun. 2:30pm; Forum)
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215 SINGING, SYMMETRY, AND AMBIDEXTERITY IN THE KATYDID CYPHODERRIS MONSTROSA (ORTHOPTERA: HAGLIDAE)
*Joshua Ladau & Andrew C. Mason
Neurobiology and Behavior, Mudd Hall, Cornell University, Ithaca, NY 14853 (jl172@cornell.edu)
Most Tettigonioidea (katydids) possess one functional file and one functional plectrum on opposite forewings, forcing them to sing with their left wing overlapping their right wing. One of the few exceptions to this rule is Cyphoderris monstrosa (Orthoptera: Haglidae), katydids that possess functionally symmetrical wings, allowing them to sing with either wing overlapping the other. We hypothesized that this ambidexterity slows how quickly singing organs deteriorate with use. Our hypothesis predicts (1) that C. monstrosa with more symmetrical wings should switch overlap more often than those with asymmetrical wings and (2) that the latter individuals should avoid their bad side. Consistent with this prediction, we found that symmetry positively correlates with switch rate (N=66). To manipulate symmetry, we then shaved one, both, or no plectra of 35 captive C. monstrosa. Artificially asymmetrical individuals switched overlap so as to sing with their unshaved plectrum and then ceased switching. Those with both plectra shaved switched overlap more often than control or asymmetrical katydids, but preferred neither wing. Like the correlation, these findings suggest that C. monstrosa switch overlap to optimize their song. (Session 43: Communication VIII; Weds. 4:30-4:50pm; Rooke)
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31 INTERSPECIFIC DIFFERENCES IN FORAGING, CACHING AND PILFERAGE IN SYMPATRIC HETEROMYID RODENTS: FIELD EVIDENCE FOR BEHAVIOURAL SPECIALIZATION
Lisa A. Leaver
Department of Psychology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada (leaverl@mcmaster.ca)
A number of hypotheses about species coexistence in heteromyid rodents have been suggested, but they have largely been tested in laboratory experiments which tend to focus on one potential avenue of resource partitioning. In this study I compile field observations and experiments that elucidate a number of behavioural differences between kangaroo rats and pocket mice in a Sonoran desert community. I will present evidence which indicates that the smaller sized pocket mice are better able to protect cached seeds from pilferage than the larger bodied Dipodomys merriami, while the latter species is better able to monopolize foraging at seed patches. Comparisons of (1) seed patch utilization, (2) seed caching and (3) vulnerability to pilferage between kangaroo rats and pocket mice highlight interesting differences between these two genera of rodents. Findings imply that behavioural specialization might be sufficient to explain coexistence in this community by preventing either the kangaroo rats of the pocket mice from completely monopolizing a resource. (Session 7: Foraging II; Sun. 3:50pm; Olin)
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P11 MOTIVATION TESTING OF PMU HOUSED MARES - IS THERE A WELFARE ISSUE?
*Joyce Y. Lee & Katherine A. Houpt
Department of Biomedical Sciences, School of Veterinary Medicine, Cornell University, Ithaca, NY 14853 (jyl13@cornell.edu)
The pregnant mare urine (PMU) industry receives criticism concerning the six month confinement of mares in straight stalls. A question to ask the horse would be whether they have a preference to remain in the stall, or would they prefer something else (ie pasture). We are, in essence, asking mares, through motivation testing, their preference for three treatments - (1) food, (2) exercise, and (3) companionship with another horse. By operant conditioning the horses, they are able to press a panel that is set at a steadily increasing interval per day, and release themselves from the straight stall if they achieve the specified number of presses for one of the above rewards. So far, we have found that the horses rank food > exercise > companionship in this order. With exercise and companionship being elastic demands, we will be comparing the results against food, an inelastic demand, to see how hard the horses will work for release. The data thus far shows that PMU conditions are not as stressful as previously thought; the horses are not working hard for excercise or companionship (Founders Award poster; Sun. eve; Terrace)
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24 THE RESPONSE OF MALE MEADOW VOLES TO SCENT MARKS OF FEMALE CONSPECIFICS IN DIFFERENT REPRODUTIVE STATES
*Danielle N. Lee & Michael H. Ferkin
Department of Ecology and Organismal Biology, University of Memphis, Memphis, TN 38152 (dnlee@memphis.edu)
Meadow voles, Microtus pennsylvanicus deposit feces, urine and anogenital scent marks to convey information about their reproductive state to conspecifics. We predict that the type of marks deposited by a vole and its frequency of scent marking is dependent on its reproductive state. We also predict that the type and frequency of a donor's scent mark affects the scent marking behavior of an opposite sex conspecific. We conducted two experiments t that addressed these predictions. In experiment 1, we hypothesized that postpartum estrus female (PPE) voles deposit more scent marks than non-PPE females (NR females). In experiment 2, we hypothesized that males investigating areas scented by either a PPE female or a NR female deposit more over-marks and adjacent marks on the marks of PPE females than on those of NR females. The data from experiments 1 and 2 supported each of these hypotheses, suggesting that PPE females signal their heightened attractivity to conspecifics and that males respond to scent marks of PPE females more than they do to those of NR females. Each scent marking may be involved in mate choice. (Session 5: Communication II; Sun. 4:50pm; Forum)
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51 THE SONG OF THE NIGHTINGALE WREN: PATTERNS IN A DIFFICULT SONG
Daniel W. Leger
Dept. of Psychology, Univ. of Nebraska, Lincoln, NE 68588-0308 (dleger@unl.edu)
The song of the nightingale wren, Microcerculus philomela, consists of a series of short, whistled notes that can go on for minutes without pause, and which seem to be random in frequency. Recordings made in Costa Rica were digitized and the frequency of each note was measured. A frame-shifting correlational technique was used to identify recurring patterns of note frequencies. Two birds recorded in 1998 had 21-note songs that were virtually identical. One also had a 32-note song and the other had a 33-note song. Recordings made in the same area in 1981 revealed an 18-note song type and a 33-note song type that were extremely similar to the 1998 recordings. All birds frequently terminated songs prematurely and had very short inter-song intervals, leading to the impression of long, rambling songs. (Session 10: Communication III; Mon. 11:10-11:30am; Rooke)
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182 THE EFFECTS OF NEIGHBORS VERSUS STRANGERS ON MALE-FEMALE INTERACTIONS IN SHEEPSHEAD MINNOWS
*J. K. Leiser & M. Itzkowitz
Department of Biological Sciences, Lehigh University, Bethlehem PA 18015 (jkl4@lehigh.edu)
Although dear-enemy recognition is a presumed cost-reducing mechanism in territorial species, little has been done to illustrate the benefits of a resident's being faced with neighbors compared to strangers. Using sheepshead minnows (Cyprinodon variegatus) competing in aquaria, we examined the effects of the presence of a familiar versus an unfamiliar conspecific on the interactions between a territorial male resident and a female introduced into his territory. While the presence of the female instigated greater aggression between the males compared to situations with no female, having a neighbor rather than a stranger freed the resident to spend more time courting the female. Although we did not see the reduction in aggression between neighbors consistent with the classical definition of dear-enemy recognition, the presence of a familiar neighbor rather than a stranger was reproductively beneficial to a resident male. (Session 36: Sexual selection VI; Weds. 11:10-11:30am; Olin)
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P64 LIZARD SELECTS HIGHER VALUE PREY FIRST
Allen R. Lewis
Department of Biology, University of Puerto Rico, Mayaguez, PR 00681-9012 (alewis@stahl.upr.clu.edu)
We tested the hypothesis that the teiid lizard Ameiva exsul selects higher value prey first. Lizards were housed in social groupings in six 50 m2 outdoor enclosures. We presented prey items in pairs in the feeder in each enclosure and scored 1) which prey item was taken first and 2) which lizard took it. Prey were larvae, pupae, and imagoes of the beetle Tenebrio molitor (mealworm), forms with which the lizards had prior experience. We tested four pairings: larva vs pupa, pupa vs imago, larva vs imago, and small larva vs large larva. Biochemical and calorimetric analyses of each developmental stage of the beetle permitted the ranking of prey by relative value: larva > pupa > imago. The high value of larvae resulted from relatively high fat content and low chitin content; the low value of imagoes resulted from high content of indigestible chitin. Lizards expressed statistically significant preferences: larva > imago, larva > pupa, pupa > imago, and large larva > small larva. Preferences we observed were consistent with optimal foraging models of prey selection. (General Posters; Sun. eve; Terrace)
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127 HOW TO GET YOUR ORGANISM INTO K-12 CLASSROOMS
*K. M. Lewis & M. M. Crowe
Department of Biology, Coastal Carolina University, Conway, S. C. 29528 (crowe@coastal.edu)
Teaching the general public about science and our own research is one of the most important goals of our work. Below we have outlined a procedure that anyone can follow to get their research into the hands of K-12 educators. The objectives of our project were to educate first, fourth and eighth grade students and educators about ghost crabs: their behavior, environment and role in the ecosystem. We accessed the local school district's WWW page and created lesson plans that correlated with their Science Achievement Standards. Our lesson plans stated the appropriate grade level, objectives, materials, prior preparation, detailed procedures, standards met by the lesson plan and links to other subjects. We then identified 3 educators and went to their classrooms. After teaching the students, who were overwhelmingly positive about what they learned, we left lesson plans and supplies for the teachers to use in their curriculum for upcoming years. Our project was very successful at introducing new topics of study to current educators and students because we ensured that science achievement standards were being met. (Session 25: Education Symposium; Tues. 2:50-3:10pm; Forum)
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81 PREDATION, SCRAMBLE COMPETITION, AND THE VIGILANCE GROUP SIZE EFFECT
*Steven L. Lima1, Patrick A. Zollner1 & Peter A. Bednekoff2
1Dept. of Life Sciences, Indiana State University, Terre Haute, IN 47809; 2Biology Dept., Eastern Michigan University, Ypsilanti, MI 48197 (LSLIMA@scifac. indstate.edu)
Birds devote less time to vigilance and more time to feeding as group size increases. This vigilance group size effect is typically viewed as predator-driven, but many suggest that it may be driven by scramble competition for food. Our results suggest that one need not invoke scramble competition to explain the vigilance group size effect in dark-eyed juncos (Junco hyemalis). We focused in particular on vigilance scanning concomitant with the handling of food items, since a decrease in food handling times (or scan durations) with increasing group size could be driven by scramble competition for limited food. However, food-handling scan durations decreased with group size in an environment with an unlimited supply of food. Furthermore, standard vigilance scans (scanning exclusive of food ingestion) also decreased with group size, and the durations of both types of scans increased under greater predation risk as expected under the predation paradigm. The group size effects in both food-handling and standard scan durations may reflect a lesser need for personal information about risk as group size increases. (Session 15: Predator/Prey I; Mon. 2:50-3:10pm; Gallery)
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155 THE EFFECTS OF KINSHIP ON EGG-DUMPING BEHAVIOR IN THE LACE BUG GARGAPHIA SOLANI
*Michael L. G. Loeb1, Lynn M. Diener2 & David W. Pfennig1
1Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280; 2Bard College, Annandale-on-Hudson, New York 12504 (mlgl@email. unc.edu)
In species where females show egg-dumping behavior, a single adult or adult pair cares for own offspring along with the offspring of egg dumpers. Fitness consequences of such alloparental care can be modified by kinship among egg dumpers and alloparents. However, it is not clear for any species if kinship among interactants affects oviposition choices of egg dumpers. In the lace bug Gargaphia solani (Heteroptera: Tingidae) some females behave as egg dumpers, and others behave as egg guards, protecting eggs and nymphs until they reach adulthood. We asked if G. solani egg dumpers discriminate between eggs of kin and eggs of nonkin in two different treatments. In one treatment we gave egg dumpers the choice of ovipositing among eggs of an unfamiliar nonsister, and eggs of a familiar full-sister. In a second treatment we gave egg dumpers a choice of an unfamiliar nonsister s eggs and an unfamiliar full-sister s eggs. Overall, egg dumpers preferred sisters eggs regardless of familiarity with sisters, suggesting that kin discrimination by G. solani egg dumpers is mediated by genetic labels rather than environmentally-acquired cues. (Session 31: Social behavior II; Tues. 4:10-4:30pm; Rooke)
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47 THE EFFECT OF NOISE MASKERS ON THE DETECTION OF AVIAN VOCALIZATIONS
*Bernard Lohr, Timothy F. Wright & Robert J. Dooling
Dept. of Psychology, University of Maryland, College Park, MD 20742 (blohr@psyc.umd.edu)
Noise plays an important role in influencing the distance over which biologically relevant signals may be detected and recognized (the active space of the signal). While birds have been popular subjects for studies of auditory perception using standard stimuli such as pure tones and broadband noise, little is known about the effects of noise on the perception of vocalizations in birds. Using an operant conditioning procedure, we measured thresholds in zebra finches Taeniopygia guttata and budgerigars Melopsittacus undulatus to detect conspecific and heterospecific vocalizations in two types of noise maskers, broadband noise and noise shaped to simulate a traffic spectrum. Budgerigars had lower thresholds than zebra finches for all vocalizations. Narrow bandwidth calls were easiest to detect, followed by intermediate bandwidth calls, and finally broadband calls. Broadband noise was a more effective masker than traffic noise, in which most of the energy fell below 1000 Hz. In general, our results conform to a power spectrum model of auditory function. (Session 10: Communication III; Mon. 9:50-10:10am; Rooke)
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P65 VIGILANCE IN A DESERT BIGHORN SHEEP (OVIS CANADENSIS NELSONI) POPULATION: BEHAVIORAL PLASTICITY AND THE ABSENCE OF LARGE PREDATORS
Kathy M. Longshore
Department of Biological Sciences, University of Nevada, Las Vegas, NV 89154-4004 (Longshore@ccmail.nevada.edu)
Bighorn sheep (Ovis canadensis) are known to vary vigilance in response to differences in group size, visibility, distance from escape terrain, and presence of neonates. This variation in vigilance, the result of a complex combination of individual differences in both genetic code and environment, can be expressed as norms of reaction. Thus for a population of bighorn sheep inhabiting a particular mountain range, the adaptive norm of reaction for vigilance is described by the set of phenotypic means expressed by the population over a range of environments. In this study, the mean norm of reaction for vigilance was characterized for the desert bighorn sheep (Ovis canadensis nelsoni) population inhabiting the River Mountains, Nevada, a low-elevaation mountain range uninhabited by large predators. Analysis of covariance was used to test effects of group size and distance to escape terrain on vigilance response. Results of the ANCOVA showed no effect of distance to escape terrain or group size on vigilance response. In addition, vigilance levels of ewes with lambs were similar to those without lambs. These results suggest there may be a cost to vigilance in desert populations which, in populations without predators, results in a flat norm of reaction. (General Posters; Sun. eve; Terrace)
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33 A RE-EVALUATION OF THE LOGIC OF PILFERAGE EFFECTS ON ENERGY REGULATION
*Jeffrey R. Lucas1, Vladimir V. Pravosudov1 & Denise L. Zielinski2
1Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, 2Biology Department, Wabash College, Crawfordsville, IN 47933 (jlucas@bilbo.bio.purdue.edu)
An often-stated prediction is that caching rates should drop when pilferage rates increase, and that animals should compensate for the reduced reliance on cached food by increasing mass. We showed in a previous study that both of these predictions were falsified under aviary conditions: Carolina chickadees increased caching rates when pilferage rates increased and (weakly) decreased mass. With this background, we re-evaluated the theoretical basis of the prediction using a dynamic program designed to be a better predictor than previous models of small-passerine foraging conditions. Our preliminary results indicate that caching rates can indeed increase when pilferage rates increase, although there is a threshold beyond which high pilferage rates cause a reduction (or cessation) of caching behavior. In addition, mass levels should increase with an increase in pilferage rates. Finally, the result of high pilferage rates is a reduction in both cache size and cache retrieval rates. The results suggest that we should re-evaluate our understanding of the role of pilferage on energy-regulation patterns. (Session 7: Foraging II; Sun. 4:30pm; Olin)
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62 FEMALE MATING PREFERENCES IN THE TWOLINE PUPFISH.
*Anna M. Ludlow & Murray Itzkowitz
Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015 (aml9@lehigh.edu)
Based on field observations, we tested the importance of male size, resource quality and female copying on the female mate preferences of the twoline pupfish (Cyprinodon bifasciatus). In aquaria, females were placed in an arena and were able to simultaneously observe and approach males on the two ends of a tank. When size differences were controlled for, females preferred to approach males on rocks as opposed to males on sand. When resource quality was controlled for, females preferred to approach a large male versus a small one. When male quality and resource quality were contrasted, females did not show a consistent preference for either trait. Finally, females preferred to approach a male that was observed consorting with another female. In this species, female mate choice appears to be a complex process involving the use of multiple traits. Field observations suggest that females may not always be able to mate with males on high-quality resources, and thus may need other characteristics to discriminate between males on less-preferred resources. (Session 12: Sexual selection II; Mon. 10:10-10:30am; Olin)
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P66 SOCIAL STIMULATION AND BREEDING BEHAVIOR IN ZEBRA FINCHES
*Joseph W. Luke1 & Wendy L. Hill2
1Department of Biology, Lafayette College, Easton PA 18042; 2Department of Psychology, Lafayette College, Easton PA 18042 (lukej@lafayette.edu)
Darling (1938) proposed that the reproductive system of colonial birds is influenced by being around other birds in breeding condition. In particular, he suggested that the enhanced social stimulation which occurs from witnessing the reproductive behaviors of neighboring pairs would accelerate the breeding cycles of others, via neuroendocrine pathways, and cause earlier and more synchronous laying. The purpose of this experiment was to determine whether social stimulation resulting from neighboring individuals would accelerate the breeding behavior of colonial Zebra Finches (Taeniopygia guttata). Newly-paired finches were exposed to one of two different social conditions: either an experimental pair was isolated from other finches (Socially Isolated Condition) or it was surrounded by four pairs of neighbors (Neighbor Condition). For three weeks, pairs were observed daily using continuous sampling techniques and their reproductive outputs were monitored (e. g. nest building, egg-laying). Pairs in the Neighbor Condition had significantly higher rates of courtship behaviors and aggression than those in the Socially Isolated Condition. Pairs in the Socially-Isolated Condition started to build nests sooner but took longer to complete them than did pairs in the Neighbor Condition. The importance of these findings and the limitations of the Darling Effect will be presented. (General Posters; Sun. eve; Terrace)
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55 ASYMMETRIC CONTESTS FOR SPAWNING SITES BETWEEN MONOGAMOUS CICHLID PAIRS.
