University of Sourthern Mississippi (sarah.mabey@usm.edu)

I hypothesize that one benefit for Eastern Kingbirds joining conspecific flocks is acquiring information about the safety and profitability of exploiting novel resources encountered during intercontinental migration. If true, the presence of experienced conspecifics should release naive individuals from their neophobic response to novel foraging opportunities. I tested 16 naive, adult kingbirds in a sequence of four experimental trials in which they were paired with a conspecific that was either naive or experienced and the feeding opportunity was either familiar or novel. A fifth trial retested the "naive-naive novel" situation to examine the possibility of general habituation to novelty. Data are consistent with the hypothesis, indicating that 1) naive Eastern Kingbirds express neophobia in response to novel feeding opportunities; 2) neophobic responses are significantly alleviated by the presence of an experienced bird but not another naive bird; and 3) kingbirds exhibit a limited ability to habituate to a general class of novel feeding opportunities. The social mitigation of neophobia in naive birds by experienced birds suggests that joining conspecific flocks may be an important strategy for coping with the incumbent novelty of migration. (Social Behavior 1; Mon. 3:00pm-3:15pm; NMM2)

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Universidade de Brasília & Washington State University (rhmacedo@unb.br)

Communally breeding guira cuckoos produce clutches correlated with group size and exhibit egg ejection behavior. Egg-laying order, and group size/composition may affect female success. We examined how egg-laying order, egg ejection probability, and group size affected egg nutrient investment. Egg ejection probability decreases as laying progresses, and is lower in larger clutches. Egg volume is associated with laying sequence, increasing as egg ejection probability drops. Overall, egg volume is lower in smaller clutches, where there is the highest ejection probability. There is no association between yolk volume and laying order or clutch size. However, tossed eggs contain smaller yolks than those retained. Our results suggest an advantage for low-ranking females in belonging to larger groups, where power struggles" for dominant placement during egg-laying may be inconsequential. Furthermore, females may have the capacity to increase or decrease investment in egg or yolk volume, according to the survival chances of their eggs. (Parental Care 1; Sun. 11:15 AM - 11:30 AM; NMM1)

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University of Georgia (paulmack@arches.uga.edu)

Some evidence currently exists concerning the genotypic variability for sperm competitive ability in natural populations of Drosophila melanogaster. However, no prior study has attempted to determine strictly genetic variation in these traits or genetic correlation between these and related male reproductive fitness traits. We estimated variance components for sperm competitive ability, specifically P2, male fertility, and probability of remating. Ultimately, we used a maximum likelihood approach to estimate variance components for both P2 and male fertility. Overall variation was similar to that observed in prior studies where homozygous lines of D. melanogaster extracted from both wild and laboratory populations. We found significant differences among lines for both P2 and male fertility with or without including within-line crosses in the analysis. These results extend our view of the standing genetic variation in various measures of sperm competition and the apparent lack of at least genotypic correlation among them found by previous investigators. Our results are also consistent with the previous finding that male by female genotype interactions are important (Clark et al 1999). I will discuss how our results along with previous work help us further understand the mechanisms that maintain polymorphism for sperm competitive ability in natural populations. (Sexual Selection; Sun. 5:00pm-5:15pm; NMM2)

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St. Lawrence University (pcain@stlawu.edu)

Landmarks aid navigation by providing information about the surrounding environment, such as distance and direction to a specific goal. There is evidence that fish use landmark cues to form an internal representation of their environment. This study examined: 1)whether landmarks helped G. petersii locate an aperture in a clear plastic wall, 2) whether water depth or landmark cues are the primary cue used by the fish in a familiar environment, and 3) whether landmark size affected navigation trajectory. We hypothesized that weakly electric fish: 1) will find the aperture faster with a landmark present than without, 2) will rely on water depth cues over landmark cues, and 3) that fish will modify their trajectory if the landmark size is changed. Our data indicate that G. petersii found the aperture faster with landmarks and attended to water depth cues over landmark cues, but did not consistently modify their path if the landmark size changed. (General Poster Session; Tues. evening; Archer Hall Gym)

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Brookfield Zoo, Northwestern University (s-margulis@nwu.edu)

Animal behavior, if it is taught at all at the high school level, is relegated to a few days, late in the school year. Here, I describe a 4-week animal behavior curriculum, "Behavior Matters," that serves as an introduction to the scientific method, and introduces students to animal behavior and its relevance to solving real-world conservation problems. We capitalize on the natural fascination children have for animals and leverage this to engage students. Developed collaboratively by the Center for Learning Technologies in Urban Schools and Brookfield Zoo, the unit includes a series of lead-in activities, a videotape, and a software program. The unit concludes with a field trip to Brookfield Zoo, where students collect and interpret real data. Here, I describe results of the initial use of the curriculum in middle and high schools during the 1999-2000 school year, and the collaborative process that enabled us to develop a curriculum that is teacher-friendly, scientifically accurate, and fun for students. (Conservation; Weds. 10:30 AM - 10:45 AM; Sale)

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Emory University (lmarino@emory.edu)