Pamela A. E. Lynch & *Matthew J. Draud
Department of Biology, C. W. Post, Long Island University, Brookville, NY 11548 (mdraud@liu.edu)
Cichlid fish of the genus Archocentrus exhibit a biparental resource defense monogamous social system. In the field, males and females first form pairs and subsequently compete together for territories. We examined staged contests for artificial spawning sites between two previously formed pairs. The competing pairs were asymmetric in one or two of three characteristics: body size, residence, and pair bond duration. Experiments were designed to test the absolute and relative importance of these three asymmetries. Experiments involving only one asymmetry revealed that larger pairs defeated smaller pairs, prior residents defeated intruding pairs, and experienced pairs defeated novice pairs. Experiments involving two simultaneous asymmetries showed that body size was the single most important asymmetry, and that pair bond duration was as important as residence in determining the outcome of contests. Analyses of the escalated fighting behaviors performed by the pairs in these experiments suggest that these contests most closely followed the sequential assessment model. (Session 11: Resource Acquisition; Mon. 10:10-10:30am; Gallery)
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8 VARIABLE REPRODUCTIVE STRATEGIES IN COMMUNAL SPECIES: THE COOPERATION-INFANTICIDE MODEL
*Regina Helena Macedo1 & James S. Quinn2
1Departamento de Ecologia/IB, Universidade de Brasília, 70919-970; 2Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1 (rhmacedo@unb.br)
Several factors influence an individual's decision when faced with the dilemma of whether its self-interests are better served by cooperating or engaging in destructive behavior, such as infanticide. We present a model incorporating kinship among adult group members and progeny and social status to predict behavioral options for individuals of diverse backgrounds. The model organism used was the guira cuckoo (Guira guira), a bird that breeds communally and which exhibits behaviors ranging from full cooperation to infanticide. We suggest that communal breeders utilize the best available predictors for enhancing seasonal reproductive success, which change over time, and include the individual's assessment of: (i) probability of successful fertilization; (ii) number of eggs laid and incubated; (iii) position in group's hierarchy; (iv) relatedness to other adults; (v) relatedness to progeny; and (vi) possibility of renesting within breeding season. The model produces predictions that may be falsified through field observations and molecular analyses for this species, and which may be applicable to other species with similar social dynamics. (Session 2: Sexual Selection I; Sun. 2:30pm; Rooke)
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179 SIZE, MATING, EGG LOAD, SPEED AND HOME RANGE IN THE GOLDEN EGG BUG
*Rogelio Macías-Ordóñez
Instituto de Ecología, A. C., Apartado Postal 63, Xalapa, Veracruz 91000, Mexico (rogelio@ecologia.edu.mx)
A population of the golden egg bug, Phyllomorpha laciniata (Heteroptera: Coreidae), was studied in Northeastern Spain. Females are known to lay eggs on the back of conspecifics of both sexes in this and other populations around the Mediterranean. The study aimed to find relations between dorsal area, mating behavior, egg load, speed and home range in both sexes. Direct observations were carried out in the field in the Spring of 1998. Censuses were made daily on a 25 x 25 m plot in which individuals were uniquely tagged, sexed, measured, and their egg load and behavior recorded. Races between loaded and unloaded individuals of both sexes were staged, and female oviposition on other females was assessed in single-sex enclosures. Size assortative mating was found. Female but not male size was positively correlated with egg load. When given the opportunity, females laid eggs on other females as much as on males. Egg load had no effect on speed. Previous suggestion of intraespecific parasitism are partially supported. (Session 36: Sexual selection VI; Weds. 10:10-10:30am; Olin)
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P67 HORMONALLY MEDIATED CUES FOR RECOGNIZING MATES BY BURYING BEETLES
*Katharine A. Madjid & Michelle Pellissier Scott
Biology Program and Department of Zoology, University of New Hampshire, Durham, NH 03824 (kamadjid@hopper.unh.edu)
A male and female burying beetle (Nicrophorus orbicollis) cooperate to bury and prepare a carcass and to rear a brood. They defend the resource and nest from intruders - initially from consexuals, and later from all strangers. Thus each must recognize its mate to cooperate with it yet protect its nest from strangers. We investigated the cues beetles use to distinguish their mate from strangers. Males removed from the brood chamber to a neutral arena five days after being given carcasses rejected non-breeding female strangers but accepted their mates. They also accepted female strangers if she too had been with a carcass five days. These data suggest that male N. orbicollis do not recognize individual characteristics but use cues generated by breeding. To examine this further we treated virgin females with methoprene to mimic the high juvenile hormone level present in N. orbicollis at this stage. We found that males accepted the methoprene-treated females as they did their mates and the female strangers at the same breeding stage. (General Posters; Sun. eve; Terrace)
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17 THE ROLE OF EARLY EXPERIENCE ON SUBSEQUENT REPRODUCTIVE SUCCESS IN OLDFIELD MICE
*Susan W. Margulis1 & Mark W. Nabong2
1Department of Conservation Biology, Brookfield Zoo, Brookfield, IL 60513; 2University of Chicago, Chicago, IL 60637 (s-margulis@nwu.edu)
Studies of a variety of taxa have almost universally shown an increase in survivorship between the first cohort of young raised by a female (or both parents) and subsequent litters. We examine the role of experience with pups during the subadult period on maternal behavior and reproductive success in the monogamous oldfield mouse (Permyscus polionotus). Experienced females remained with their parents through the rearing of a subsequent sibling litter. Inexperienced females were removed from their parents at 20 days of age, and had no prior exposure to pups before they themselves reproduced. Twenty-four experienced females and 24 inexperienced females (each a full-sibling of an experienced female) were paired with non-inbred, inexperienced males. Litter survival improved significantly with experience and increasing parity, with experience showing a stronger effect than parity. Pairs with experienced females demonstrated enhanced maternal behavior and averaged significantly more surviving pups than did inexperienced pairs. These findings support the contention that individuals may accrue significant fitness benefits by delaying their own reproduction and gaining experience. (Session 4: Parental Care I; Sun. 2:10pm; Gallery)
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4 BALANCING VISUAL AND CHEMICAL COMMUNICATION: AN INTERSPECIFIC STUDY
Emília P. Martins1, Antonieta Labra2, Monique P. Halloy3 & *Julie P. Tolman1
1Department of Biology, University of Oregon, Eugene, OR 97403; 2Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile; 3 Instituto de Herpetolog Fundaci Miguel Lillo, Miguel Lillo 251, Tucuman Argentina 4000 (jmtolman@darkwing.uoregon.edu)
Most lizards use both visual and chemical cues to communicate with each other. Liolaemus (Tropiduridae), for example, use head-bob displays and chemical secretions to defend territories and interact with mates. If these types of cues can communicate similar information, we would expect to see a trade-off or negative correlation between the use of visual and chemical signals, and possibly also between the complexity of structure of the two types of signals. In this study, we use data from several species of Liolaemus lizards in a phylogenetic comparative analysis to test this prediction. We found a negative correlation between aspects of the head-bob display and the structures used to produce chemical secretions (mainly precloacal pores). The role of potential trade-offs in determining this relationship is discussed. (Session 1: Communication I; Sun. 2:50pm; Forum)
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74 APPEASEMENT SIGNALS IN A LIZARD?: HEADBOB DISPLAYS IN THE TCI ROCK IGUANA
*Emília P. Martins & Kathryn E. Lacy
Department of Biology, University of Oregon, Eugene, OR 97403 (emartins@work.uoregon.edu)
Lizard headbob displays are used in a variety of contexts, and have been described as serving aggressive, courtship, and broadcast functions. Early studies (Iverson 1978) suggested that the Turks & Caicos Island rock iguana (Cyclura carinata) is unusual in that headbob displays are also produced in an appeasement context. In this study, we conducted focal animal samples of Cyclura carinata in the field, videotaping displays during breeding and non-breeding seasons. We use these data to consider both the detailed structure of the headbob displays and the social and behavioral contexts in which they are produced. Results suggest that the displays are used frequently by females and juveniles as they approach larger animals, particularly during the non-breeding season. They may thus serve an appeasement function. (Session 14: Communication IV; Mon. 2:10-2:30pm; Rooke)
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195 DEVELOPMENT OF RECOGNITION CUES IN GROUND SQUIRRELS
Jill M. Mateo
Department of Psychology, Cornell University, Ithaca NY 14853 (jmm52@cornell.edu)
Despite extensive research on kin recognition and the development of nepotism, little is known about ontogenetic changes in the cues used for recognition. In juvenile and adult Belding's ground squirrels Spermophilus beldingi, secretions from oral and dorsal glands are individually distinct and kin distinct, and appear to function in social recognition. Behavioral studies of recognition suggest that these cues may change across development, particularly around the time of weaning and emergence from natal burrows (around 25 days of age). I conducted a series of studies to determine when young begin producing oral-gland odors and when these odors become individually distinct. Using an habituation-discrimination task with captive S. beldingi, I found that 21-d old pups, but not 7- or 14-d old pups, produce detectable odors. Odors are not individually distinct until 28-d of age, after young have emerged from their burrows and begun foraging. More importantly, an individual's odor changes dramatically after emergence: odors produced at 20 and 40 days of age are perceived as dissimilar. Changes in odors around weaning may be a proximate explanation for why S. beldingi littermate preferences are not consolidated until after natal emergence, and indicate that conspecifics must update their recognition templates as young develop. (Session 39: Communication VII; Weds. 2:30-2:50pm; Rooke)
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173 MATING GAMES SQUID PLAY
J. A. Mather
Department of Psychology & Neuroscience, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4 (mather@uleth.ca)
Mating systems in Cephalopods are poorly understood and most species are solitary or live in huge groups. Observation by snorkelling of the small-group-living Sepioteuthis sepiodea in coastal water at Bonaire allowed a description of mating strategies in this species. Constraints on this system were membership in the small yet open group, good visual capacity and ability at skin pattern production, maturation within the system and a semelparous reproductive strategy. Visual skin signals indicating sex, status and motivation were exchanged. Male squid were continually competitive and females were selective of males. Males sought to guard females and pairs formed in the group, yet both sexes sought extra-pair reproductive opportunities, with different techniques over time. Male squid attempted to mate repeatedly and females responded with a range of mating avoidance strategies. At the end of the lifespan, pairs were isolated from the group and females sought egg-laying opportunities under the consortship of males. This system offers another look at mate selection and mate choice and can be compared with those in small-group mammals and re-mating birds. (Session 34: Mechanisms III; Weds. 11:10-11:30am; Gallery)
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144 DEVELOPING LIFE SCIENCE CURRICULAR MATERIALS USING A PARASITIC WASP
Robert W. Matthews
Department of Entomology, University of Georgia, Athens, GA 30602 (rmatthew@arches.uga.edu)
I will describe a four-year project funded by the National Science Foundation in which a common parasitoid wasp, Melittobia digitata (Hymenoptera: Eulophidae), was transformed into the WOWBug, a new instructional organism. Used previously to train a few graduate students, WOWbugs are now used to teach a variety of life science concepts and process skills to thousands of middle school and high school biology students. Highlights of the process from idea to implementation will be presented. Examples of innovative curricular materials relating to animal behavior concepts will be shared. Practical issues arising during development, commercialization, and dissemination of project products will be discussed. Suggestions and recommendations for others potentially interested in venturing into these relatively uncharted waters will be offered. Further information about the WOWBugs project may be found on the web, http://entomology.ent.uga.edu/wowbugs/. (Session 29: Education Symposium; Tues. 3:30-3:50pm; Forum)
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82 SEX WITH STRANGERS, SIBLINGS, OR SELF?: MATE-CHOICE DECISIONS OF A HERMAPHRODITE SNAIL
Thomas M. McCarthy
Center for Ecology, Evolution & Behavior, 101 Morgan Building, University of Kentucky, Lexington, KY 40506 (tom@ceeb.uky.edu)
A major issue in behavioral ecology is the study of mate choice. Most animals do not mate indiscriminately, but prefer some potential mates to others. One factor that should influence mate choice is genetic similarity. Theory suggests organisms should avoid mates that are genetically too similar (inbreeding avoidance) or too dissimilar (outbreeding avoidance). Species capable of both cross-fertilization and self-fertilization can serve as model systems for investigating factors that influence mate-choice decisions. Hermaphroditic snails offer a unique opportunity to examine this issue since every mature individual is a potential mate, and possibilities for mate choice range from self-fertilization to crosses between members of different populations. In preliminary experiments, snails (Physa) favored individuals originating from populations other than their own as mates. The current study asks if mate-choice decisions might be influenced by the degree of relatedness of potential mates. In addition to behavioral observations, reproductive output is being examined to explore possible fitness consequences resulting from mate-choice decisions, including inbreeding and/or outbreeding effects. (Session 16: Sexual selection III; Mon. 1:30-1:50pm; Olin)
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145 HOW TO MISCOMMUNICATE WITH YOUR PET
Patricia B. McConnell
Department of Zoology, University of Wisconsin, Madison, WI 53706 (pbmcconn@facstaff.wisc.edu)
Subtitled: Conversations between two species without a translator. Although love can move mountains, it can't always stop your dog from biting the neighbor's daughter or your cat from urinating on your pillow. This presentation will incorporate live and video demonstrations of how Homo sapiens and Canis lupus domesticus often (and unintentionally) mis-communicate. For example, the affiliative ventral-ventral contact of most primates, including humans, is probably interpreted by dogs as a threat or dominance display. Regretably this difference in species predispositions probably results in thousands of bites every year. The presentation will include work with dogs on stage to illustrate how the relationship between people and their pets can excite and stimulate an interest in the study of animal behavior. (Session 29: Education Symposium; Tues. 4:10-4:30pm; Forum)
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177 CAROTENOID-BASED ORNAMENTATION IS NOT A SIGNAL OF SOCIAL STATUS IN MALE HOUSE FINCHES
Kevin J. McGraw
Department of Zoology and Wildlife Science, Auburn University, Auburn, AL 36849 (mcgrakj@mail.auburn.edu)
The status signaling hypothesis (SSH) was devised to explain the functional significance of avian ornamental coloration in the non-breeding season. However, to date this hypothesis has been well-tested only with melanin-based coloration. There is evidence that the cost of production, and thus information content, of carotenoid- and melanin-based ornaments are fundamentally different, but only one experimental test of the SSH has focused on a carotenoid ornament. We tested the SSH in male house finches (Carpodacus mexicanus) by artificially manipulating plumage color of first-year males and by pairing unfamiliar males in a series of dominance trials in captivity. Artificial male color was not significantly associated with win/loss outcome, but body mass was an accurate predictor of dominance. We also found that the correlation between winter dominance and the natural plumage brightness of male house finches approached statistical significance. Comparable results now from two passerine species exhibiting carotenoid-based ornamentation suggest that these ornaments do not act as reliable visual cues for the assessment of social status by males in the non-breeding season, but instead are merely correlated with winter dominance. However, the trend for naturally drab male house finches to dominate naturally bright birds does not fit the predictions of honest signaling theory, and as a result this apparent paradox calls for further investigation. (Session 35: Communication VI; Weds. 11:10-11:30am; Rooke)
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197 TEAT PREFERENCES IN VOLES
B. A. McGuire
Department of Biological Sciences, Smith College, Northampton, MA 01063 (bmcguire@science.smith.edu)
In some mammals, young exhibit preferences for anterior or posterior teats. Such preferences could reflect differences among teats in yield or composition of milk, ease of colostrum extraction, accessibility, or likelihood of receiving maternal care or being dislodged while suckling. In a previous study I marked young prairie voles and scored the locations of teats suckled every other day from day 4 to day 16 postpartum. Prairie vole pups preferred hind teats over middle teats and least preferred front teats. I have conducted an identical study with pine voles, a species with only two pairs of teats (hind and middle). Young pine voles preferred hind teats over middle teats. Next I observed litters of the two species daily from day 3 to day 10 postpartum in a seminatural environment and scored the frequencies with which pups at different teats were groomed by their mother or dislodged by her movements. Preliminary observations suggest that pups at hind teats in both species are not groomed more frequently but are dislodged less frequently than pups at more anterior teats. (Session 40: Parental Care III; Weds. 1:30-1:50pm; Olin)
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172 CORRELATION OF BEHAVIOUR AND REPRODUCTIVE HORMONES IN THE INDIAN RHINOCEROS, RHINOCEROS UNICORNIS
*Merryn D. McIninch1, Karen L. Goodrowe2 & Suzanne E. MacDonald1
1York University, Toronto, ON M3J 1P3; 2 Toronto Zoo, Scarborough, ON M1B 5K7 (mmcininch@hotmail.com)
The endangered Indian rhinoceros Rhinoceros unicornis is solitary in nature and difficult to breed in captivity. Placing animals together when the female is not sexually receptive can result in serious aggression. The objective of this study was to identify correlations between hormonal patterns of the estrous cycle and male and female behaviours, with the goal of creating a behavioural chart for predicting the optimal time for breeding introductions. Urine samples were collected from two female rhinos for 133 and 342 days and analysed for estrone conjugates (EC) and pregnanediol-glucuronide by enzyme-immunoassay. Behaviours of the females and the males housed with them were recorded on the same days as urine collection. Mean cycle length, based on intervals between EC peaks, was 49 6 days (n=7 cycles). Based on ANOVA, behaviours related to EC elevations were: vocalisation (P < 0.010), male locomotion (P < 0.050), female urine squirting (P < 0.010) and female flehmen (P < 0.050). These results demonstrate that behavioural observations can assist in timing breeding introductions. (Session 34: Mechanisms III; Weds. 10:50-11:10am; Gallery)
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216 SWIMMING BEHAVIOR OF MALES AND HERMAPHRODITES IN AN ANDRODIOECIOUS CLAM SHRIMP EULIMNADIA TEXANA (CRUSTACEA: CONCHOSTRACA)
*Vicki L. Medland1, Naida L. Zucker1 and Stephen C. Weeks2
1Department of Biology, Box 30001 - MSC 3AF, New Mexico State University, Las Cruces, NM 88003; 2Department of Biology, University of Akron, Akron, OH, 44325 (vmedland@nmsu.edu)
In order to model the potential frequency of outcrossing by hermaphrodites, we investigated whether encounter rates between males and hermaphrodites are random or directed. A single male or hermaphrodite shrimp was introduced into the center of a narrow chamber that had its ends partitioned by Plexiglas or mesh barriers. One end contained animals of the opposite sex, or water that had previously contained these animals. The other end contained shrimp of the same sex, water that had held these animals, fairy shrimp, or plain water. Males did not alter mean swimming speed or spend more time near partitioned hermaphrodites or water that had contained them. Hermaphrodites decreased mean swimming speed in the presence of males and also spent more time near partitioned males or water that contained males, suggesting hermaphrodites respond to a chemical released by males. Modified swimming behavior probably facilitates inter-sexual contact, increasing opportunities for outcrossing. (Session 44: Reproduction and mating; Weds. 3:30-3:50pm; Olin)
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P68 EVIDENCE OF MATE TRAILING IN THE GIANT HAIRY DESERT SCORPION
J. M. Melville, *S. K. Tallarovic, L. K. Gundersen & P. H. Brownell
Department of Zoology, Oregon State University, Corvallis, OR 97333 (melvillj@bcc.orst.edu)
Scorpions appear to detect the presence of mates using substrate borne chemical cues. The primary role of these sex pheromones in reproduction has not has not been thoroughly investigated. Desert scorpions are solitary nocturnal sit and wait predators. During the breeding season scorpions are found 'wandering' the dune environment presumably in search of mates. Combined with the observation that female scorpions produce specular trails, the selective pressure associated with mate finding indicates that mate trailing in scorpions would be highly adaptive. Using the giant hairy desert scorpion (Hadrurus arizonensis) as a model, we have found that sand labeled by reproductive female scorpions is capable of releasing several behaviors associated with mating. These behaviors include 'juddering', 'tail-wagging' and 'lunging'. We also have evidence that male giant hairy desert scorpions are capable of following the trail of female conspecifics using observational studies in open arenas and experiments using a classic Y-maze design. Although specific sex pheromones have not been isolated in any scorpion, this strongly suggests that chemical cues are used in mate finding. (General Posters; Sun. eve; Terrace)
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P69 EFFECTS OF TEMPERATURE AND TESTOSTERONE ON MATING IN MALE BIG BROWN BATS
Mary T. Mendonca & *Maggie C. Smith
Department of Zoology, Auburn University, Auburn, AL 36849 (smitmag@mail.auburn.edu)
Anectodal observations of vespertilionid bats indicate that mating occurs during fall and winter months, when testosterone is basal in males. A previous study on big brown bats, Eptesicus fuscus, found that males were more likely to mate if exposed to a period of low temperature (4°C) with subsequent arousal than if maintained at higher temperature (25°C). It also found that males would mate regardless of testosterone level. We further tested this observation by exposing intact, castrate, castrate+testosterone, castrate+flutamide male Eptesicus to different temperature regimens (20, 10, and 5°C) for different time periods (1, 4, and 7 days) from Nov 1998-Mar 1999. Bats were observed for 4 days after arousal. Bats did not mate after exposure to 7 days of 10°C in late November. However, 7 days of 5°C in December, stimulated mating in 40% of males from all treatment groups except flutamide (an anti-androgen). Percent of males mating varied from 40-80% but did not differ significantly among temperature regimens (Dec-Mar) nor steroid treatment groups, except for flutamide-treated males. This group exhibited significantly lower mating frequencies (General Posters; Sun. eve; Terrace)
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66 DOES VARIATION IN THE QUALITY/QUANTITY OF MALE PHEROMONES AND ULTRAVIOLET REFLECTANCE AFFECT FEMALE CHOICE IN A BUTTERFLY?
*Randi S. Mendoza & Ronald L. Rutowski
Department of Biology, Arizona State University, Tempe AZ 85287-1501 (r.mendoza@asu.edu)
In the orange sulfur, Colias eurytheme, the presence of pheromones and UV reflectance are critical signals in intraspecific communication. Males produce at least 5 different pheromones on the dorsal surface of their hindwings; therefore variation between individuals exists both the amount and ratio of each pheromone component. These pheromone component qualities (PCQs), along with UV reflectance, may be the basis for female choice in this species. To study whether females make mating choices based on the PCQs and UV reflectance signals given off by males, I presented virgin females (n=45) to a minimum of five males in the field. During the trials I recorded courtship and mating behaviors of males and females. All males were captured for analysis of PCQs and UV reflectance. Results will be discussed with respect not only to the courtship signaling, but also to male persistence in courtship, male age and size. These results will shed light on how females act as a selective force on a complex suite of male characteristics. (Session 12: Sexual selection II; Mon. 11:30-11:50am; Olin)
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P70 WHY ORCAS SOUND LIKE HUMPBACK WHALES
*E. Mercado II1, S. O. Murray2 & L. N. Frazer3
1CMBN, Rutgers-Newark, 197 University Ave., Newark, NJ 07102; 2ITD, UC-Davis, 2201 Academic Surge, 1 Shields Ave., CA 95616; 3SOEST, University of Hawaii at Manoa, HI 96822 (mercado@pavlov.rutgers.edu)
Orcas produce a wide variety of sounds that have been described traditionally as clicks, pulsed sounds, and whistles. These three sound types correspond to modes along a continuum of quasiperiodic signals with decreasing periods (e. g., click trains have the longest duration periods and whistles have the shortest). Unlike many other delphinids, orcas use the middle of this continuum (pulsed sounds) more extensively than the extrema (clicks and whistles). Orcas commonly produce sounds with pulse rates between 120-4000 Hz. These sounds typically consist of several harmonically related spectral bands between 1-2 s in duration. The distribution of energy across these bands is non-uniform with upper harmonics sometimes containing more energy than lower harmonics. Interestingly, all of the aforementioned features of the orca's sound repertoire are also evident in the repertoire of humpback whales. These similarities cannot be attributed to physiological mechanisms related to size because other cetaceans of comparable size (e. g., minke or sperm whales) have very different repertoires. Although such similarities may be coincidental, it is also possible that they reflect adaptations to ecological constraints on sound usage faced by both species. We used computational and comparative techniques to investigate this possibility. The results of these analyses suggest that the pulsed sounds of both orcas and humpback whales are well suited for long range sonar in a shallow water environment. (General Posters; Sun. eve; Terrace)
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Keynote Lecture Sun. 8:30am
Coleman Hall

Keynote: INTO THE UNDERWORLD WITH RICHARDSONS GROUND SQUIRRELS: BEHAVIOURAL ECOLOGY OF A GROUND-DWELLING HIBERNATOR
Gail R. Michener
Biological Sciences, University of Lethbridge, AB, Canada T1K 3M4 (michener@uleth.ca)
Behavioural studies of North American ground squirrels tend to concentrate on their activity when above ground during the active season even though these animals spend the majority of their lives underground. Indeed, many critical events such as mating, parturition, infancy, sleeping, and hibernating occur primarily or exclusively underground. Recent goals of my long-term study of Richardson's ground squirrels include exploring aspects of the underground lives of animals to provide a counterpoint to their above-ground existence. Sexual differences in behaviour so evident in the active season of Richardson's ground squirrels extend to the hibernation season; for example, only males store food in the hibernaculum and males spend less time than females in torpor, behaviours that enable males to prepare for the exigencies of the post-hibernation mating season. For both sexes, the hibernaculum is a chamber dedicated solely to hibernation and is isolated from the rest of the burrow system. In contrast, the nest in which a female bears and rears infants is multi-purpose and accessed by multiple entrances. Whereas females are intolerant of sharing underground space during late pregnancy and lactation, close female kin share sleeping chambers in early pregnancy and sometimes again post-lactation, indicating that kinship bonds persist throughout their lives.
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57 SCENT MARKING DISCRIMINATES TERRITORY BOUNDARIES AND SOCIAL STATUS IN WILD GOLDEN LION TAMARINS
*K. E. Miller & J. M. Dietz
Department of Biology, University of Maryland, College Park, MD 20742 (balesKaren@aol.com)
Scent marking may function to delimit territories, mark resources, and communicate dominance or reproductive status. Golden lion tamarins (Leontopithecus rosalia, GLTs) are territorial and cooperative breeders. I explored the extent to which scent marking maintains territories and communicates readiness to breed and dominance status. I recorded all occurrences of scent markings (n=791) for 9 groups of GLTs during SeptemberNovember 1997 and JuneOctober 1998 (n=59 days). Preliminary data suggest that scent marking functions to maintain territories. Scent marking was more frequent on days of intergroup encounters than other days (paired t- test, df=24, p=. 004). Scent marking does not communicate readiness to breed, but may communicate dominance status within groups. Reproductive pairs scent marked at higher frequencies than other group members (Wilcoxon signed rank test, p<. 0001, n=59 pairs). However, there was no difference in scent marking frequency between members of reproductive pairs, regardless of which animal was dominant in the pair. The reproductive pair may use scent marking to maintain dominance over adult helpers within the cooperatively breeding group. (Session 11: Resource Acquisition; Mon. 10:50-11:10am; Gallery)
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207 ACQUISITION OF CHEMOSENSORY PREDATOR RECOGNITION BY BROOK TROUT
*R. S. Mirza & Douglas P. Chivers
Department of Biological Sciences, University of Maine, Orono, Maine 04469 (RMIRZA81@maine.edu)
A diversity of fishes release chemical alarm pheromones upon being attacked or captured by a predator. These alarm pheromones warn other conspecifics of danger and may serve as proximate cues to mediate learned recognition of unknown predators. In a laboratory experiment, we tested the response of hatchery-reared brook trout (Salvelinus fontinalis) to one of four treatments: 1) brook trout skin extract, 2) swordtail skin extract, 3) water conditioned by a single brook trout disturbed by a predatory bird model and 4) water conditioned by a single undisturbed brook trout. Trout exposed to conspecific skin extract, but to no other stimuli, exhibited a significant reduction in movement, a significant increase in shelter use and altered their foraging behavior. In a follow-up experiment, we exposed predator-na brook trout to the odor of chain pickerel (Esox niger) that was paired with brook trout skin extract, water conditioned by a disturbed brook trout or distilled water. After 24 hrs, we retested trout for a response to pickerel odor alone to determine if the trout were able to learn to recognize the pickerel based on their previous experience. Our results indicate that hatchery managers may be able to train hatchery-reared fishes to recognize potential predators prior to being stocked. (Session 42: Predator/prey IV; Weds. 3:30-3:50pm; Gallery)
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P12 NIPPLE WARS: DO GRASSHOPPER MOUSE PUPS SHOW TEAT PREFERENCES?
James D. Moodie
Department of Biological Sciences, Idaho State University, Pocatello, ID 83209 (moodjame@isu.edu)
Sibling competition is a proposed explanation for tenacious nipple attachment exhibited by some rodent species. One predicted outcome of this hypothesis is that rodent pups should display teat or teat-pair fidelity to defend preferred nipples. Grasshopper mice (Onychomys spp.) are known to be a tenacious nipple-attachment species, and they meet the expected life history parameters that promote sibling competition: low number of teats (six) and higher than average number of young (four). I tested whether grasshopper mouse pups show teat preferences and teat/teat-pair fidelity. To conduct the study, I observed twenty-four litters from different mothers, with litter sizes ranging from three to five pups. I noted individual pup location prior to a milk let-down event. Across let-down events, pups suckled from all nipples indiscriminately, thus showing no teat preference. Additionally, no teat/teat-pair fidelity was detected. I propose that how milk is delivered to offspring will determine pup strategies for competing with siblings. (Founders Award poster; Sun. eve; Terrace)
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63 DEFINING THE SEXUAL SIGNAL VERTICAL BARS IN RELATION TO FEMALE PREFERENCE IN XIPHOPHORUS CORTEZI
*Molly R. Morris & Jason A. Elias
1Department of Biological Sciences, Ohio University, Athens, OH 45701
Vertical bars function as a sexual signal that attracts females and deters rival males in swordtail fishes. This male trait, however, consists of several components that could potentially influence female preference. Therefore, as part of a long-term comparative study examining the evolution of the bars in relation to preference for the bars, we set out to define the important components of this trait in relation to female preference. Xiphophorus cortezi females preferred more bars in a study that reduced bar number by removing the posterior-most bars, therefore reducing bar span as well. We tested the hypothesis that females prefer greater bar span (not bar number per se) by giving females a choice between males with large bar spans and small bar spans while holding bar number constant. Females showed a significant preference for the smaller bar span, which we interpret as a preference for greater bar frequency (bars/mm). We discuss these results in relation to the visual acuity of X. cortezi females and their preference for patches over bars. (Session 12: Sexual selection II; Mon. 10:30-10:50am; Olin)
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19 EFFECTS OF INFANTS AND NON-MOTHERS ON MATERNAL BEHAVIOR IN A WILD TROOP OF SQUIRREL MONKEYS (SAIMIRI SCIUREUS)
Larkspur S. Morton
Animal Behavior Graduate Group, University of California, Davis CA 95616 (lsmorton@colby.edu)
Based on extensive studies of other small bodied primates we might expect squirrel monkey mothers to benefit from allomaternal assistance in caring for their large, fast-growing infants. Laboratory studies of infant caretaking in Saimiri suggest the same, however, field studies are generally lacking. A ten-month field study was conducted in Manu National Park in Peru on an habituated squirrel monkey troop. Subjects of the study were the adult and juvenile females and the current year s infants (up to 12 weeks of age). Subjects were individually identified. Analysis of individual scan and focal data revealed that mothers traveled more and insect foraged less when carrying infants and also that when insect-foraging they did so at higher rates when unencumbered. Allomaternal care was observed, starting in the 3rd week of infant life. There was a significant negative correlation between infant carrying by mothers and allomaternal involvement with their infants; mothers with helpers carried less in some weeks. This study provides the first evidence from the field showing clear effects of infants on squirrel monkey mothers and also suggesting that allomothers may play an important role in reducing costs of care for mothers in this small bodied New World primate. (Session 4: Parental Care I; Sun. 2:50pm; Gallery)
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P13 A BEHAVIORAL COMPARISON OF GIRAFFE IN WILD AND CAPTIVE ENVIRONMENTS
Anna A. Mosser
The University of Chicago, 1913 E. River Parkway, Minneapolis, MN 55414 (aamosser@midway.uchicago.edu)
By examining behavioral differences which might exist for members of a species living in different environments, a greater understanding of the functions and importance of certain behaviors can be gained. Giraffe Giraffa camelopardalis at the Brookfield Zoo, Chicago, were compared to giraffe in the Serengeti National Park, Tanzania. The zoo contained inside and outside enclosures for the giraffe. The most notable behavioral difference was represented by a much greater proportion of time spent feeding in the wild. The outside zoo environment did lend to behavior more similar to that seen in the wild, especially in respect to the variety of behaviors displayed and the level of interaction between individuals. The lack of time spent feeding in captivity may be linked to the stereotyped licking behavior, seen frequently in the inside zoo enclosure. This study has stressed certain behaviors as important to giraffe, such as foraging for food, and suggested ways in which captive environments may be improved for this species. (Founders Award poster; Sun. eve; Terrace)
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P71 EFFECT OF TURBIDITY ON MATING PREFERENCES IN A SPLITFIN FISH
*A. Moyaho, C. Macias & E. Avila
Instituto de Ecología, Universidad Nacional Autónoma de México. Ap. Postal 70-275, C. P. 04510. México, D. F. (amoyaho@miranda.ecologia.unam.mx)
Males of the freshwater fish (X. variata) have speckle-like spots on their flanks. Marked population differences in the number of speckles have ensued in a close association with different water color habitats. This study examines 1) whether female choice contributes to population differences, and 2) whether turbidity of water constrains female preferences. Each experiment offered females a choice between two native or alien males differing in the number of speckles, and a control female. We used individuals from four populations, tested in both turbid and nonturbid conditions. Males from nonturbid populations had more speckles than turbid groups; F(3, 77)= 36. 8, p<0.001. There were no significant differences between turbid and nonturbid treatments, and females did not discriminate between native and alien males. Except for a nonturbid population, the other did not distinguish between choices. These results suggest that, at least under these experimental conditions, females do not seem to contribute to population variation in speckle number, and neither turbidity of water affects preferences. (General Posters; Sun. eve; Terrace)
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P72 SIDE-DOMINANCE OF CONSTRICTION IS ABSENT IN GRAY RAT SNAKES (ELAPHE OBSOLETA SPILOIDES)
Stephen J. Mullin
Department of Biology, University of Central Arkansas, Conway, AR 72035-0001 (smullin@mail.uca.edu)
Lateralization of the brain (handedness) has been documented in many species of mammals, but studies addressing bias in coiling direction in snakes (an indicator of lateralization) are few and inconclusive. I offered adult male Mus domesticus to adult gray rat snakes (Elaphe obsoleta spiloides) in enclosures that simulated natural habitat conditions. Encounters between individual prey and predator were recorded on videotape and subsequently analyzed to determine position of the prey relative to any physical structure, strike location on the prey and coiling direction of the snake. Subjects did not exhibit a preference for coiling direction, either within individuals fed on multiple occasions or across all individuals examined. Additionally, coiling direction was not influenced by the location of the prey when the predator's strike was initiated or the region of the prey's body first contacted during the strike. However, similar to other members of this genus, the dorsal side of the snakes' constrictive coils was oriented towards the strike location in nearly all occasions. (General Posters; Sun. eve; Terrace)
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192 GENETICS OF THE CANARY VOCAL COMMUNICATION SYSTEM
Paul C. Mundinger & Joseph Emmett
Department of Biology, Queens College/CUNY, Flushing, NY 11367 (paul_mundinger@qc.edu)
Recent crosses of two inbred canary strains (Roller and Border canaries) yielded parental types, reciprocal cross hybrids, and both backcrosses (N=47 males) individually reared in acoustic chambers and choice tutored. Their patterns of selective song learning outlined a genetic system that affects song learning/production. It is a polygenetic system; the genes are on multiple chromosomes; sex-linked factors have a major affect on Border song; autosomal factors affect song too, especially Roller song. Parallel studies of calls reveal that the juvenile hunger/location call and adult flight call patterns are affected by genetic background too. Some of the call development evidence suggests that genomic imprinting may be involved and/or that sex-linked factors are. In summary, the structure of at least two calls was indirectly affected by artificial selection on song. This suggests that genes that affect song development also affect call development. At least for the canary, it seems that songs and calls are components of a single vocal communication system that is heritable via an integrated genetic system. (Session 39: Communication VII; Weds. 1:30-1:50pm; Rooke)
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12 EFFECTS OF FOOD ABUNDANCE ON DEMOGRAPHY OF PAPER WASPS)
Hillary A. Nadeau
Binghamton University, Biological Sciences, Binghamton, NY 13902-6000 (BF20357@binghamton.edu)
Many predatory insects face periods of prey scarcity in the field, which can affect growth, development, reproduction and behavior of the predator. I studied such effects on the paper wasp Polistes fuscatus. For two summers individual nests were provided with high or low food levels. The two summers differed in length of season and temperature. Both food abundance and temperature appear to affect demography of the wasps. High fed nests produced significantly larger offspring and cells than low fed nests during the cool summer. In contrast, there was no significant difference in size of offspring and cells between high and low food levels during the warm summer. Nest size (total number of cells) of high and low fed nests was similar during the cool summer, but during the warm summer high fed nests were larger than low fed nests. During the cool summer, both high and low food levels produced similar numbers of wasps, but during the warm summer, high fed nests produced many more offspring. Such differences between the two summers could be due to the wasps responding to summer temperatures as an indicator of length and severity of winters. (Session 3: Foraging I; Sun. 2:10pm; Olin)
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50 TIMING OF SONG ONSET DURING VOCAL INTERACTIONS IN BIRDS: ASYMMETRIES AND THEIR IMPLICATIONS
Marc Naguib
Freie Universitaet Berlin, Institut für Verhaltensbiologie, Haderslebener Str. 9, D-12163 Berlin, Germany (mnaguib@zedat.fu-berlin.de)
The timing of songs during vocal interactions in male passerines is an important component in territorial signaling since it can provide information on the signaler's state or quality. Here, I present results from interactive and two-speaker playback experiments on male territorial common nightingales, Luscinia megarhynchos. I investigated consequences of a simulated singing strategy (song alternating or overlapping) for the singing counterpart as well as for other listening (eavesdropping) rivals. Nightingales provide an excellent system to study the dynamics and meaning of vocal interactions since they vocally interact with each other extensively during diurnal and nocturnal song. The results of these studies indicate that subjects timed their songs differently when overlapped by playback and that they seemed to retaliate against overlappers. In addition, the experiments show that territorial males attend to other's interactions and use information obtained from asymmetries during others' interactions in their response towards them. Obtaining information directly from a counterpart as well as indirectly by listening to others' interactions underlines the complexity of information gathering in vocal long range communication systems. (Session 10: Communication III; Mon. 10:50-11:10am; Rooke)
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118 EFFECTS OF ADAPTIVE BEHAVIOR IN MODELS OF ASYMETRICAL INTRAGUILD PREDATION
*John H. Niedzwiecki, Patrick W. Crumrine, Thomas M. McCarthy, Alena M. Walters, R. Craig Sargent, Andrew Sih & Philip H. Crowley
Center for Ecology, Evolution and Behavior, School of Biological Sciences, University of Kentucky, Lexington, KY 40506-0225 (john@ceeb.uky.edu)
Interactions among predators, though poorly documented to date, are clearly central to understanding community structure and dynamics. In extreme cases a top predator may prey on an intermediate predator and on a shared prey. This situation is common in both aquatic and terrestrial systems. Holt and Polis (1997, Am. Nat. 149:745-764) have argued that, for coexistence to be possible, the intermediate predator must be the more efficient consumer of the shared prey, and the top predator must gain significantly from consumption of the intermediate predator. We focus here on the implications of adaptive behavior by each of the three species in such interactions. In our model, the top predator distributes effort between feeding on the other two species, the prey distributes its effort between defense against each of the predators, and the intermediate predator distributes its effort between feeding on the prey and defense against the top predator. We determine conditions for coexistence and obtain equilibrium densities and optimal distributions of effort for a range of ecologically plausible situations. We then compare our findings with previously published results and propose testable hypotheses for future empirical work. (Session 23: Predator/Prey III; Tues. 11:10-11:30am; Rooke)
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P14 FACULTATIVE SEX RATIO ADJUSTMENT FOLLOWING AN EPIDEMIC.
*P. M. Nolan, K. J. McGraw, A. M. Stoehr, A. A. Ford & G. E Hill
Dept. of Zoology, Auburn University, AL 36849 (nolanpm@mail.auburn.edu)
Fisher proposed that when sons and daughters are equally costly to produce, the equilibrium sex ratio should approximate one male per female. Trivers & Willard offered the modification that investment in offspring of each sex should be equal and that the more costly sex should be produced in smaller numbers. For instance, one or two large sons may be produced instead of several smaller daughters. Alternatively, if the offspring are likely to be of low quality because of the parent's ill health or poor territory quality, the best strategy may be to produce daughters that will yield at least some grand-offspring. In 1996, an epidemic of mycoplasmal conjunctivitis disproportionately killed male house finches (Carpodacus mexicanus), shifting the sex ratio in the 1997 breeding season from male- to female-biased. Because house finches are socially monogamous, this shift increased the likelihood that even low-quality males would be assured of an opportunity to breed. We found that of 206 chicks produced in our population, 120 were male and 86 were female, differing significantly from a 1:1 sex ratio. (Founders Award poster; Sun. eve; Terrace)
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P73 INDICES OF AFFILIATION DURING REUNION OF FAMILY MEMBERS IN CAPTIVE ORCA WHALES
*M. Noonan, L. Chalupka, M. Conners, K. Pastwick, M. Viksjo & D. Perri
Canisius College, Buffalo, NY 14208; Marineland of Canada (noonan@canisius.edu)
Documenting the degree to which mothers and offspring preserve maternal recognition over time is important in understanding the maintenance of social relationships among killer whales. This study measured the degree of recognition evidenced by mother-offspring pairs when reunited. For husbandry reasons, two female killer whales were housed apart from their two respective offspring while the young were between 1 and 2 years of age. Upon reunion, the degree to which maternal/offspring recognition occurred was assessed using four indices of affiliation: reciprocal touching, breath synchronization, inter-whale distance, and motion synchronization. Observations for each mother/offspring pair were compared with observations for the two non-related pairs. While our findings show clearly that these reunions were peaceful and largely amicable, we found little evidence to suggest that either mother specifically affiliated with its own young or vice versa. This information is relevant in considering the mechanisms underlying social bonds in this species and the time course over which they are maintained. (General Posters; Sun. eve; Terrace)
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P74 SELECTIVE ATTRITION DURING SONG DEVELOPMENT IN SONG SPARROWS
*J. Cully Nordby & M. D. Beecher
Department of Psychology, University of Washington, Seattle, WA 98195 (nordby@u.washington.edu)
Several species of oscine songbirds have been shown to sing more song material during their plastic song phase than they have in their final song or repertoire. We investigated this process of song overproduction and selective attrition during song development in a wild population of song sparrows (Melospiza melodia), a song repertoire species (each male has eight song types on average). To investigate why males selectively retain certain songs and drop others, we first identified each male s song tutors and compared both his plastic and crystallized repertoires to those of the adult males who were present during the bird s first year. We tested two predictions. First, that a young male would tend to drop songs that he learned from tutors who failed to survive the winter. Second, we compared the young male s plastic and crystallized repertoires to the repertoires of his first-breeding season neighbors (who may or may not be his natal-year song tutors) and tested whether the young male would keep those songs he shares with his neighbors and drop those that he does not. (General Posters; Sun. eve; Terrace)
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2 THE RESPONSE OF MOSQUITOFISH (GAMBUSIA AFFIINIS) TO CHEMICAL STIMULI FROM INJURED HETEROSPECIFICS
Shawn E. Nordell
Department of Biology, California State University, Northridge, CA 91330-8303 (shawn.nordell@csun.edu)
Predation is an important component of the life history and behavior of many fish. In some species of teleost fish, conspecifics respond to chemical stimuli from injured conspecifics by displaying a fright response, such as increased cohesion of schooling. The purpose of this experiment was to investigate whether mosquitofish (Gambusia affinis) display a fright response when exposed to a filtered extract made from wounded heterospecifics, guppies (Poecilia reticulata). The schooling behavior of mosquitofish was observed for ten minute periods for each of three treatments: baseline treatment (no substances added to the aquarium water), sham treatment (distilled water added to the aquarium water), and alarm treatment (fish extract added to the aquarium water). Mosquitofish responded with a fright reaction when exposed to a filtered extract prepared from wounded guppies; the fish swam in a more cohesive school during the alarm treatment than they did in either the baseline or sham treatments. The response of mosquitofish to an extract from wounded heterospecific species, guppies, indicates that the fish extract is recognized by heterospecifics. This may indicate the use of chemical alarm cues which may function to enhance predator detection may be more widespread throughout this family than previously thought. (Session 1: Communication I; Sun. 2:10pm; Forum)
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Fellows Lecture Weds. 8:30am
Coleman Hall

Fellow: ON THE FUNCTION AND EVOLUTION OF BIRD SONG: NEW QUESTIONS TO OLD ANSWERS
*Stephen Nowicki
Department of Zoology, Duke University, Durham, NC 27708 (snowicki@duke.edu)
Bird song is thought to have two primary functions. As a signal to males, song serves to repel potential rivals from the territory; as a signal to females, song serves to attract potential mates and stimulate their courtship. Convincing evidence in support of both these functions has been obtained from a wide variety of species. Less well understood is how receivers of this signal, both male and female, have been selected to respond differently to different kinds of song. For example, evidence suggests that repertoires of song types function more effectively in both territory defense and mate attraction, but it is not clear why males or females should respond differently to multiple song types as compared to a single song. In this lecture I will summarize what is known about how male and female response varies with different features of song and then examine selective mechanisms that might underlie the evolution of these responses. My focus will be to ask if and how features of a male's singing behavior convey reliable information that could explain the evolution of receivers' responses.
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110 COLLEGE-LEVEL ANIMAL BEHAVIOR EDUCATION IN A ZOO SETTING
Joanne Oliva-Purdy
Baltimore Zoo, Druid Hill Park, Baltimore, MD 21217 (jopbaltzoo@aol.com)
Scientific professionals, in zoos and elsewhere, can teach scientific methodology to students in the engaging atmosphere of the zoo.educational opportunities involving animal behavior research at zoos are parsed into four general categories based on supervision by zoo staff or college faculty and the goals of research or education. Opportunities involving on-grounds zoo research, supervised by zoo staff or by college faculty, include research assistantships, college courses, and independent studies. Both college students and graduates, some with full time jobs, participate in animal behavior research at the Baltimore Zoo, often to help with career choice or advancement. During their 2-month or longer stay, they gain experience with one or more species and observation techniques by doing assigned observations and data summarizing. Some long-term volunteers have been involved in all stages of the research process. Interns assume added responsibilities such as supervising other observers. The experience volunteers gain in conducting research helps them focus their career goals, more than class work would. Previous volunteers now hold positions here and at other animal facilities, or have pursued additional education in related areas. (Session 21: Education Symposium; Tues. 11:30-11:50am; Forum)
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P75 MULTI-MODAL COMMUNICATION IN INTERSPECIFIC HYBRID WOLF SPIDERS
Melissa Orr & *George W. Uetz
Dept. of Biology, University of Cincinnati, Cincinnati, OH 45221 (uetzgw@email.uc.edu)
This study investigates the importance of multi-modal signaling in two sympatric spider ethospecies to determine courtship cues necessary for species recognition in females. The wolf spiders Schizocosa ocreata and S. rovneri use distinct multi-modal courtship behavior containing both visual and vibratory components. Cue isolation experiments indicate that the visual courtship component appears primary for S. ocreata and the vibratory component appears primary for S. rovneri. Mate recognition errors increased when females were exposed to heterospecific males in their secondary mode of communication alone. Interspecific hybrids perform a courtship display containing key elements of both parental species. When females were presented with hybrids in cue isolation experiments, results differed. Female S. ocreata and S. rovneri exhibited intermediate levels of receptivity (50-55%) to hybrids when multiple cues were present, but receptivity varied (20-52%) when communication modes were isolated. Hybrid females had lower responses to courting males overall, but especially hybrid males. This study suggests that there is potential for natural hybridization under conditions where one mode of communication is absent, however, backcrossing would likely eliminate hybrid types. (General Posters; Sun. eve; Terrace)
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P15 WHY DO FEMALE COLORADO POTATO BEETLES (LEPTINOTARSA DECEMLINEATA) MATE WITH MULTIPLE MALES?
*Damon M. Orsetti & Ronald L. Rutowski
Department of Biology, Arizona State University, Tempe, AZ 85287-1501 (d.m.orsetti@asu.edu)
Polyandry has long been a puzzle for evolutionary biologists. Females pay a cost for mating multiple times yet this behavior is relatively wide spread. For polyandry to spread or be maintained in a population it must have a large enough benefit to offset the costs. Hypothesized benefits are generally placed in two broad categories: material benefits and genetic benefits. Relatively little research, however, has given clear evidence for the benefits of polyandry. We conducted two experiments to test the hypotheses using the Colorado potato beetle (Leptinotarsa decemlineata), a highly polyandrous animal. Both experiments mated groups of virgin females to a variable number of virgin males. During the first experiment, we assessed fecundity by isolating females after mating. We then scored egg production and larval hatching for thirty five days as well as hatch percentage for each egg batch. During the second experiment, we estimated sperm number transferred to females by isolating and freezing the female one hour after the last mating. We then removed her spermatheca and counted the sperm it contained. Results will be discussed in relation to both the material benefit and genetic benefit hypothesis. (Founders Award poster; Sun. eve; Terrace)
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89 PAINTED FACES: A COMPARATIVE STUDY OF FACIAL COLORATION IN CARNIVORES.
Alessia Ortolani
Animal Behavior Graduate Group, University of California, Davis, CA 95616 (aaortolani@ucdavis.edu)
Visual communication and camouflage are two main adaptive functions of animal coloration. However, the adaptive significance of most mammalian color patterns is still largely unknown. Using the comparative phylogenetic method, this study predicts the main function of the facial color markings present in 200 terrestrial carnivore species. I examine eight facial patterns: eyerings, eye patches, facial stripes, nostril spots, muzzle, chin, head and front ears. First, I reconstruct the number of independent evolutionary origins for each color pattern over a composite carnivore phylogeny. Second, I test the correlated evolution of each facial color pattern with specific behavioral ecological variables associated with the patterns' visibility in the environment. The results indicate that white facial markings are associated with nocturnal activity and living in closed habitats suggesting that visual communication is their main function. Dark markings around the muzzle and the head are associated with diurnal activity and open habitats suggesting that they might be used for communication. In contrast, dark markings around the eyes are associated with variables suggesting that camouflage is their main function. (Session 17: Allee Award session; Mon. 4:10pm; Forum)
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185 DYNAMICS OF REPRODUCTION IN A FRUIT FLY: DO OVARIES LEARN?
*Daniel R. Papaj, Henar Alonso-Pimentel & Anja Lachmann
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721 (papaj@u.arizona.edu)
Balancing risks of egg and time limitation is considered to be a driving force in the evolution of reproductive behavior. The same balancing of risks presumably shapes patterns of ovarian development, including sensory cuing of ovarian development by resources required for juvenile survival. Here we describe experiments defining the role of the host resource in oogenesis in a walnut-infesting tephritid fly, Rhagoletis juglandis. Females caged from eclosion with host fruit harbor more eggs sooner than control females. Assays using artificial fruit models show that fruit shape (round) and color (yellow/green) play a role in promoting egg maturation. Detailed morphological analyses indicate that fruit stimuli slightly increase ovariole number, but increase the proportion of ovarioles with mature first and second follicles. Oosorption was not a factor. Two possible tradeoffs that might favor sensory cuing of oogenesis, survival-reproduction and dispersal-reproduction tradeoffs, are discussed in the context of walnut fly life history and ecology. Finally, the possibility that animal ovaries learn to anticipate patterns of resource abundance and quality is addressed. (Session 37: Development II; Weds. 2:10-2:30pm; Forum)
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134 A COST-BENEFIT ANALYSIS OF SOCIALITY IN A COLONIAL SPIDER PHILOPONELLA PROMINENS
T. S. Park & *Jae C. Choe
Department of Biology, Seoul National University, Seoul, Korea ( jcchoe@snu.ac.kr)
Social spiders have been found and studied mainly in tropical and subtropical regions. For the first time, however, we analyzed the costs and benefits of sociality in a temperate colonial spider, Philoponella prominens, in central Korea. Philoponella prominens exhibited seasonally facultative life history patterns, ranging from solitary to colonial living. In the field conditions, solitary and colonial individuals showed no differences in prey availability and consumption rate but significant differences in web-building cost and tenure time on the web. The risk-sensitivity model has often been used to explain the evolution of sociality in animals including social spiders. According to the predictions of the model, coloniality helps reduce the variance in food consumption rate and thus is favored when food is generally abundant. We found however that colonial rather than solitary foraging is the favored strategy for P. prominens, a temperate spicies living where prey availability is comparatively low and variable. Colonial spiders spent less energy and time for building webs by sharing communal frame lines with neighboring individuals and reproduced at higher rates than solitary ones. Web-removal experiments in the laboratory confirmed the relationship between cost reduction in web building and reproductive output. (Session 27: Social behavior I; Tues. 1:30-1:50pm; Rooke)
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98 CHARACTERISTICS OF AN ESTUARINE ALARM CHEMICAL SYSTEM: THE ROLE OF EXPERIENCE OF THE FISH, TEMPERATURE OF THE WATER, AND AGE OF THE SIGNAL IN THE RESPONSE LEVELS OF FUNDULUS HETEROCLITUS.
Kristian K. Parker
Duke University Marine Laboratory, 135 Duke Marine Lab rd, Beaufort, NC 28516 (kkp1@mail.duke.edu)
Alarm behavior in response to chemical signals from injured conspecifics is widespread in freshwater fish. This study investigated alarm behavior of adults and juveniles of the estuarine fish, Fundulus heteroclitus. Activity was determined in response to alarm signals made from conspecific extracts, and was measured by determining the time spent swimming before and after the introduction of the stimulus. The results are that: 1. Both adult and juvenile, experienced and lab-raised fish show a significant decrease in activity in response to the chemical alarm signal compared to seawater, 2. Adult F. heteroclitus show both a decrease in overall activity and a decrease in response to the alarm signal with decreasing temperature, and 3. Adult F. heteroclitus show a trend towards decreasing activity with increasing age of the alarm signal. These results demonstrate that, in a laboratory context, F. heteroclitus have an alarm chemical system with the following characteristics: 1. No experience with predators is required for F. heteroclitus to show the alarm behavior, 2. Decreasing temperature affects the level of the response, and 3. Preliminary data indicates that the age of the crude alarm chemical may initially increases the potency of the signal and suggests that enzymes are involved in producing the active component of the signal. (Session 19: Predator/Prey II; Mon. 3:50-4:10pm; Gallery)
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P76 THREE TYPES OF LIPSMACKING IN RHESUS MACAQUES (MACACA MULATTA)
*Sarah R. Partan & Rebecca Wylie
Center for Animal Behavior, University of California, Davis CA 95616 (srpartan@ucdavis.edu)
Lipsmacking is an important affiliative signal in monkeys, occurring in several different social contexts. Data based on slow-motion videotape analysis of 109 separate lipsmacks given by free-ranging rhesus macaques suggest that there are at least three distinct types of lipsmacking. Typically, lipsmacking occurs while grooming (N = 28). These lipsmacks typically have a slow rate (average = 2. 13 smacks/s) and long duration (average = 18. 16 s). Lipsmacking also occurs, however, outside of the grooming context when the animals are at a distance from each other (N = 71). This type of lipsmacking (rate = 3. 13 smacks/s) can be accompanied by head-bobbing and girney vocalizations. Least commonly, lipsmacking occurs during a behavior called muzzle-up approach usually (7/10 times) directed from an adult male to an adult female. This type of lipsmacking is very rapid (rate = 3. 48 smacks/s) and quick (duration = 1. 54 s). Additional analyses of age/sex classes and accompanying behaviors of signalers and recipients will be presented in an effort to determine whether the three types of lipsmacking serve different functions. (General Posters; Sun. eve; Terrace)
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122 FEMALE SIGNALS AFFECT MALE COURTSHIP DISPLAY IN THE SATIN BOWERBIRD
*G. L. Patricelli, J. A. C. Uy & Gerald Borgia
Department of Biology, University of Maryland, College Park, MD 20742 (gp50@umail.umd.edu)
Polygynous courtship has generally been viewed as a one-way process, involving male signaling and female acceptance or rejection. However, growing evidence suggests that female signals may play an important role in shaping the content and outcome of courtship. In the satin bowerbird, Ptilonorhynchus violaceus, we explored the effects of female crouching on elaborate male courtship display. Crouching is the slow lowering and tilting forward as courtship progresses which leads to the copulation solicitation posture. There is variation in the incidence, rate and timing of crouching among courtships and 80% of females who initiate crouching leave the bower without mating. Female crouching and male display were scored from videotapes of natural courtships and female crouching was manipulated in experiments using robotic female bowerbirds. Males were found to alter the their courtship displays in response to female crouching at different rates and times. Males may increase their attractiveness to females by adapting their displays in response to female signals and male response to female signals may affect male mating success. (Session 24: Sexual selection V; Tues. 10:50-11:10am; Olin)
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18 PARENTAL CARE IN ESTRILDID FINCHES: EXPERIMENTAL TESTS OF A COLONIZATION MODEL OF BROOD PARASITISM
*Robert B. Payne, Laura L. Payne & Jean L. Woods
Museum of Zoology & Dept. of Biology, University of Michigan, Ann Arbor, MI 48109-1079 (rbpayne@umich.edu)
To assess the success of a brood parasite with a novel host, we tested whether foster care in estrildid finches is limited to young with normal appearance and behavior. We used fostering experiments with three species, one (firefinch Lagonosticta senegala) that has a mimetic brood parasite, one (goldbreast Amandava subflava) with a nonmimetic brood parasite, and one (cordon-bleu Uraeginthus cyanocephalus) with no brood parasite. All three reared nestlings of two or more other species to fledging, and all reared the brood parasite of firefinch, the village indigobird Vidua chalybeata. Because all three species sometimes reared alien young vicariants of brood parasites, we conclude that ethological constraints of nestling appearance do not absolutely prevent colonization and brood parasitism of a new host species, although nestling mimicry may give young Vidua an advantage in parental care when resources are scarce. The experimental results are consistent with molecular genetics estimates of phylogenetic histories of colonization of their host estrildids by the Vidua brood parasites (Session 4: Parental Care I; Sun. 2:30pm; Gallery)
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10 AGONISM IN BLUE MONKEYS AS A FUNCTION OF FRUIT CONSUMPTION AND AVAILABILITY
*Karen Pazol1 & Marina Cords2
1Anthropology Department, University of Pennsylvania, Philadelphia, PA 19104; 2Anthropology Department, Columbia University, New York, NY 10027 (kpazol@sas.upenn.edu)
Forest guenons such as blue monkeys Cercopithecus mitis are highly frugivorous, but the amount of fruit in their diet varies widely on a seasonal basis. To determine whether consumption and/or availability of this preferred resource affects agonism rates, 32 adult females from two social groups were monitored over a complete annual cycle; 918 hours of focal data were collected. Most agonism (85%) occurred in the context of feeding, and aggression over fruit took place at 141% of the rate expected based on the percent of foraging time females devote to different food types. Nonetheless, monthly agonism rates did not increase with the average percent of time females spent eating fruit, fruit availability, or fruit consumption relative to availability. The finding that females were less likely to forage in proximity to others when eating fruit than when consuming other resources (p<.043), suggests that females may avoid competition by spreading out. This, and other mechanisms, will be discussed as alternatives to overt aggression for partitioning limited resources. (Session 3: Foraging I; Sun. 1:30pm; Olin)
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P77 AMOUNT OF INTRA-COUPLE DECEPTION AS RELATED TO INTERPERSONAL RELATIONSHIP LENGTH AND GENDER
*M. H. Pearson & M. H. Figler
Department of Psychology and Institute of Animal Behavior, Towson University, Towson, MD 21201 (mpearson@umpsy.ab.umd.edu)
The present study examined the relationship between the length of a romantic relationship and the amount of intra-couple deception and evaluated gender differences in amount of deception. Unmarried heterosexual couples who were currently involved in a relationship participated in the study. Deception was defined as the incongruity of responses between the couples' ratings of themselves and their partner on characteristics of a potential mate, drawing from sociobiological research. Unexpectedly, no significant correlation between relationship length and amount of deception was found; also, no significant difference between genders in amount of deception was revealed. However, females rated themselves significantly higher than males rated themselves on the characteristics. Also, males rated their partner significantly higher than females rated their partner on the characteristics. Lastly, couples who were living together showed significantly less deception than those who were not living together. These findings are interpreted from a sociobiological vantagepoint. (General Posters; Sun. eve; Terrace)
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27 MONARCH BUTTERFLIES (DANAUS PLEXIPPUS) MIGRATORY STATE IS ROBUST TO CHANGES IN ENVIRONMENTAL CONDITIONS
*Sandra M. Perez1 & Orley R. Taylor2
1Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721; 2Department of Entomology, University of Kansas, Lawrence, KS 66045-2106 (smperez@u.arizona.edu)
Throughout the fall, eastern North American monarch butterflies migrate to Mexico. The cues initiating migratory behavior are likely to be a suite of environmental factors. It has been unclear, however, whether this suite of factors was necessary for maintaining migratory behavior throughout the fall season or whether migratory condition was a state that, once triggered, remained turned on. We investigated the migration trigger hypothesis by artificially changing the environmental conditions of migratory butterflies and watching for a change in directionality upon release. We also changed the natural environmental conditions (i.e. displaced the butterflies south) and watched for a change in directionality. Both body orientation in flight and vanishing bearing were measured upon release. Migratory butterflies manipulated in both of our experimental treatment groups continued to show significant directionality, in contrast to non-migratory butterflies that showed no significant directionality. This is the first study to demonstrate experimentally that monarch butterfly migratory behavior once triggered is robust to changes in environmental conditions. (Session 6: Dispersal & Migration; Sun. 4:10pm; Rooke)
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211 CHEMICALLY MEDIATED PREDATOR-PREY INTERACTIONS IN THE WOLF SPIDER PARDOSA MILVINA AND HOGNA HELLUO
*Matthew H. Persons, Sean W. Walker, Ann L. Rypstra & Samuel D. Marshall
Department of Zoology, Miami University, Oxford, OH 45056 (personmh@muohio.edu)
Pardosa milvina reduce activity in the presence of chemical cues from a larger predatory wolf spider, Hogna helluo. We tested a possible anti-predator function of reduced activity in the presence of chemical cues from Hogna. Experiments showed Pardosa survive longer in containers with live Hogna when Hogna chemical cues are present relative to containers without predator cues. We then tested variation in Pardosa activity levels based on the diet of the predator. Pardosa moved less when placed on substrates previously occupied by Hogna fed Pardosa compared to substrates with cues from Hogna fed crickets (Acheta domesticus). Another experiment demonstrated that Hogna fed Pardosa prefer substrates previously occupied by Pardosa and Hogna fed crickets prefer substrates previously occupied by crickets when the predator is given a choice between the two substrates. Results suggest that Pardosa reduce activity in the presence of Hogna chemical cues to avoid predation and discriminate between Hogna fed different diets. Hogna are attracted to prey chemical cues associated with recent prey, suggesting that Hogna fed Pardosa may represent a greater predation threat to Pardosa. (Session 42: Predator/prey IV; Weds. 4:50-5:10pm; Gallery)
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P16 EFFECT OF PREDATOR-PREY PHYLOGENETIC DISTANCE ON THE FITNESS CONSEQUENCES OF PREDATION
David W. Pfennig
Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280 (dpfennig@email.unc.edu)
I experimentally evaluated whether the fitness consequences of predation vary with phylogenetic distance between predator and prey. In two separate experiments, I fed omnivorous spadefoot toad tadpoles (Spea bombifrons, S. multiplicata, and Scaphiopus couchii) either desiccated conspecific tadpoles or an equal mass of desiccated heterospecific prey of varying phylogenetic distance to the predator. For tests involving Spea, heterospecific prey consisted of the three spadefoot tadpole species. For tests involving Scaphiopus, heterospecific prey consisted of the three spadefoot tadpole and tadpoles of great plains toads (Bufo cognatus). I also examined which prey were preferred by Spea tadpoles. I found that the prey resulting in greatest growth and survival differed for different predator species, but that tadpoles performed best on and preferred to eat non-congeneric tadpoles within the same family as the predator. In general, prey of intermediate phylogenetic distance may provide the greatest fitness benefits to predators, possibly because increased nutritional benefits of feeding on close phylogenetic prey offset increased costs of disease transmission between predators and phylogenetically close prey. (Founders Award poster; Sun. eve; Terrace)
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46 FEMALE SPADEFOOT TOADS COMPROMISE ON MATE QUALITY TO ENSURE CONSPECIFIC MATINGS
Karin S. Pfennig
Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280 (kpfennig@pop.unc.edu)
When high-quality conspecifics resemble heterospecifics, females may be unable to engage effectively in both species recognition and mate-quality recognition. Consequently, females engaging primarily in mate-quality recognition risk heterospecific matings and females engaging primarily in species recognition risk matings with low quality mates. I examined the evolutionary consequences of this conflict between species and mate-quality recognition in spadefoot toads. I compared mate preferences and the fitness consequences of these preferences in spadefoot toad populations that did and did not overlap with congeners. In non-overlapping populations, females preferred an extreme call character resembling that possessed by heterospecifics, and they had more eggs fertilized. In overlapping populations, females preferred those call characteristics that were closest to the norm for their population, and they did not benefit from mate choice. Thus, female spadefoots appear to trade-off species and mate-quality recognition, such that those co-occurring with heterospecifics forego benefits of high-quality matings to ensure conspecific matings. These results suggest that the interaction between species and mate-quality recognition may influence mate choice decisions in important and non-intuitive ways. (Session 9: Allee Award session; Mon. 11:30am; Forum)
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92 INDIVIDUAL RECOGNITION OVER DISTANCE BY BLACK-CAPPED CHICKADEES
*Leslie Phillmore1, Chris Sturdy1, Leanne Blanchard2 & Ron Weisman2
1Department of Psychology, Queen's University, Kingston, ON K7L 3N6; 2Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1 (philly@psyc.queensu.ca)
Individual recognition in songbirds has been demonstrated by playback studies in the field (neighbour-stranger discriminations) and in laboratory studies (using operant procedures). However, recognition over distance has not been formally addressed, although it seems an intrinsic part of the neighbour-stranger paradigm. We used male black-capped chickadee songs and female zebra finch distance calls recorded over several distances as stimuli in an operant discrimination with black-capped chickadees to see if first, they could discriminate among individuals recorded at 5m, and second, if they could transfer this learning over distances (25m, 50m, 75m). Discrimination of individuals was eventually learned by most birds, but transfer to distances greater than 25m was problematic. In a second test of transfer, we reversed reinforcement contingencies of the discrimination. We found that birds transferred learning to 25m recordings. Our results show that birds can learn to discriminate among several conspecific and heterospecific individuals, and can transfer that recognition to a farther distance. (Session 18: Communication V; Mon. 3:30-3:50pm; Rooke)
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P78 WHO CONTROLS FOOD RATIONS IN GREAT EGRET BROODS: FATHERS, MOTHERS, NESTLINGS?
*Bonnie J. Ploger, Matthew Medeiros & Emily Emond
Biology Department, Hamline University, St. Paul, MN 55104. (bjploger@piper.hamline.edu)
In siblicidal species, including great egrets (Casmerodius albus), the first-hatched brood-members generally secure far more food than do their juniors. This feeding advantage could result from seniors gaining dominance over their juniors by attacking them. Alternatively, this advantage could be caused by favoritism by one or both parents. We investigated these possibilities by comparing how fathers and mothers apportioned food to their offspring when chicks were free to fight versus when they were separated by a plexiglass barrier that prevented fighting. When free to fight, dominant nestlings received significantly more food than their subordinates. When separated, males did not feed dominants preferentially. Females, however, tended to deliver the most food to the beta and the least to the alpha chick in the dominance hierarchy. Parents delivered similar total amounts of food to their broods when chicks were free and when they were separated, suggesting that the plexiglass barriers did not cause parents to radically alter their feeding behavior. (General Posters; Sun. eve; Terrace)
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73 NATURAL OCCURRENCE OF BROKEN VOCAL SYNTAX IN FOUR SONGBIRD SPECIES: EVIDENCE FOR PERFORMANCE LIMITS ON TRILL RATE EVOLUTION?
J. A. Podos
Department of Ecology and Evolution, Rm. 310 Biological Sciences West, University of Arizona, Tucson, Arizona 85721 (jpodos@u.arizona.edu)
Recent song learning experiments in the swamp sparrow (Melospiza georgiana) have revealed that young birds, when exposed to song models with artificially increased trill rates, sometimes develop copies with an atypical broken syntax, in which short bursts of syllables are separated by silent gaps. Broken syntax in swamp sparrows appears to result from limits on birds' abilities to quickly manipulate their syringeal, respiratory, and/or vocal tract motor systems during sound production. In this talk I introduce evidence that a similar form of broken syntax occurs in the wild, albeit rarely, in four other emberizid species which normally produce continuous trilled syntax: Spizella passerina, Pooectes gramineus, Geospiza fortis, and Certhidae olivacea. Songs with broken syntax across these species express some common features; for example, baseline trill rates within broken syntax songs are among the highest expressed within each species, and pause durations within broken syntax songs are relatively uniform. These commonalities suggest a homologous constraint on trill production across these species. (Session 14: Communication IV; Mon. 1:50-2:10pm; Rooke)
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87 WHY WAVE? THE FUNCTION OF FIDDLER CRAB CLAW WAVING
Denise S. Pope
Department of Zoology, Duke University, Durham, NC 27708 (poped@naos.si.edu)
Many territorial advertisement signals are thought to have a dual function; both repelling rivals and attracting mates. The claw waving display of sand fiddler crabs (Uca pugilator) is commonly assumed to be one of these dual function signals since it is performed by males defending mating burrows. I tested the hypothesis that the waving display is a signal to both males and females by investigating whether both sexes were equally likely to evoke waving behavior, and were equally responsive to the display, thus assessing the function of the signal from the perspective of both sender and receiver. By manipulating the social context of male crabs, I show that they wave significantly more in the presence of females than males. By presenting both males and females with video of displaying and non-displaying males, I demonstrate that the display significantly affects the behavior of females, but not that of males. These results indicate that, from both the sender's and receiver's perspective, the claw waving display of U. pugilator functions primarily as a signal to females, and that we should be wary of assuming a signal has a dual function in the absence of experimental evidence. (Session 17: Allee Award session; Mon. 3:30pm; Forum)
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11 ECOLOGICAL TRADE-OFFS OF NOCTURNAL HYPOTHERMIA IN WINTERING SMALL FOOD-CACHING BIRDS: A DYNAMIC MODEL
*Vladimir V. Pravosudov & Jeffrey R. Lucas
Department of Biological Sciences, Lilly Hall, Purdue University, West Lafayette, IN 47907 (vladimir@bilbo.bio.purdue.edu)
During the winter, many resident bird species must survive harsh conditions of unpredictable food, low ambient temperature and long nights. Many bird species living in temperate zone can utilize nocturnal hypothermia which allows them to save up to 30% of their energy expenditure at night. However, hypothermia is not universally employed; some birds in the lab exhibit hypothermia only if they have been starved. Thus, the data suggest that there must be a cost to hypothermia, most likely the risk of predation at night. It appears that a bird is faced with several potential trade-offs that should dictate its use of hypothermia: it can avoid the cost of hypothermia by gaining fat to decrease risk of starvation but this increases energetic costs and risk of predation during the day; it can maintain lower fat reserves and use hypothermia at night, but this increases the risk of nocturnal predation. We used a dynamic model to investigate these trade-offs and how the use of nocturnal hypothermia changes energy management tactics in birds. (Session 3: Foraging I; Sun. 1:50pm; Olin)
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219 HERRING GULL FEMALES SHOW EXTREMELY HIGH LEVEL OF MATE FIDELITY
*James S. Quinn, J. S. Lauder, & C. L. Yauk
Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1 (quinn@mcmaster.ca)
Colonial living carries potential opportunities for extra-pair fertilisations (EPFs). Male herring gulls apparently guard their mates. Nonetheless they do not do so constantly, even during the period of egg fertilisation. We examined the efficacy of apparent mate guarding behaviour by examining the paternity of 927 nestlings from 10 different colonies (9 in the Great Lakes, 1 in the Bay of Fundy). The rate of extra-pair fertilisation is below 0.5% of nestlings. Despite apparent opportunities, females very rarely facilitate EPFs. Newly hatched young are unable to thermoregulate and require brooding and constant attendance during the first week or so of life. Additionally they must be fed, thus a second care giver is needed. The rarity of EPFs suggests the possible risk that mates of unfaithful females would withhold paternal care. It appears unlikely that behaviour previously interpreted as mate guarding does, in fact, serve to prevent extra-pair fertilisations. The common lapses in mate guarding, despite strict monogamy, suggests another function for attentive behaviour by males during the fertile period. (Session 44: Reproduction and mating; Weds. 4:30-4:50pm; Olin)
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174 MATE RECOGNITION IN THE SNAPPING SHRIMP ALPHEUS HETEROCHELIS
*N. Rahman, D. W. Dunham & C. K. Govind
Department of Zoology, University of Toronto, Toronto, Ontario M5S 3G5, Canada (nrahman@zoo.utoronto.ca)
The snapping shrimp Alpheus heterochelis is usually found in male-female pairs. We tested mate discrimination between former mates and unknown conspecifics. Cohabiting pairs in the laboratory were separated and then subsequently repaired with either their former mate or an unfamiliar conspecific of the same size as the former mate. Initial, distant responses to these two classes of introduced conspecifics by the focal animal was indistinguishable. These were probably mediated by visual information. However, close encounters were very different, indicating that the focal animals were clearly discriminating between former mates and strangers. Close encounters consist of intensive mutual antennal - body contact between the pair. This stage in pair establishment is probably mediated by contact chemical and / or tactile information, possibly incorporating an individual signature. Work is in progress to determine whether one of these two sensory channels is more important than the other in mate recognition. (Session 34: Mechanisms III; Weds. 11:30-11:50am; Gallery)
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P17 FEMALE-FEMALE COMPETITION FOR MATES AND SOCIAL RANK IN BLACK-CAPPED CHICKADEES
*S. M. Ramsay & L. M. Ratcliffe
Department of Biology, Queen s University, Kingston, K7L3N6, Canada (ramsays@biology.queensu.ca)
Female-female competition is predicted to occur in socially monogamous species when males vary in quality and females display mate choice. This combination results in an effective female-biased operational sex ratio. In black-capped chickadees (Poecile atricapillus), females divorce low rank males in favour of high rank males when the opportunity exists, and in the absence of those opportunities will obtain extrapair fertilisations from neighbouring high rank males. Further evidence suggests that pairing is 95% assortative by social rank and females mated with high rank males experience enhanced reproductive success. We sought to determine the factors that make females successful in competition for high rank partners and high social rank for themselves. We tested two hypotheses of partnership formation in field experiments and three hypotheses of social rank acquisition using captive pairs of unfamiliar females. The field experiments supported the resource holding potential hypothesis, and post hoc analysis showed that winners were in better condition. In the lab experiment we found support for the owner/intruder hypothesis suggesting a seniority rule for rank establishment. (Founders Award poster; Sun. eve; Terrace)
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180 EFFECTS OF FOOD SUPPLEMENTATION ON MATE GUARDING BEHAVIOUR IN EASTERN BLUEBIRDS
*M. K. Rathburn & P. A. Gowaty
Institute of Ecology, University of Georgia, Athens, GA 30602(rathburn@arches.uga.edu)
We investigated how food supplementation affected mate guarding behaviour of two populations of Eastern bluebirds, Sialia sialis, in geographically similar sites, Athens, GA and Clemson, SC. Previous simultaneous studies demonstrated that these populations differ in productivity and behaviour, perhaps because of differences in food resources. These studies and the Constrained Female Hypothesis, CFH, (Gowaty 1996) suggested that under food supplementation male mate guarding of fertile females would differ between populations. The CFH predicted that in comparison to controls, supplemented females in Athens would be guarded less by their mates, while in Clemson, supplemented females would be more strongly guarded than control females. At randomly assigned nests, we broadcast live crickets daily during the fertile period. We observed females, recording variables consistent with mate guarding behaviour. Clemson males guarded supplemented females more than control females. We found no effects of supplementation in Athens. Our results from Clemson indicate that food resources affect mate guarding. In Athens, fire ants, Solenopsis invicta, may result in bluebirds being unable to reach a threshold where behaviours are altered. (Session 36: Sexual selection VI; Weds. 10:30-10:50am; Olin)
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15 MOTHER-OFFSPRING INTERACTIONS AND SOCIAL BEHAVIOR IN TAILLESS WHIPSCORPIONS
Linda S. Rayor & Benjamin Larsen
Department of Entomology, Cornell University, Ithaca, NY 14853 (lsr1@cornell.edu)
Social behavior and extended maternal interaction with offspring is extremely rare among arachnids. Here we report for the first time extensive affiliative behaviors among mother and offspring tailless whipscorpions (Arachnida: Order Amblypygi: Phrynus marginemaculata). The first pair of legs of these fast, non-visual, tactile predators are modified into antenniform whips three times their body length. Mothers give birth to ~18 offspring, which cling to her abdomen through the first instar. From the 2nd through the 4th instar in captivity, young remain in groups of 4-10 individuals around the mother or in close contact with one other. Mothers and offspring mutually stroke each others whips and pedipalps in greeting. Young orient to the adult female and initiate pedipalp to pedipalp contact. Non-kin young are immediately accepted into the social group. Prey is not shared, nor is prey stolen by larger individuals. Adults are found in loose colonies. These affiliative behaviors are indicative of complex sociality typical of only the most social spider species, and extend social behavior into a new Order. (Session 4: Parental Care I; Sun. 1:30pm; Gallery)
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138 REPRODUCTIVE INCENTIVES IN SOCIAL WASPS
*H. Kern Reeve, Philip T. Starks, John M. Peters & Peter M. Nonacs
Section of Neurobiology and Behavior, Cornell University, Ithaca, New York, 14853-2702 (hkr1@cornell.edu)
Recent evolutionary models of reproductive partitioning within animal societies (known as optimal skew, concessions, or transactional models) predict that a dominant individual often will yield some fraction of the group s reproduction to a subordinate as an incentive to stay in the group and help rear the dominant s offspring. These models quantitatively predict both (i) the conditions under which a dominant yields such a staying incentive and (ii) the exact magnitude of this incentive, each as a function of the genetic relatedness between dominant and subordinate, the overall expected group output, and the subordinate s expected output if it breeds solitarily. We report that this theory of reproductive incentives predicts with remarkable accuracy the observed reproductive partitioning between co-nesting dominant and subordinate queens in the social paper wasp, Polistes fuscatus. In particular, the theory correctly predicts that (i) reproductive sharing occurs, (ii) the dominant s share of reproduction, i. e. the skew, increases as the colony cycle progresses, (iii) the skew is positively associated both with the colony s productivity and with the relatedness between dominant and subordinate, and (iv) the exact magnitudes of the skew. Thus, our results provide the strongest quantitative support yet for a unifying model of social evolution. (Session 27: Social behavior I; Tues. 2:50-3:10pm; Rooke)
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P79 ALARM REACTIONS OF GOLDEN SHINERS (NOTEMIGONUS CRYSOLEUCAS) TO VISUAL, CHEMICAL, VIBRATIONAL, THERMAL AND COMBINED STIMULI
Bradley G. Rehnberg
Department of Biology, York College, York, PA 17405 (brehnber@ycp.edu)
Fish respond to sensory inputs in ways that are dependent upon context and the specific nature of the stimulus. Many stimuli can be considered frightening or alarming to fish and they elicit avoidance or escape behaviors. My research objective was to assess the possible overlap of alarm behaviors across various categories of alarming stimuli. Does a single species of fish have a single stereotypic behavioral response for all categories of alarming stimuli? Or, alternatively, do fish display alarm behaviors that are unique and narrowly appropriate for each category of alarm stimulus? Groups of 10 golden shiners Notemigonus crysoleucas were videotaped while being presented with single stimuli in 210 L tanks. The test stimuli included two odors (L-alanine or alarm pheromone), an acoustico-lateralis disturbance, a sudden change in water temperature, a visual model of a predator, and a living predator. Observations and data analysis indicated that each stimulus elicited a unique behavioral response. Responses were complex, however, and behavioral components such as C-turns, increased group cohesion, flash expansion, bottom orientation, and others were seen in reactions to more than one stimulus. (General Posters; Sun. eve; Terrace)
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125 Education Projects at the Animal Behavior Society
Michael J. Renner
Department of Psychology, West Chester University, West Chester, PA 19383-2112 (mrenner@wcupa.edu)
The Animal Behavior Society is currently engaged in several projects to support and enhance education about animal behavior. Through its Education Committee, ABS has made substantial changes to the education section of its web site, including establishing an online image library of graphics for use in teaching. At this meeting, the committee will initiate a project to develop resources for teachers of pre-college students. These projects will be discussed, and members will have the opportunity to become involved, including suggesting additional education projects that ABS might pursue. (Session 25: Education Symposium; Tues. 1:30-1:50pm; Forum)
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P80 PSYCHOPHYSICS FOR AMATEURS: VISUAL DISCRIMINATION PROBLEMS AS ENVIRONMENTAL ENRICHMENT FOR POLAR BEARS (URSUS MARITIMUS)
*Michael J. Renner, Jennifer G. Plebani, Aislinn L. Kelly, Christopher T. Cuppels, Jeanna Stabinski & Jonathan R. Janiszewski
Department of Psychology, West Chester University, West Chester, PA 19383-2112 (mrenner@wcupa.edu)
Although there are numerous conflicting anecdotal reports concerning polar bear (Ursus maritimus) vision, there is no scientific evidence concerning whether the bears have color vision. We report on studies of color discrimination, conducted both as part of a program of environmental enrichment procedures for large mammals, and to study the cognitive capabilities of the bears. The subjects are two unrelated 18-year-old females. Following collection of extensive baseline location and behavior data, small ice blocks of different colors are thrown into the enclosure in pairs, 6-12 trials per session, 1-3 sessions per week. One color contains a food treat; the other color is empty. Measures to control confounds such as olfactory cues will be reported. The initial ~100 trials are inconclusive, but suggest that the bears may discriminate reliably on land but not in water. At a broader level, these problem-solving exercises increase the bears' activity levels, both during trials and after completion. Preliminary data suggest that play behavior may be especially affected. The use of discrimination problems can give the bears an ongoing series of problems to solve, including reversal and generalization tests, providing continued stimulation. Data collection is ongoing, and more complete results will be reported. (General Posters; Sun. eve; Terrace)
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P81 IDEAL FREE DISTRIBUTION IN HIMANTOPUS MEXICANUS ?
*Alejandro Ríos Chelén, José Luis Osorno & Constantino Macias Garcia
Inst. de Ecología, Dept. Ecol. Evol. UNAM. AP. 70-275 CP. 04510 (aarios@miranda.ecologia.unam.mx)
Understanding the distribution of animals is interesting for both theoretical and applied reasons. We assessed whether in the black-necked stilt, Himantopus mexicanus, the net gain rate decreases while the number of competitors increases and whether the mean gain rate is equal in different patches (Interference Model, Sutherland 1983). Four patches in the Parque Ecológico de Xochimilco, were designated for the study. Water and ground samples were taken to assess the invertebrate´s concentration. To know the individual intake rate and the number of competitors, focal and scanning observations were done. The net gain rate was calculated as Gi=Qi/nim. As the number of individuals increased the net gain rate decreased and in average, the net gain rate was the same in all patches. Although the interference model seemed to describe the distribution of the black-necked stilt, it is necesary to measure the individual competitive skills and to register the individual localization between patches in order to determine whether or not a truncated distribution is ocurring. (General Posters; Sun. eve; Terrace)
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P82 PHEROMONES IN SPIDER SILK: THE IMPORTANCE OF CHEMICAL COMMUNICATION
*Jefferson A. Roberts & George W. Uetz
Dept. of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221-0006 (roberjr@email.uc.edu)
The silk of wolf spiders (Lycosidae) often contains pheromones and serves a critical function in communication. This research concerns chemically-mediated recognition in sympatric wolf spider ethospecies (Schizocosa ocreata and S. rovneri) behaviorally isolated by differences in male courtship communication. Males of both species court conspecific and heterospecific females and their silk with equal frequency, but may vary in courtship intensity. Here, we address questions about male recognition of conspecific/heterospecific female chemical signals: 1) does male courtship behavior vary with pheromone stimulus; 2) does the pheromone content of female silk vary with reproductive status? Male S. ocreata show decreased courtship with washed female silk, and increased responses to extract alone (compared to untreated silk and blank controls), suggesting that males recognize chemicals in silk. However, male responses to conspecific and heterospecific silk and pheromone extracts were similar. Additionally, males respond to the silk of conspecific virgin females of reproductive age with greater frequency than the silk of juvenile or mated females. Results provide evidence for the importance of chemical communication in a well-studied spider model system. (General Posters; Sun. eve; Terrace)
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103 HIGH LAST MALE SPERM PRECEDENCE AS A POSSIBLE EXPLANATION FOR MATE GUARDING IN A DIURNAL FIREFLY
*Jennifer Rooney & Sara M. Lewis
Department of Biology, Tufts University, Medford, MA 02155 (jrooney@emerald.tufts.edu)
In some nocturnally active fireflies, males transfer nutritious spermatophores to females during copulation, and recently, this behavior has also been observed in a diurnally active species, Ellychnia corrusca. Although morphologically similar to some diurnal fireflies, E. corrusca adults have a much longer lifespan and are thought to communicate chemically. Copulation durations in this species can last up to 22 hours even though sperm and spermatophore transfer occur within 60 minutes. Previous experiments from our lab have shown that females incorporate male spermatophore-derived protein into somatic tissue and developing oocytes, reaching a maximum at 96 hours after mating. We hypothesized that last male sperm precedence would be high in this species and would be highest in eggs laid 96 hours after mating. Using RAPD-PCR to amplify polymorphisms in nuclear DNA, we were able to assign parentage to hatched larvae. We determined that last male sperm precedence in this species is on average 84% and that sperm precedence increased as days after mating increased. The high number of fertilizations gained by the last mating male might be an explanation for the extremely long mate guarding durations in this species. (Session 20: Sexual selection IV; Mon. 3:50-4:10pm; Olin)
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124 THE EVOLUTION OF A COMPLEX COURTSHIP RITUAL VIA SEXUAL CONFLICT
*Jennifer A. Sadowski & Allen J. Moore
Center for Ecology, Evolution, & Behavior, University of Kentucky, Lexington, KY 40506-0225 (jen@ceeb.uky.edu)
In many mating systems, males possess elaborate traits (morphological and behavioral) that are crucial to mating success via female discrimination. The striped ground cricket, Allonemobius socius, has a long and complex courtship ritual which includes a variety of male behaviors (various types of acoustic calls and nuptial gifts) and requires female responses to these behaviors for successful mating. The possibility for sexual conflict therefore exists. We examined the effects of male and female condition, male and female body size, and male nuptial gift sizes (spermatophore and tibial spur size) on the duration of courtship sequences which were controlled by either sex. We found condition of both sexes affected the rate of progression of some mating sequences and females initiated mating faster with larger males with larger nuptial gifts. We also examined the quantitative genetic basis of male and female morphological and behavioral traits. Our results suggest that females win the conflict between the sexes and traits important in sexual conflict may have a heritable basis. (Session 24: Sexual selection V; Tues. 11:30-11:50am; Olin)
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P83 ASYMMETRIES IN SIZE AS PREDICTORS OF COMPETITION OUTCOMES IN NICROPHORUS
*Sandra A. Safryn & Michelle Pellisier Scott
Department of Zoology, University of New Hampshire, Durham, NH 03824 (ssafryn@cisunix.unh.edu)
Burying beetles (Nicrophorus) utilize small carcasses as a food source for raising their young. Since these carcasses are valuable but also limited and unpredictable, they set the stage for intaspecific competition. When two male beetles discover a female with a carcass they compete for ownership. The asymmetry of size has been correlated with fighting ability and with the outcomes of these competitions. This study investigates whether pronotal width or body mass is a better indicator of size and predictor of the outcome of these conflicts. Contests between two males for a female and a 25 -30 gram carcass were conducted in the laboratory. Male pairs consisted of beetles with either different pronotal widths and equal weight (pronotal-width asymmetry) or beetles with different weights and equal pronotal width (mass asymmetry). If an asymmetry in fighting ability exists, the determination of dominance should not be random. The outcomes of competition between males with pronotal-width asymmetries were significantly different than random (n=15, p=0.04) favoring beetles with wider pronotums. Whereas the outcomes of conflicts between beetles with mass asymmetries were random (n=18, p=0.57). Thus pronotal width is a better indicator of size and predictor of the outcomes of competition between male burying beetles. (General Posters; Sun. eve; Terrace)
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64 MECHANISIMS BEHIND MATE CHOICE OF FEMALE CONVICT CICHLIDS
*N. Santangelo & M. Itzkowitz
Department of Biological Sciences, 31 Willimas Drive, Lehigh University, Bethlehem, PA 18015 (nis5@lehigh.edu)
It is well established that females of many species choose males of a larger size, but this is often related to the larger males' ability to dominate over smaller subordinates. How females distinguish between larger potential mates in the absence of these male interactions remain unclear. Convict cichlids Cichlasoma nigrofasciatum were placed in tanks in which a single female had access to two individual males that did not have contact with each other (visual or tactile). Females were expected to choose the larger of the two males, but results suggest that females are more likely to choose the larger male only when the difference between the males is of a certain size value. This value is based on the size of the female. Other results suggest that neither time spent, nor amount of visits to each male was correlated to male size differences. (Session 12: Sexual selection II; Mon. 10:50-11:10am; Olin)
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P18 ACOUSTIC AND VIBRATORY SIGNALING AND POSTCOPULATORY BEHAVIOUR IN THE COSTA RICAN KATYDID ANCISTROCERCUS CIRCUMDATUS WALKER
*Tanta Savin & Glenn K. Morris
Biology Department, University of Toronto at Mississauga, Mississauga, ON L5L 1C6 (tsavin@erin.utoronto.ca)
Ancistrocercus circumdatus is a pseudophylline katydid inhabiting leguminous trees in the tropical forests of Southern Mexico and Costa Rica. As do other Orthoptera, males utilize an extensive calling repertoire which includes acoustic (both audio and ultrasonic) and vibratory signals. Females often respond with a tremulatory signal similar to that of the male. In addition to these signals, males perform an elaborate, lengthy (up to 35 min.) postcopulatory display. This consists of several bouts (3-10) of vigorous tremulation, where the distal tip of the male's abdomen is displaced vertically by as much as 4 cm, interspaced with bouts of smaller tremulations. Preliminary analysis indicates that a male's subsequent mating success is not directly related to the presence or absence of this behaviour. This suggests that cryptic, postcopulatory female choice may occur in this species. (Founders Award poster; Sun. eve; Terrace)
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P84 SUCKLING AND EARLY SIBLING COMPETITION IN PRAIRIE VOLES, MICROTUS OCHROGASTER
*D. Kim Sawrey, Karen H. Dansky & Corey S. Novak
Department of Psychology, University of North Carolina, Wilmington, NC, 28403 (sawrey@uncwil.edu)
McGuire (1998) reported substantial nipple fidelity in prairie voles, a species with tenacious nipple clinging, on days 4-16 postpartum. We investigated nipple fidelity in pups aged 0-4 days by recording the location of individual voles four times each day. Pups were attached on 74% of all observations (N=19 litters). More pups were unattached on day 0, the day of birth, than on other days. Hind nipples were most likely to be used, followed by middle, and front nipples. Pups of 10 litters were individually weighed both early (day 0-1) and late (day 4-6) in the study. In 7 of 10 litters, the pup that was attached most frequently was also the pup that exhibited the greatest weight gain during the period. Thus, although non-nutritive suckling undoubtedly occurs, increased time spent attached may translate directly into increased weight gain. Nipple fidelity for litters of 3-5 pups (N=13) ranged between. 31 and. 42 (mean =. 37). These values are lower than those reported by McGuire and suggest that nipple fidelity may gradually emerge and increase early in development. (General Posters; Sun. eve; Terrace)
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188 TEMPERATURE AVOIDANCE BEHAVIOR OF JUVENILE AND ADULT LOBSTERS (HOMARUS AMERICANUS).
*Suzanne M. C. Schreiber, Susan A. Krull & Winsor H. Watson, II
Department of Zoology, University of New Hampshire, Durham, NH 03824 (suzanne@cisunix.unh.edu)
The lobster population of the Great Bay estuary system exhibits a skewed sex ratio of adults but an equal sex ratio of juveniles. We are examining the role of temperature in the development of this distribution pattern. Previous research (Crossin et al., 1998) shows that adult female lobsters have a lower preferred temperature than adult males. Our goal was to examine the ontogeny of the temperature response in juveniles, adolescents and adults. In this experiment, lobsters inhabiting a shelter in a flow-through water trough were exposed to increasing temperatures and times of exit were noted. These times were correlated with temperatures obtained from a datalogger attached to the dorsal carapace of the lobster. Temperatures of exit were analyzed for size- and sex-based differences. As expected, preliminary results indicate that adult males leave the shelter at higher temperatures than adult females. There is no obvious difference in temperature avoidance thresholds of juvenile males and females. Thus, the influence of temperature on behavior changes over the life of the lobster, possibly resulting in changes in distribution patterns. (Session 38: Mechanisms IV; Weds. 1:50-2:10pm; Gallery)
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72 ESTRUS INFLUENCES ON SIGNAL SENDING AND ASSESSMENT BY ASIAN ELEPHANTS
*Bruce A. Schulte1, Barbara Slade2 & L. E. L. (Bets) Rasmussen3
1Department of Biology, Providence College, Providence, RI 02918; 2Portland State University, Portland, OR, 97207; 3Department of Biochemistry & Molecular Biology, Oregon Graduate Institute, Beaverton, OR 97006 (bschulte@providence.edu)
Animal signals have evolved under selection by the physical environment, sender efficacy and receiver assessment. Even in the apparent cooperative act of courtship the sexes often differ in their objectives -- males search for quantity and females assess quality. In female Asian elephants, a sexual receptivity pheromone (Z -7-dodecenyl acetate) toward males is released in the urine commencing at the follicular stage and increasing concentration until ovulation. Captive Asian elephants exhibited greater aggressiveness and higher rates of 'tail-slapping' -- in-and-out tail movements -- during this preovulatory period; the latter action may disperse the pheromone to attract males. Wild female elephants also exhibit mate choice. Males in the rut-like state of musth are preferred and in a complementary captive study, urine from a musth male elicited the greatest chemosensory responses from females approaching ovulation. For yet unknown reasons, females frequently touch each other's genitals with their trunk tip, however females display little interest in the acetate pheromone. The description of chemosignals and sender-receiver states in which they are transmitted provide essential understanding for further investigation into signal mechanisms, functions and evolution. Elephants are proving to be an excellent model system for such studies. (Session 14: Communication IV; Mon. 1:30-1:50pm; Rooke)
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20 SEXUAL SELECTION LIMITS EVOLUTIONARY INNOVATION IN BIRD SONG
*W. A. Searcy, S. A. Nowicki, M. Hughes, & J. Podos
Department of Biology, University of Miami, Coral Gables, FL 33124 (wsearch@miami.edu)
Young male swamp sparrows (Melospiza georgiana), when tutored with songs having artificially-increased trill rates, are unable to produce the songs in their original form. Among other expedients, males copying such songs introduce silent intervals into the songs, producing a novel 'broken' syntax. Broken syntax songs are accepted as models in tutoring experiments, with the novel syntax sometimes being passed from generation to generation. Here we ask whether broken syntax songs are accepted as functional signals by adults of the species. We tested male response to songs using territorial playbacks and female response using the solicitation display assay. Results show that territorial males respond much more strongly to broken syntax songs than to a heterospecific control and do not discriminate broken syntax from normal syntax songs. Adult females also respond more strongly to broken syntax songs than to the heterospecific control, but unlike males discriminate against broken syntax relative to normal syntax in conspecific song. The results suggest that female preferences act as a conservative force, limiting innovation in the evolution of song. (Session 5: Communication II; Sun. 3:30pm; Forum)
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184 ADULT AGGRESSIVE BEHAVIOR IN MICE IS DECREASED AFTER PRENATAL IMMUNE STIMULATION.
*Eric N. Sergeant & Kathryn E. Hood
Department of Human Development and Family Studies, The Pennsylvania State University, University Park, PA 16802. (ens105@psu.edu)
We have shown that stimulation of the infant immune system reduces attacks in adult ICR male mice (Granger et al, 1996, Brain, Behavior and Immunity, 10, 249-259). Here we examine whether offspring adult social behaviors are related to changes in maternal behaviors after immune stimulation during pregnancy. On day 10 and 12 of pregnancy, pregnant ICR mice (N=28) were given 2. 5 ug LPS endotoxin (E. coli), sufficient to cause transient illness. Control dams (N=27) received vehicle only. All litters (N=53) were of normal weight and size. 30 min observations of undisturbed litters on postpartum days 2, 5, 8, 11, and 14 yielded measures of maternal handling, nursing, and licking. After weaning and isolation rearing, 45 day old males (N=53) were observed in dyadic tests. Males with prenatal stress show significantly fewer attacks than saline controls. Other behaviors (freezing, social investigation, social reactivity) show no significant effect of prenatal stress. No correlation is found between maternal behaviors and offspring adult behaviors. Prenatal stress may act to moderate social development. (Session 37: Development II; Weds. 1:50-2:10pm; Forum)
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54 TERRITORIAL BEHAVIOR IN THE WESTERN FENCE LIZARD
*Lea A. Sheldahl & Emilia P. Martins
Department of Biology, University of Oregon, Eugene, OR 97403 (lea@darkwing.uoregon.edu)
In this study, we explored the definition of territory using the western fence lizard, Sceloporus occidentalis, as a model system. Three qualifications are employed in definitions of territory: (1) do the animals utilize a fixed home range, (2) do they actively defend a majority of this home range, (3) is exclusive use of the defended areas maintained? Focal animal sampling and census techniques were employed to assess the home range and territory sizes of S. occidentalis. We operationally defined a territory as the area within which the animal was seen to give an agonistic or broadcast pushup display. Dyadic encounters were staged to assess the intensity of agonistic interactions between individual fence lizards. The lizards did exhibit site-fidelity across years, and they produced pushup displays within the majority of their home ranges; however, they also exhibited extensive home range overlap. The overlap in territory area was somewhat reduced which suggests that, despite the low occurrence of physical fighting, agonistic and broadcast pushup displays are sufficient signals for the maintenance of territorial boundaries. (Session 11: Resource Acquisition; Mon. 9:50-10:10am; Gallery)
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126 BEHAVIOR COMES ALIVE AT THE ZOO
*Daavid J. Shepherdson & Roger J. Yerke
Oregon Zoo, 4001 SW Canyon Rd, Portland, OR, 97221 (shepherdsond@metro.dst.or.us)
Reform in science education at the national, state and local level is calling for a more hands-on, inquiry based approach to the teaching of science in our schools. However significant obstacles must be overcome before this can become reality. Teachers at elementary schools frequently do not have a background in science and do not feel well qualified to teach science. Science literacy is a pre-requisite to understanding environmental issues and is therefore a priority of the Oregon Zoo's education program. The science of animal behavior provides a vivid and exciting example of the scientific process, using tools that are relatively simple and easy to use and understand. The zoo is of course is an ideal location for demonstrating and involving visitors in animal behavior studies. We have developed three programs based on the study of animal behavior in the zoo. The first two, Science: A View From the Zoo and the Zoo Summer Science Institute are aimed at K-7 teachers and help them to understand science inquiry by involving them in studies of animal behavior. The third, Zoo Watch provides visitors, including school groups, with the information and tools to conduct animal behavior observations in the zoo. Evaluation studies indicate these programs are effective. (Session 25: Education Symposium; Tues. 1:50-2:10pm; Forum)
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P85 SOCIAL LEARNING BY BLACK-CAPPED CHICKADEES
*David F. Sherry, Bruce Baxter, Kevin Johnston & Riley E. Hinson
Department of Psychology, University of Western Ontario, London, Ontario, Canada N6A 5C2 (sherry@julian.uwo.ca)
Black-capped chickadees Parus atricapillus can learn a novel feeding skill by observation of a conspecific tutor, or by exposure to environmental changes produced by a tutor. Previous results also showed that social experience with a tutor may accelerate learning, even when the tutor does not demonstrate the skill. The latter effect was investigated further in the present experiment. Naive chickadees were paired with either: 1) an experienced tutor that opened a small container of food, 2) an experienced tutor with no container to open, 3) a naive bird with no container to open, or 4) an empty cage with no other bird present. In 15 min test trials with no other bird present, chickadees in condition 1 made over 30 attempts per trial to open the container; birds in the other conditions made fewer than one attempt per trial. Sequence analyses showed that in training trials, performance of the skill by naive birds followed its performance by tutors. These results indicate that the mere presence of a conspecific - whether an experienced tutor or not - has little effect on social learning under the conditions of this experiment. (General Posters; Sun. eve; Terrace)
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158 EVEN THE LONELY: ASSESSING THE FORMATION OF SOCIAL ORGANIZATION IN A SOLITARY SPECIES
*Debra M. Shier1, Sonja I. Yoerg1 & Janet A. Randall2
1MVZ, University of California, Berkeley, CA 94707; 2Biology Department, San Francisco State University, SF, CA 94312 (dmshier@ucdavis.edu)
Solitary kangaroo rats D. heermanni use long-distance communication (footdrumming) to regulate social interactions. Females footdrummed to approaching males and juvenile males drummed to all adults (Shier and Yoerg, 1999). Footdrumming, therefore, appears related to social status. In the present study, we examined changes in social dominance and communication during 66 staged encounters (every possible pairing of 6 males and 6 females). We measured frequency, duration and initiation of fights and frequency to approach and retreat. Initial interactions between unfamiliar rats conformed to a near-linear dominance hierarchy (h=0. 88). Each pair was then familiarized in a large room then retested. After familiarization, the dominance relationships became linear (h=0. 97). Rates of footdrumming increased after familiarization, while rates of aggression decreased, suggesting that communication at a distance may substitute for aggression. Relationships between kangaroo rats appear to form rapidly, exhibit transitivity across dyads and become less aggressive after familiarization. Moreover, preliminary evidence suggests that outcomes of such paired interactions can be used to predict mating preferences. (Session 31: Social behavior II; Tues. 5:10-5:30pm; Rooke)
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139 FREQUENCY-DEPENDENT SELECTION ON MALE MATING STRATEGY AND SEX RATIO IN A MARINE ISOPOD
Stephen M. Shuster
Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011-5640, USA (stephen.shuster@nau.edu)
In Paracerceis sculpta, three male morphs coexist. Each morph is distinct from the others in behavior, body form, and genotype at a single locus, Ams (=Alternative mating strategy). Interactions between Ams and a second autosomal locus, Tfr (=Transformer), cause deviations in family sex ratio. Mating success among the male morphs varies with the number of females, and with the number and type of other males at breeding sites. If frequency-dependent selection acts on Ams-Tfr allele combinations, observed allele frequencies at Ams, multiplied by relative male mating success at breeding sites, should predict the population frequencies of the three male morphs, as well as the direction and magnitude of sex ratio biases from one generation to the next. These predictions were met in three separate data sets collected over a 12-year period. Large harems evidently allow female mimics (b-males) and sneakers (g-males) to invade populations because the average fitnesses of such males at breeding sites, while less than that of harem-holding a-males, exceed the average fitness of all a-males combined. If polygyny alone allows alternative mating tactics to invade populations, genetic polymorphisms in male mating behavior may be more common than is now believed. (Session 28: Evolution and SS I; Tues. 1:30-1:50pm; Olin)
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7 CONFLICTING DEMANDS, MULTIPLE BEHAVIORAL MECHANISMS, AND SEXUAL SELECTION II: EFFECTS OF VARIATIONS IN FOOD AVAILABILITY
*Andrew S. Sih & David E. Wooster
Center for Ecology, Evolution, and Behavior, University of Kentucky, KY 40506 (andy@ceeb.uky.edu)
Overall sexual selection on a suite of traits for males of the stream water strider, Aquarius remigis, depends on the interplay of multiple behavioral mechanisms: male-female conflict, male-male competition and female choice. To quantify the effects of these mechanisms on sexual selection, we measured individual male mating success, mating-related behavior, and morphological characters for replicate populations of water striders in experimental streams. We then used path analysis to estimate the relative importance of various pathways that correspond to the multiple behavioral mechanisms that generate sexual selection. Variation in ecological conditions should alter the behavior of individual males and females and thus the relative importance of these behavioral mechanisms. Last year, we presented the results of an experiment testing predictions on how variations in sex ratio and density influence the dynamics of sexual selection. This year, we will present results of an experiment testing effects of varying food availability on multiple behavioral mechanisms underlying sexual selection. (Session 2: Sexual Selection I; Sun. 2:10pm; Rooke)
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P86 TEMPERATURE EFFECTS ON THE ANTIBACTERIAL ACTIVITY OF ORIGANIUM OIL ON SEVERAL SPECIES OF BACTERIA
Mark Simons & *Fred B. Schnee
Department of Biology, Loras College, Dubuque IA 52004 (schnee@loras.edu)
Billing and Sherman (1998) have suggested that the ultimate cause of spice use by humans is due to its ability to limit the growth of pathogens on food. However, the use of spices as growth inhibitors is often limited because of flavor considerations. This suggests that synergistic effects are required if spices are being used as effective food preservatives. Such effects could include interactions with other spices, temperature or other factors utilized in food preparation. Origanium oil (the essential oil of oregano) was screened for antibacterial activity against a range of Gram-positive and Gram-negative bacteria using a paper disc method. At 37 degrees centigrade, origanium oil showed considerable activity against most of the bacteria tested with Psuedomonas aeroginosa exhibiting the greatest resistance. An increased susceptibility of P. aeroginosa was observed when the temperature was decreased to 25 degrees centigrade. These results suggest that, at least in some cases, spice used in conjugation with temperature in food preparation would provide antibacterial activity without decreasing the palatability of the food. (General Posters; Sun. eve; Terrace)
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25 MALE MIGRATION BETWEEN GROUPS OF LION-TAILED MACAQUES
*Mewa Singh1, Mridula Singh1 & Douglas K. Candland2
1Department of Psychology, University of Mysore, Mysore, India 570 004; 2Department of Psychology, Bucknell University, Lewisburg PA (dcandlan@bucknell.edu)
The endangered lion-tailed macaque (Macaca silenus) inhabits the rainforests of the Western Ghats in southern India. The rainforest over most of the range of this species is now fragmented and the groups of lion-tailed macaques have become isolated demes with no room for dispersal or gene exchange. There still exist populations in which two or more groups have overlapping home ranges. In such areas, we have encountered isolated, individual adult males, and recently, we have also recorded cases of intergroup male migrations. The most notable feature of such migrations is some rather marked changes in the behavior of group members, but still, an ease with which such adult male immigrations are tolerated. The finding has a significant implication for the management of wild, isolated demes in which adult males could be introduced with minimum xenophobic reactions, and the genetic diversity maintained in otherwise biologically doomed populations. (Session 6: Dispersal & Migration; Sun. 3:30pm; Rooke)
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30 SEVERAL SMALL MAMMAL SPECIES DISCRIMINATE BETWEEN RED AND WHITE OAK ACORNS: A GENERAL PHENOMENON FOR CACHING FORAGERS?
*P. D. Smallwood, Michael A. Steele & Juan Radillo
Biology, University of Richmond, Richmond VA 23173 (psmallwo@richmond.edu)
In previous work, we demonstrated that gray squirrels discriminate between acorns of the red oak and white oak subgenera in midwestern deciduous forests of North America. They preferentially store acorns of the red oak species, and eat white oak acorns immediately (or kill the acorn first, by biting out the embryo). This discrimination may affect oaks in a number of ways (e. g., differential dispersal, the rate at which each oak species colonizes new areas). These potential effects may be mitigated if other caching animals do not discriminate between the different oak groups, or if they preferentially disperse acorns of the white oak group. Conversely, if other caching animals exhibit the same caching behaviors as gray squirrels, the effects on dispersal would be enhanced. We examine other Sciurids, and Peromyscus, in eastern deciduous forests, and in other biomes. We find that other animal species have the same caching preferences as gray squirrels. (Session 7: Foraging II; Sun. 3:30pm; Olin)
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P87 DOMINANCE RANK AND REPRODUCTIVE SUCCESS IN GRAY SQUIRRELS
Janelle L. Smith1, *Kevin M. Sours1, Michael E. Pereira1, Jose E. Diaz2 and Patty E. Parker2
1Department of Biology, Bucknell University, Lewisburg, PA 17837; 2Department of Zoology, Ohio State University, Columbus, OH 43210 (kevinsours@yahoo.com)
It has been suggested that dominance rank predicts reproductive success in gray squirrels Sciurus carolinensis, but this hypothesis has previously not been supported by quantitative data. In the spring 1997 breeding season, the captive colony of gray squirrels at Bucknell University produced two litters. Offspring paternity was determined using multilocus minisatellite DNA fingerprinting using Jefferey's probe 33.15. Agonistic interactions, recorded using focal animal sampling, identified dominance hierarchies among adults (4 females; 3 males). Only the first and second ranking females produced successful litters. Both litters were sired by the top ranking male. These data suggest that both male and female reproductive success is positively correlated with dominance rank. Possible effects of captivity will be discussed. (General Posters; Sun. eve; Terrace)
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P88 NEPOTISM AND COOPERATIVE BEHAVIOR IN EASTERN GRAY SQUIRRELS
*Janelle L. Smith & Michael E. Pereira
Department of Biology, Program in Animal Behavior, Bucknell University, Lewisburg, PA 17837 (jsmith@bucknell.edu)
Unlike most tree squirrels, gray squirrels Sciurus carolinensis display feamle-biased natal philopatry. Kin retention enables protracted familial relationships which may result in either nepotistic or cooperative behavior. Such behavior may be amplified during periods of environmental stress. Agonistic and amicable interactions within a captive colony of gray squirrels were documented from February 1998 to March 1999. The colony (n=14, with two mother-offspring kin groups) resided in an outdoor enclosure (10m x 12m x5m) furnished with a network of branches connecting the 15 nestboxes. Data collection was conducted for 400 hours using a combination of ad lib, focal animal and scan sampling. During portions of this period the subjects were experimentally exposed to environmental stressers. Environmental stress was simulated by manipulating nestbox quality and introducing unfamilar squirrels into the enclosure. Nepotistic behavior is defined as relatively low levels of agonistic and elevated levels of amicable behavior amongst kin. Data suggest nepotistic behavior is amplified during stressful periods and used to secure and defend high quality nest sites. (General Posters; Sun. eve; Terrace)
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146 WHOM DO WE EDUCATE? EVERYONE!
Charles T. Snowdon
Department of Psychology, University of Wisconsin, 1202 West Johnson Street, Madison, WI 53706-1696, USA (snowdon@facstaff.wisc.edu)
For most of us education means teaching undergraduate and graduate students, but, in fact, we have a much broader customer base. If our science is to thrive, we need to communicate the significance of our work to legislators, science administrators, university administrators, the media, and the general public. We need to work effectively with pre-college students to prepare the next generation of animal behaviorists. We need to be active in training and collaborating with scientists from other countries since our work has international scope. Each of us should have ready a brief summary of the importance of our own research and that of our colleagues: what is the relevance of scientific study of animal behavior for improving the human condition? How can our work benefit the well-being of domestic animals or lead to improved conservation programs? How do our theoretical findings lead to new insights about the behavior of human and nonhuman animals? What is the value of our methodology for careful analysis of behavior? We run a real risk of being considered a marginal science, not worthy of more than cute videos and photos unless we become actively involved in educating all of our customers. (Session 29: Education Symposium; Tues. 4:50-5:10pm; Forum)
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P19 ROLES OF SYNTAX AND PHONOLOGY IN WHITE-CROWNED SPARROW SONG LEARNING
*Jill A. Soha & Peter A. Marler
Animal Communication Lab, University of California, Davis, CA 95616 (JASOHA@UCDAVIS.edu)
Selective learning of conspecific song in laboratory tape-tutoring experiments is thought to be guided by innate recognition of acoustic cues contained in song. Our goal is to describe the acoustic cues used in song learning by white-crowned sparrows (Zonotrichia leucophrys; WCSP). First, naive birds were tested for vocal response to playback of six song types: WCSP or heterospecific song, each with a whistle at the beginning, no whistle, or a whistle at the end. These young birds responded preferentially to songs containing WCSP phrases, regardless of the presence or placement of the whistle. Second, a group of birds was tutored with a set of 18 individually-presented song phrases, nine each from WCSP song and heterospecific song. These birds learned (assembled) songs of moderately complex syntax, which always began with a whistle. In addition, these birds did not preferentially learn WCSP phrases. These results suggest that note phonology is important early in the process of song learning, and song syntax emerges as a cue later on, perhaps during sensorimotor learning or repertoire attrition. (Founders Award poster; Sun. eve; Terrace)
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P89 LATENCY CHANGES IN THE EVOKED VOCAL RESPONSES OF THE FROG PLEURODEMA THAUL
*R. Solís, G. Acosta & M. Penna
Fac. de Cs. Vet.,U. de Chile,Casilla 2-Correo 15, Stgo, Chile (rsolis@abello.dic.uchile.cl)
Recent field studies have revealed an important plasticity in anuran vocal behavior. Male frogs have been shown to change the structure of their calls depending on the social context. The leptodactylid frog Pleurodema thaul produces a long advertisement call appropriate to explore temporal changes in vocalization. Evoked vocal responses of male frogs to prolonged exposure to a synthetic advertisement call (AC) and a variant consisting in an uninterrupted note (UN) were analyzed. Each frog was presented with the AC at 67 and 82 dB SPL (fast RMS), and with the UN at 67 dB. The response latency was significantly shorter for the AC at 67 dB relative to the AC at 82 dB and UN. The latency showed a significant trend to increase after the initial phase of exposure to AC at 67 and 82 dB. Our results show that latency of evoked vocal responses is susceptible of modification, in addition to the accommodation of signal structure and response thresholds reported for other anurans. FONDECYT grant 1970202 (General Posters; Sun. eve; Terrace)
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P90 EFFECTS OF DENSITY AND FEMALE MOVEMENTS ON MATERNAL AGGRESSION IN SOUTH AMERICAN FUR SEALS, ARCTOCEPHALUS AUSTRALIS
*Monica A. Sommer1, Daryl. J. Boness2, Stephen J. Insley2 and Patricia J. Majluf3
1Dept. of Zoology, Univ. of New Hampshire, Durham, NH 03824; 2Dept. Zool. Rsch, National Zool. Park, Smithsonian Inst., Washington, DC 20008; 3Wildlife Conservation Society, Paul de Beaudiez 520, Lima 27, Peru. (msommer12@aol. com)
Arctocephalus australis at Punta San Juan (PSJ), Peru have exhibited extremely high rates of maternal aggression and pup mortality, which previous studies have shown are related to high density and daily thermoregulatory movements. Density of fur seals at PSJ has declined ca. 10-fold, but whether thermoregulatory movements have declined is unclear. We studied rates of aggression at breeding areas with varying densities and rates of movement. Maternal aggression rates at PSJ were much lower in 1998 than in 1987/88 (0 - 2. 3 vs. 7. 3 threats/ 20 min). As expected, we found maternal aggression rates are correlated with female density. However, preliminary analyses suggest that maternal aggression and density may be less clearly related to thermoregulatory movements than previously thought; e. g., mothers in the area with the least aggression and lowest density had moderate (not low) amounts of movement. We may need to consider other interacting factors (e. g., stage of lactation and beach topography) to better understand this extreme variation in maternal aggression rates. (General Posters; Sun. eve; Terrace)
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86 EFFECTS OF PREDATION RISK AND INDIVIDUAL CONDITION ON PATTERNS OF SIZE ASSORTATIVE MATING IN A STREAM-DWELLING ISOPOD
*Timothy C. Sparkes & Andrew S. Sih
School of Biological Sciences and Center for Ecology, Evolution and Behavior, University of Kentucky, Lexington, KY 40506 (tsparkes@ceeb.uky.edu)
Population-level mating patterns will be a consequence of individual mating decisions (male choice, female choice, male-male competition, male-female conflict) that depend on both local ecological conditions (e. g., predation risk) and individual state (e. g., condition). The manner in which these factors interact will be complex and might often yield counter-intuitive patterns of mating. We examined the effects of predation risk and individual condition on patterns of size assortative mating (SAM) in the stream-dwelling isopod, Lirceus fontinalis. First, we documented the relationship between predation risk and SAM between populations that differ in levels of predation risk. We found that animals from high-risk populations exhibited stronger patterns of SAM than those from low-risk populations. We then used a laboratory experiment to attempt to partition the relative contribution of predation risk and condition to patterns of SAM. We will present results of this experiment and address the role of multiple behavioral mechanisms in explaining mating patterns in natural populations. (Session 16: Sexual selection III; Mon. 2:50-3:10pm; Olin)
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117 HOMOCIDE ON THE HOME FRONT: DOES TIMING EFFECT HOUSE WREN NEST DESTRUCTION BEHAVIOR?
Thomas McK. Sproat
Department of Biology, Ball State University, Muncie, IN 47036 (00TMSPROAT@BSUVC.BSU.edu)
Destruction of nests and their contents is an important ecological concern for many species of birds. While predation and interspecific competition account for most cases of nest destruction, in some cases nests are destroyed by conspecifics that are not associated with the nest. As part of a nest defense study, this project investigated the nest destruction behavior of house wrens Troglodytes aedon. Nest boxes were checked, on average, every three days and any nesting activity was noted. When nest destruction did occur, the most likely species of predator was identified. Conspecifics were the most common cause of reduced productivity and nest failure in house wrens. Most nest destruction activity occurred early in the egg and nestling stages. Nest destruction typically coincided with one of three stages of nesting activity in neighboring nest boxes. The timing of these nest destructions imply that house wrens time nest destruction behavior to maximize the intruder's fitness. These results support the mate intercept and move along theories for house wren nest destruction behavior. (Session 23: Predator/Prey III; Tues. 10:50-11:10am; Rooke)
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9 EFFECTS OF DENSITY ON HERMAPHRODITIC SEX ALLOCATION
*Colette M. St. Mary & Maria N. Sagastizabal
Department of Zoology, University of Florida, Gainesville, FL 32611-8525 (stmary@zoo.ufl.edu)
Population density affects sex allocation in a broad range of taxa. There are, however, a diversity of relationships between density and allocation, especially in hermaphrodites. We can resolve some of this variation, and achieve a more general understanding of sex allocation, through a closer examination of reproductive success and its relationship to allocation. Here we explore this issue with a dynamic optimization model of sex allocation. We then compare the predictions of the model to patterns of among-population variation in allocation. We find that the model does not predict substantial changes in allocation pattern unless density has several specific effects on male reproductive success, including effects on the distribution of male mating success and the number of mates per male. We argue that Lythrypnus dalli and Lythrypnus zebra differ in how density affects male mating patterns and thus, provide a useful comparison to the model predictions. Comparing sexual patterns of high- and low- density populations of each species, we find significant differences in their responses to density that are consistent with the predictions of the model. (Session 2: Sexual Selection I; Sun. 2:50pm; Rooke)
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53 A LEARNING-BASED MODEL OF TERRITORY ACQUISITION
*J. A. Stamps & V. V. Krishnan
Evolution & Ecology, Univ. Calif., Davis, CA 95616 (jastamps@ucdavis.edu)
We consider a few behavioral processes that can generate territorial spacing patterns in species living in patches of spatially heterogeneous habitat of uniform quality. The psychological literature indicates that some types of stimuli and experience increase the probability that an individual will return to a particular area, whereas other types of stimuli and experience (e. g. electric shock) reduce the probability of return. Simulations of settlement based on these rules, and which assume that every fight ends in a draw, generate many of the social and spatial patterns characteristic of territorial animals, including the formation of stable home ranges, increased home range exclusivity if individuals fight when they encounter one another, greater benefits of aggressive behavior under competitive conditions, and the prior residency advantage when residents and newcomers compete for the same space. Simulations in which individuals differ in competitive ability generate stable owner-floater spacing patterns, and show that individuals benefit from fighting unless they are much less competitive than their opponents. These results imply that crude versions of territoriality can occur in any taxon whose members are capable of spatial learning and punishing opponents. (Session 11: Resource Acquisition; Mon. 9:30-9:50am; Gallery)
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P91 COORDINATED PRECISION GRIPS AND MOVEMENTS IN TUFTED CAPUCHINS (CEBUS APELLA)
Valerie Staton
University of Georgia, Dept. of Psychology, Athens, GA 30602 (vws@compuserve.com)
Precision grips have been studied and classified in both apes (e. g. chimpanzees) and monkeys (e. g. tufted capuchins). It is often difficult to elicit precision grips in primate subjectsthe task must be such that the precision grip is preferable to the more often used power grips. In this study, subjects were required to insert a small shape through an equally small opening. With the exception of the circle, the shape often had to be rotated to be correctly aligned with the opening. While performing this task, the capuchins initially used precision grips, although they later switched to a less dexterous (and less efficient) method of completing the task. In addition to the precision grips used by the subjects, the coordinated movements and changes in the precision grips while aligning the shapes were captured on videotape. The adjustments will be compared to the classification of manipulative hand movements as demonstrated in humans, described by Elliott and Connolly (1984), to place capuchins' dexterity in comparative perspective. (General Posters; Sun. eve; Terrace)
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193 PREDATION ENHANCES COMPLEXITY IN EARLY EVOLUTION OF BIOELECTRIC SIGNALS
Philip K. Stoddard
Department of Biological Science, Florida International University, Miami, FL 33199 (stoddard@fiu.edu)
Sensory drive models predict that elaboration of courtship signals by sexual selection will be opposed by increasing conspicuousness to predators. In the gymnotiform electric fish, electric navigation signals show evidence of modification to avoid detection by predators prior to elaboration through sexual selection. Further, some adaptations favoring electric crypsis, the addition of phases to the electric organ discharge, appear to have provided the initial substrate for further elaboration of these signals through sexual selection. Three species lack adaptation for electric crypsis. The first (Gymnotus cylindricus) is geographically isolated from electroreceptive predators, the 2nd (electric eel, Electrophorus electricus) is itself an electroreceptive predator, and the 3rd (Brachyhypopomus sp.) is an electric Batesian mimic of the electric eel. Studies and models of sensory drive have postulated restrictive, simplifying forces of predation on signal evolution. These results show that early in signal evolution, sensory drive from predation can act to promote signal complexity as well. Supported by NIH/NIGMS-GM08205. (Session 39: Communication VII; Weds. 1:50-2:10pm; Rooke)
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37 PARENTAL CARE AND BROOD SIZE IN HOUSE FINCHES
*Andrew M. Stoehr, Kevin J. McGraw, Paul M. Nolan & Geoffrey Hill
Department of Zoology and Wildlife Science, Auburn University, AL 36849-5414 (stoeham@mail.auburn.edu)
Many studies quantify avian parental care by counting the number of feeding trips parents make to their nests, without considering the actual quantity of food brought with each trip. Furthermore, these studies often attempt to control for brood size by dividing the number of feeding trips by the number of nestlings. However, parents may respond to differences in brood size by adjusting feeding trip frequency, quantity of food brought in each trip, or both. We examined parental care in house finches. Using video cameras to film scales placed under nests, we quantified the numbers of feeding trips, feedings, and grams of food parents provided. Although parents increased feeding trips to larger broods, the relationship between brood size and food provided to each nestling was not linear once we considered the amount of food provided with each trip. The result was that nestlings in broods of intermediate size received more food than did those in larger or smaller broods. This study illustrates one problem with quantifying parental care when only the number of feeding trips is considered. (Session 8: Parental Care II; Sun. 4:10pm; Gallery)
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133 DISCRIMINATION OF NATURAL ACOUSTIC CATEGORIES BY BLACK-CAPPED CHICKADEES (POECILE ATRICAPILLUS)
*Chris Sturdy1, Leslie Phillmore1, Melissa Hughes2, Steve Nowicki2 & Ron Weisman1
1Department of Psychology, Queen's University, Kingston, ON K7L 3N6; 2Dept. of Zoology, Duke Univ., Durham, NC 27708 (sturdyc@psyc.queensu.ca)
Classifying oscine acoustic signals (i. e., song and call notes) into categories is a useful first step in reducing the complexity in a large sample of diverse vocalizations to simple accurate descriptions. This familiar technique has been applied to the analysis of the vocalizations of numerous songbird species. One well known example of such classification involved the calls of black-capped chickadees, specifically, the 'chick-a-dee' call. We trained wild-caught chickadees to simultaneously perform both within- and between-category operant discriminations of the A, B, C, and D notes of the 'chick-a-dee' call. Results showed that both males and females learned these call-note discriminations and that the inhibition of responding to non-food-rewarded categories of notes propogated strongly to novel call notes. Thus chickadees are able to perceive differences among individual call notes within call-note categories and group similar all notes together into open-ended call-note categories. Furthermore, memories for the outcomes of these call-note category discriminations are pervasive and long-lasting. (Session 26: Mechanisms II; Tues. 2:50-3:10pm; Gallery)
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132 ISOLATION'S EFFECTS ON AUDITORY PERCEPTION IN SONGBIRDS
Chris Sturdy, Leslie Phillmore, Jennifer J. Sartor & *Ronald G. Weisman
Department of Psychology, Queen's University, Kingston, ON, CANADA, K7L 3N6 (philly@psyc.queensu.ca)
It is well known that isolating male songbirds from conspecific song tutors dramatically affects the production of normal song. Recently it has been shown that relative to normally reared birds, male black-capped chickadees (Poecile atricapillus) reared in isolation are impaired in auditory discrimination tasks. Here we trained both normal-reared and isolate-reared male and female zebra finches in a perceptual assay of three auditory discriminations. We report that (1) more extreme levels of isolation resulted in greater perceptual deficits and (2) females show a small but significant deficit relative to males in these perceptual discriminations. Taken together our findings reveal that auditory perceptual development in male and female songbirds has a strong social component. Also, we hypothesized that male songbirds are superior auditory processors to females because they have a greater volume of neural tissue dedicated to auditory perception. (Session 26: Mechanisms II; Tues. 2:30-2:50pm; Gallery)
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35 DETERMINANTS OF INDIVIDUAL VARIATION IN REPRODUCTIVE SUCCESS
*Kimberly A. Sullivan1, James J. Roper1 & Wesley W. Weathers2
1Department of Biology, Utah State University, Logan UT 84322-5305; 2Department of Avian Sciences, University of California-Davis, Davis CA 95616-8532 (yejunco@cc.usu.edu)
Variation in clutch size has long been recognized as an important reproductive tactic in optimizing lifetime reproductive success. Potentially as important, but much less studied, is individual variation in the spacing of reproductive attempts within a breeding season. We used simulation models and demographic data from a population of Yellow-eyed Juncos to examine the potential role of variation in renesting intervals on reproductive success. Females with relatively short renesting intervals produced more nesting attempts during a breeding season and over all years observed in this study, produced more fledglings over the period of this study and had higher survival among their fledged young. Females with relatively low daily energy expenditure after accounting for body mass, air temperature and reproductive stage when measured renested faster and were more likely to breed in multiple years. Data on the demography and daily energy expenditure of Yellow-eyed Juncos suggest that individual females vary in their renesting intervals and propensity to overlap clutches, that this variation is a function of differential access to resources or the ability to use the available resources and that this variation can be an important component of lifetime reproductive success. (Session 8: Parental Care II; Sun. 3:30pm; Gallery)
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56 ROOST SITE SHIFTS AND MECHANISMS FOR ROOST TRADITIONALITY IN THE RUBYSPOT DAMSELFLY
*Paul V. Switzer1 & Gregory F. Grether2
1Department of Biological Sciences, Eastern Illinois University, Charleston, IL 61920; 2Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106 (cfpvs@eiu.edu)
Numerous animals aggregate into roosts and in many cases these roosting aggregations appear to be traditional, occurring at the same locations over time. We studied the roosting behavior of individual rubyspot damselflies, Hetaerina americana, to investigate roost site fidelity, spatial aspects of roost location choice, and traditionality. We found that both male and females tended to return close to their previous night s roost, but sex and territorial status did not influence their relative fidelity to sites. Males moved their roosting site closer to new territory locations over the course of a few days; however, they did not roost at locations that minimized the distance between their foraging sites and territory. During experiments, our model rubyspots recruited more rubyspots than controls, and we were able to establish lasting roost sites in novel locations. These results indicate that conspecific attraction and the roost fidelity are responsible for the establishment and traditionality of rubyspot night roosts. (Session 11: Resource Acquisition; Mon. 10:30-10:50am; Gallery)
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83 NONDIRECTIONAL FEMALE CHOICE IN A CHRYSOMELID BEETLE
Douglas W. Tallamy
Dept. of Entomology & Applied Ecology, University of Delaware, Newark, DE 19717-1303 (dtallamy@udel.edu)
The maintenance of heritable variation in male traits under directional selection from female mate preference has been a theoretical conundrum for nearly a century. This study uses the mating behaviour of the spotted cucumber beetle to evaluate variable female choice as one solution to this dilemma. Females discriminate among males on the basis of how rapidly males flutter their antennae over a female's head; males that antennate faster and more persistently are favored as mates. If certain conditions impede a female's ability to recognize quality males, genetic variation in antennation behaviour would be maintained rather than eliminated by female choice. This study used video assays to test the hypothesis that female age can influence the intensity of female choice. Results suggest that young virgins evaluated males 20 times longer than did older virgins. That is, older virgins completely forfeited the opportunity to evaluate male stamina and thus were more likely to accept the spermatophore of an inferior male. I conclude that female age at copulation is one variable that can maintain genetic variance in male traits under sexual selection. (Session 16: Sexual selection III; Mon. 1:50-2:10pm; Olin)
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P20 DIFFERENTIAL MATING SUCCESS IN A SCORPION: EVIDENCE OF MATE CHOICE?
*S. K. Tallarovic & Philip H. Brownell
Department of Zoology, Oregon State University, Corvallis, OR 97331 (tallaros@bcc.orst.edu)
Scorpions have long been neglected in mating systems research. As a relatively ancient arachnid they use an indirect method of sperm transfer (an external spermatophore) coupled with a stereotyped series of courtship behaviors. Experimental manipulations of reproductively active pairs of Hadrurus arizonensis have revealed differential mating success among both sexes. Certain females elicit more courtship behavior than others, and certain males are more successful in inseminating females. Some females mate with multiple males while others mate with only one. Mate rejection by both males and females appears to be common, but occurs at different stages of courtship for each sex. A positive correlation exists between body size and mating success, indicating that both sexes may preferentially mate with larger individuals. Reasons for mate choice in males may lie in the life history traits and evolutionary constraints common to scorpions. Females give birth to live young and provide limited maternal care, and larger females tend to have larger litters. Males produce a somewhat energetically expensive spermatophore and require several days to produce another. (Founders Award poster; Sun. eve; Terrace)
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P92 CONSPECIFIC AGGRESSION IN THE GIANT HAIRY DESERT SCORPION
*S. K. Tallarovic1, John M. Melville1, Leif K. Gundersen2 & Philip H. Brownell1
1Department of Zoology, Oregon State University, Corvallis, OR 97333; 2Department of Entomology, Oregon State University, Corvallis, OR 97333 (gundersl@ucs. orst.edu)
Aggressive behavior is generally seen as having two primary functions: a response to danger, and resource competition. These functions are usually distinct but overlap in cannibalistic species, such as many scorpions. Conspecifics may simultaneously represent competitors and either prey or predator. Hadrurus arizonensis is not highly cannibalistic, although interspecific predation contributes significantly to its diet. Laboratory studies of this species have revealed a set of complex and stereotyped behaviors unique to conspecific interaction that rarely result in injury or death. These behaviors can be separated into phases based on the level of physical interaction and usually terminate with a winner and loser. These behaviors occur among animals of different sizes and ages in intrasexual interactions year round and intersexual interactions outside of mating season. Laboratory experiments indicate that larger females are more likely to win encounters with other females, but size does not seem to play a critical role in male interactions or in intersexual interactions. Although the function of these behaviors remains unknown, we speculate they may be involved in species recognition and or may be used to defend a burrow. (General Posters; Sun. eve; Terrace)
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162 FUNCTIONAL ANALYSIS OF DROSOPHILA MELANOGASTER COURTSHIP SONG
Becky C. Talyn
Department of Biological Sciences, University of Maine, Orono, ME 04469-5751 (becky.talyn@umit.maine.edu)
Courtship in Drosophila melanogaster consists of a multimodal complex of behaviors, including a song produced when the male vibrates his wing. This song consists of two interspersed types of trains, pulse song and sine song. Since courtship can last up to an hour, the importance of the temporal organization of courtship song was investigated. Artificial songs were generated using a computer program, and differed from normal song in the amount of song per minute (song density) or in the proportions of pulse and sine song. Songs were played to groups of ten wingless males and ten females during a fifteen-minute observation period. Playback of artificial song induced mating at the same rate as playback of recorded songs regardless of song density. The proportions of pulse and sine song were also unimportant as long as some pulse song was present. I will compare the effects of modifying temporal organization to that of individual train characteristics, and speculate that the later is more important because courtship in nature is often brief. (Session 24: Evolution and Sexual selection II; Tues. 4:30-4:50pm; Olin)
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67 BEHAVIORAL AND EVOLUTIONARY MECHANISMS OF POLYANDRY IN HONEY BEES (APIS MELLIFERA)
David R. Tarpy
Entomology Department, Univeristy of California, Davis, Davis, CA 95616 (drtarpy@ucdavis.edu)
The high mating frequencies among certain social insects have gained increased attention within behavioral ecology but their adaptive significance is still in question. My objective was to investigate multiple mating behavior at both the individual and colony levels to determine why honey bee queens have evolved such high levels of polyandry. Two behavioral mechanisms, mating flight number and duration, were tested using an automated magnetic detection system. The results illustrate that queens do not regulate the number of times they mate, suggesting that extreme polyandry in honey bees is an epiphenomenon of variation in their mating ecology rather than providing an additional adaptive benefit over moderate mating frequencies. In a second experiment, a proposed mechanism of polyandry was tested for its effect on colony fitness. The findings suggest that low levels of polyandry may have evolved to reduce the genetic load caused by the single locus sex determination system in the Hymenoptera. The results of this project demonstrate some of the first empirical evidence for the evolution and maintenance of extreme polyandry in social insects. (Session 13: Allee Award session; Mon. 1:30pm; Forum)
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148 NAVIGATIONAL STRATEGIES OF ATTA CEPHALOTES (HYMENOPTERA: FORMICIDAE)
*Jim G. Thomas & Corey G. Washington
Department of Philosophy, University of Maryland, College Park, MD 20745 (jgthomas@wam.umd.edu)
Atta cephalotes are an ant species native to Costa Rica. They forage on plant leaves to make fungus gardens. Our research is aimed at determining the mechanisms relied upon when foraging. Through a series of experiments involving different maze set-ups in a lab, we have formulated a hierarchy of their navigational repertoire. We have determined that Atta cephalotes rely almost purely upon path integration when given a choice between that and either landmarks, canopy orientation, a single light source (whether the sun or a bright lamp), and in some instances, even their own trail pheromone. Our research is also aimed at determining how they process the information provided by each of the navigational strategies available to them. (Session 30: Foraging III; Tues. 3:50-4:10pm; Gallery)
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115 BEHAVIORAL REGULATION OF PHEROMONE EXPOSURE IN FEMALE SABLE ANTELOPE
*Katerina V. Thompson & Steven L. Monfort
College of Life Sciences, University of Maryland, College Park, MD 20742 (kt21@umail.umd.edu)
Urine sampling with subsequent flehmen has been implicated as a mechanism by which female sable antelope, Hippotragus niger, can introduce reproductive pheromones to the accessory olfactory system. In captive sable antelope at the National Zoological Park's Conservation and Research Center, frequencies of urine sampling and flehmen changed predictably over the course of the estrous cycle, reaching highest frequencies during the periovulatory period in both unmanipulated and experimentally synchronized herds. During the periovulatory period, females were also more likely to exhibit flehmen repeatedly in response to a single urination and were less likely to refrain from sampling urine voided by a nearby conspecific. Females generally did not discriminate among females of differing estrous status in sampling urine; rather, they sampled urine opportunistically from those in close proximity. These data suggest that a female s propensity to sample urine is influenced by ovarian hormones, resulting in cyclical changes in pheromone exposure consistent with the coupled oscillator model of estrous synchrony. (Session 22: Mechanisms I; Tues. 11:30-11:50am; Gallery)
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P93 THE APPLICATION OF MICROSATELLITE PRIMERS TO EVALUATE ALTERNATIVE MATING TACTICS IN PRAIRIE VOLES
*Michael G. Topping & Nancy G. Solomon
Dept. Zoology, Miami University, Oxford, OH 45056 (TOPPINM@MIAVX1.ACS.MUOHIO.edu)
Prairie voles (Microtus ochrogaster) have the potential to exhibit alternative mating strategies during the breeding season. Previous research has documented spatial variation consistent with a resident and a wandering mating strategy. In order to test alternative hypotheses concerning alternative reproductive behaviors, data on reproductive success of animals exhibiting these different patterns of behavior are required. We conducted an investigation to determine whether existing microsatellite primers would produce polymorphic amplification of DNA from prairie voles. Twenty-five primer pairs were screened using voles from 4 locations, to maximize the potential for genetic variability. Fourteen primer pairs failed to amplify prairie vole DNA, and 5 pairs produced monomorphic patterns. The remaining 6 pairs produced polymorphic banding, with at least 2 visible bands. These primers will be used in subsequent analysis to determine paternity of litters born in the field during 1998. Preliminary results indicate that there is sufficient genetic variation present to determine the paternity of litters using microsatellite analysis, and evaluate the potential for alternative mating strategies. (General Posters; Sun. eve; Terrace)
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P94 COSTS AND BENEFITS OF EARLY PAIRING IN THE HARLEQUIN DUCK
*R Torres, F. Cooke, G. Robertson & S. Boyd
Department of Biology, Simon Fraser University, 8888 University Drive, Burnaby BC, Canada V5A IS6 (rtorres@miranda.ecologia.unam.mx)
To investigate costs and benefits of early pairing in the Harlequin Duck, Histrionicus histrionicus, we compared time budgets and frequency of agonistic, courtship, and mate guarding interactions of paired and unpaired males and females. A total of 401 half-hour focal-animal sampling sessions were used in the analysis. Overall, the proportion of feeding time per session did not differ between paired and unpaired males and females. However, females spent more time feeding than males throughout the winter. While diving, paired males spent less time underwater than unpaired males, 22.89s vs. 23.87s, respectively. No difference in time underwater of paired and unpaired females was found. Paired males performed a greater frequency of interactions than unpaired males (2.05 vs. 0.59, respectively). Pairing status did not affect the overall frequency of interactions received by females, however, interactions received by paired females decreased from 1.68, in late October, to 0.42 by early May, while interactions received by unpaired females increased from 0.33 to 1.44, for the same period of time. Thus, early pairing may be costly for males: paired males spent less time underwater (presumably feeding) and more time in interactions. Benefits of early pairing for females are not clear. Paired females showed a decrease in the frequency of interactions received, however, pairing status did not affect time females spent feeding. (General Posters; Sun. eve; Terrace)
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95 DIALECT DISCRIMINATION IN THE HOUSE FINCH (CARPODACUS MEXICANUS): BEHAVIORAL RESPONSE TO LOCAL AND DISTANT SONG TYPES
Todd T. Tracy
Department of Biology, Colorado State University, Ft. Collins, CO 80523 (ttrac@lamar.colostate.edu)
Behavioral consequences of geographic song variation in birds are often unclear but may include assortative mating. I performed two experiments to assess the song preferences of female house finches and determine whether male dispersal is limited by female choice. In the first, birds were presented with local and nearby songs for a week and Midwestern songs for a week, and the elicited nesting behaviors (paper-shredding and string-gathering) were measured. In the second, I quantified the relative amounts of time birds spent near speakers playing local, nearby, and Midwestern songs. Preliminary results show that birds shredded significantly more paper to Midwestern songs than they did during the prestimulus (p<0.008, n=39). Birds shredded more to Midwestern songs than local songs and more to local songs than during the prestimulus, but these differences were not significant. The number of birds shredding paper during both sets of song stimuli was greater than the number of birds shredding during the prestimulus week (p<0.0025), but there was no significant difference between stimuli. Preliminary results indicate that, rather than preferring local songs, females may respond more strongly to unfamiliar songs, indicating that female choice may not limit male dispersal. (Session 18: Communication V; Mon. 4:30-4:50pm; Rooke)
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135 CURRENT OPTIMAL GROUPING MODELS CANNOT EXPLAIN VARIATION IN HOWLER MONKEY REPRODUCTIVE PERFORMANCE.)
Adrian Treves
1202 West Johnson Street, University of Wisconsin, Madison, WI 53706 (atreves@facstaff.wisc.edu)
Variation in fitness as a function of group size led researchers to formulate optimal grouping models. I analyzed census data from 26 populations of howler monkeys (Alouatta spp.) to determine if group size and/or composition correlated with estimated reproductive performance. Regression analyses were run separately for each population. Over a quarter of the sample showed strong correlations between group structure and estimated reproductive performance, yet only one group structure variable was a consistent predictor across the 26 populations. Groups with positive residuals of the number of adult and subadult males regressed on females, an index of sex ratio, contained more juveniles than expected from the population average. Hence, groups of disparate size with similar sex ratios had similar reproductive eprformances. These results are consistent with predictions about infanticide and female choice of male protectors, not predation or intragroup competition. Models of primate grouping should not focus solely on group size or on the opposed effects of predation and feeding competition. Conspecific threat must also be taken into account. (Session 27: Social behavior I; Tues. 1:50-2:10pm; Rooke)
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200 NESTING BEHAVIOR AND THE EVOLUTION OF COMPLEX PARENTAL CARE: A COMPARATIVE STUDY OF NICROPHORINES
*Stephen T. Trumbo & Derek S. Sikes
Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269 (trumbo@uconnvm.uconn.edu)
Among insects, the use of a nest is thought to be a key stepping-stone toward the evolution of complex parental and social behavior. The burying beetles (Nicrophorus spp.) are well known for their sophisticated nesting and parental behavior which includes burying a carcass in the soil, removal of hair or feathers from the carcass, deposition of antimicrobial secretions, and feeding and defense of young. Because the biology of closely related genera is poorly developed, we undertook studies of a non-nesting nicrophorine, Ptomascopus morio from Japan. Observational and manipulative experiments revealed unexpected behavioral complexity. Although preparation of the carcass is largely non-existent, P. morio parents regulated the size of the brood to match resource size and then maintained intimate contact with their brood over the entire 12 day developmental period. The importance of nesting for the evolution of parental care among insects will be discussed. (Session 40: Parental Care III; Weds. 2:30-2:50pm; Olin)
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94 MULTI-MODAL COMMUNICATION AND MATE RECOGNITION IN WOLF SPIDERS
*George W. Uetz, Melissa A. Orr & J. Andrew Roberts
Dept. of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221-0006 (uetzgw@email.uc.edu)
Wolf spiders (Lycosidae) use multi-modal communication (visual and vibratory cues) as well as complex multiple-component visual signals in courtship. Here, we examine the role(s) of various aspects of male courtship in mate recognition and preference among closely-related species of the genus Schizocosa. Results of cue isolation experiments suggest that courtship modes have diverged in these species. In some cases, a single component is necessary and sufficient to elicit female receptivity, while in others, multiple components are equivalent in ability to elicit responses. Video/audio playback cue-conflict experiments (conspecific/heterospecific components together) show that females respond to mixed information in the same manner as they do heterospecific males. Video playback experiments manipulating multiple components of visual displays (decorative leg tufts and display rate) in male S. ocreata show female receptivity varies with both traits independently, as well as together. As tufts and behavior may vary with condition in live males, visual signaling may serve an indicator trait function in female mate choice. The role of various signaling modes, and the evolution of multiple modes is discussed. (Session 18: Communication V; Mon. 4:10-4:30pm; Rooke)
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159 PLASTICITY IN MATE SEARCHING TACTICS REDUCES SEARCH COSTS IN SATIN BOWERBIRDS
*J. A. C. Uy, G. L. Patricelli & Gerald Borgia
Department of Biology, University of Maryland, College Park, MD 20742 (au7@umail.umd.edu)
Understanding sexual selection requires knowledge of how females search for mates. Current models of mate searching consider that females only use a single tactic. Here we consider individuals showing plasticity in mate searching behavior and how this can reduce search costs. Using past experience in searching for mates and remating with males of known high-quality in subsequent years can be effective in reducing search costs. We followed 63 female satin bowerbirds Ptilonorhynchus violaceus during mate searching and found that females who chose high-quality mates typically remated with the same male in the following year, visiting fewer males than females who switched mates. Females who mated with lower quality males searched and then selected higher quality males in the subsequent year. These observations suggest that females use long-term memory either to reduce search costs by returning to high-quality males for matings or to make decisions to switch mates and find higher-quality males. This study of a long-lived animal suggests that mate searching involves information accumulated over multiple years; a factor that is not often considered in studies of sexual selection. (Session 32: Evolution and SS II; Tues. 3:30-3:50pm; Olin)
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157 PUBLIC INFORMATION AND THE BENEFITS OF SOCIALITY
Thomas J. Valone
Department of Biology, California State University, Northridge, CA 91330-8303 (Thomas.Valone@csun.edu)
Public information is information an individual acquires by noting the activities of other individuals. The use of public information can speed resource estimation and provide more accurate estimates of resource quality. Public information was originally conceived in a foraging patch assessment context but is applicable to many aspects of behavior. I review public information use in a variety of contexts: breeding habitat assessment, mate choice, food calls, and opponent assessment. Public information use may be widespread and thus may help to explain the evolution and maintenance of many social behaviors. (Session 31: Social behavior II; Tues. 4:50-5:10pm; Rooke)
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190 MECHANISMS OF CHEMO-ORIENTATION OF CRAYFISH IN TURBULENT WATER CURRENTS
*Michael van der Wall & Thomas Breithaupt
Department of Biology, University of Konstanz, 78457 Konstanz, Germany (michael.van.der.wall@uni-konstanz.de)
Previous studies on the orientation of marine crustaceans led to the conclusion that chemical and mechanical stimuli can play important roles in initiation and control of orientation behavior in turbulent odor plumes. We wanted to know whether the animals use the spatial and temporal fine structure of such plumes to extract directional information for finding an odor source, or whether the animals use the local flow direction for orientation toward the odor source. Orientation behavior of two crayfish species (Austropotamobius torrentium and Procambarus clarkii) was examined in a flume of 1m width and 5m length. A large obstacle positioned downstream of the odor source generated big eddies and turbulences. During their search crayfish moved through this turbulent wake and passed the obstacle to approach the odor source. Hydrodynamical and chemical stimuli in front of the animals were recorded simultaneously using plastic particles and dye as markers for visualization. Crayfish to a large part of their search used rheotactic orientation. Changes in walking direction corresponded to changes in flow direction. Reactions to changes in the flow direction followed with a latency of about 1 second. Supported by Deutsche Forschungsgemeinschaft (Br 1321/3-1,2). (Session 38: Mechanisms IV; Weds. 2:30-2:50pm; Gallery)
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114 DIFFERENTIAL EFFECTS OF SEXUAL HORMONES ON STRUCTURE AND BEHAVIOR IN A MORMYRID FISH, GNATHONEMUS PETERSI
*A. Voustianiouk1 & P. Moller2
1Department of Psychology, Hunter College; 2GSUC of The City University of New York, 695 Park Avenue, New York, NY 10021 (andreiv@worldnet.att.net)
Mormyrid fish exhibit sexual dimorphisms in the structure of the anal fin rays, indentation of the posterior ventral body wall, and electric organ discharge (EOD). These characteristics are hormone-sensitive and can be induced in juveniles and adult females through administration of various natural and synthetic androgens. The mechanism of hormonal action is poorly understood. To identify specific functional androgen targets, 20 subadult G. petersii were gonadectomized and implanted with silastic capsules containing either testosterone (T), dihydrotestosterone (DHT), estradiol (E), or nothing (controls). To assess structural changes, fish were radiographed every two weeks. EODs were recorded twice a week. Within four weeks, androgens induced significant structural and behavioral masculinization. EOD was significantly more affected by T than DHT, but morphology was significantly more affected by DHT. E had no effects. Structural characteristics and EOD were significantly correlated. Thus, structural and behavioral masculinization is strictly and selectively androgen-specific, and not aromatization-dependent. Implications of these results on development and reproduction will be discussed. (Session 22: Mechanisms I; Tues. 11:10-11:30am; Gallery)
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169 DEVELOPMENT OF DIFFERENTIAL FLEHMEN RESPONSE IN FOALS OF EQUUS CABALLUS
*J. W. Weeks1, S. L. Crowell-Davis2, G. Heusner3 & A. Caudle4
1Department of Psychology, Franklin College of Arts and Sciences, University of Georgia, Athens, GA 30602; 2Department of Anatomy and Radiology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602; 3Extension Animal Science, Department of Agriculture, University of Georgia, Athens, GA 30602; 4Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (weberw@arches.uga.edu)
The flehmen response is commonly seen in most ungulates as well as in several other species (i.e. felids). The behavior is most often thought of in conjunction with the sexual behavioral repertoire of males. One reigning hypothesis suggests that this behavior allows the male animal to determine the estrus state of a female through the chemosensory functions of the vomeronasal organ (Estes, 1972). However, this behavior is also exhibited by females and young of both sexes. Horse foals most frequently show the flehmen response during their first month of life with colts showing the behavior more frequently than fillies (Crowell-Davis, 1985). This study was designed to test the flehmen response of male and female foals throughout their pre-pubertal period. Foals were separately presented estrus and non-estrus mare urine weekly during the first month of life and then monthly until they reached approximately 7 months of age. Each five minute presentation of urine was videotaped. Tapes were then analyzed for the following behaviors: sniffs, latency to flehmen and the frequency and duration of flehmen. Differences in the expression of the flehmen response between colts, fillies and early pre-pubertal castrates were assessed. Results will be discussed. (Session 33: Development I; Weds. 11:30-11:50am; Forum)
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P21 INDIVIDUAL AND CONTEXTUAL VARIATION IN THE SQUEAKING VOCALIZATION OF WOLVES (CANIS LUPUS)
*Jacqueline N. Weir & Rita E. Anderson
Biopsychology Programme, Memorial University of Newfoundland, St. John's, NF, A1B 3X9, Canada (jweir@play.psych.mun.ca)
Little is known about squeaking, the most frequent close-range vocalization of wolves. The purposes of this study were 1) to determine diurnal patterns, frequency of occurrence, and range of social contexts of squeaking and 2) to assess the individual and contextual variation in the squeaking vocalization. Squeaking events were identified from the 1995-1997 videotapes of the social behavior of captive wolves at the Canadian Center for Wolf Research, Shubenacadie, Nova Scotia; additionally data were obtained from seven 24-hr watches. Wolves squeaked most frequently during