Primates and cetaceans are distinguished by their possession of the highest levels of encephalization (i.e., the largest brains when body size is accounted for) in the animal kingdom. The brains of both groups show evidence of a high degree of cortical elaboration and organizational change from their purported ancestors. Yet the brains of primates and cetaceans also display very different trends and characteristics which have resulted from the two groups having highly divergent evolutionary paths for tens of millions of years. In this presentation I will highlight some of the major anatomical differences and similarities among cetacean and primate brains, discuss how these differences and similarities are possibly related to functional differences and similarities and, speculate on what comparisons of primate and cetacean brains can tell us about our present theories of mammalian brain evolution. (Comparing Primates & Cetaceans Symposium; Weds. 10:45 AM - 11:30 AM; Sale)

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University of Missouri - Columbia (vtm1da@mizzou.edu)

Male spring peepers use "aggressive" vocalizations that are distinct from advertisement calls during agonistic interactions over calling sites. In a field playback experiment, we broadcast synthetic advertisement calls at an amplitude 4 dB above a male’s previously determined threshold for giving aggressive calls. While all males initially responded aggressively to the stimulus, the number of aggressive calls declined rapidly as the playback progressed, and most males gave exclusively advertisement calls one minute into the playback. Additionally, we observed a significant but temporary increase in the threshold for switching to aggressive calls when it was remeasured immediately post-playback. In separate two-speaker phonotaxis experiments, 75 percent of female spring peepers preferred the speaker broadcasting only advertisement calls to an alternative playing only aggressive calls or one that alternated advertisement and aggressive calls. These results suggest that female preferences for functionally different call types may be more permissive in spring peepers than in other frogs. We discuss female call type selectivity as one possible influence on plasticity of male aggressive calling in spring peepers. (General Poster Session; Tues. evening; Archer Hall Gym)

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Butler University (tmartens@butler.edu)

Our long-term project concerns the impact of two calves on the social structure and behavioral repertoire of a captive herd of African elephants (Loxodonta africana). Five adult female African elephants were observed at the Indianapolis Zoo. Two were pregnant. We present preliminary data on the herd's social structure and on the elephants' behaviors before the births of the calves. A focal-sampling procedure was used, with each animal being observed in morning and afternoon sessions. A continuous recording technique was used, distinguishing between ongoing activities and discrete/brief behavioral "events". The captive herd engaged in a wide variety of behaviors, resembling those reported for wild herds. The pregnant elephants were near the bottom of the dominance hierarchy, as measured by the dyadic interactions among the elephants. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Wisconsin & N. Carolina State University (camarler@facstaff.wisc.edu)

Arginine vasotocin (AVT) is a neuropeptide hormone that influences acoustic communication in a number of taxa. In contrast to other studies suggesting that AVT only influences probability of calling in anurans, we demonstrate that AVT can have more complex effects on calling behavior. In the gray treefrog, Hyla versicolor, peripheral injections of AVT increase an intruder male's ability to acquire a calling site under field conditions, without using aggressive calls or physical aggression. This ability to acquire calling sites may be influenced by advertisement call changes induced by AVT. Males injected with AVT give longer calls with more pulses. Other researchers have demonstrated that these call traits are attractive to females. Preliminary data indicate that intracerebroventricular injections of AVT given under semi-natural field conditions induce the same behavioral changes as peripheral injections. Overall, these studies suggest AVT significantly influences acoustic communication by acting directly on the central nervous system to induce behavioral changes not only in the injected individuals, but also in individuals in their social environment. (Mechanisms of Behavior; Mon. 11:15 AM - 11:30 AM; NMM1)

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University of Lethbridge (mather@uleth.ca)

Swimming in daytime at midwater over coral reefs and rubble near shore, squid frequently encounter potentially threatening fish. To understand how squid might gage their reaction, 945 approaches of individuals of 30 species were recorded with size, speed and distance of fish and squid reaction by movement and colour change. Squid responded very differently to three fish which commonly approached. Parrotfish (Scarus sp.) were often allowed to approach within 1 m, and squid responses, while seldom the extreme of paling and fast escape, depended on their speed and size. Yellowtail snapper (Ocyurus chrysurus) were seldom able to approach closer than 2 m and their speed of approach predicted squid responses. Bar Jack (Caranx ruber) were reacted to at a wide ranges of distance, with response more dependent on distance. Squid approached only one fish, spotted moray eels (Archer Hall Gymnothorax moringa) foraging in the coral rubble. Small squid were noticeably more 'jumpy' than adults but depended on the same approach characteristics. The role of visual and mechanoreceptive cues about the fish as well as learning in guiding these responses will be discussed. (Anti-predator Behavior; Tues. 5:45pm-6:00pm; NMM2)

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University of Louisiana (lmm4706@louisiana.edu)

Social monogamy may have evolved in snapping shrimp as a result of advantages to males through extended mate guarding of females and/or advantages to one or both sexes through cooperation (e.g., burrow maintenance, defense, foraging). The mate guarding hypothesis predicts 1) males should alter guarding durations in response to differences in overall population density, which affects encounter rate with females, and 2) males should prefer to pair with females that are nearly sexually receptive over females that are not. Data from natural populations of Alpheus angulatus revealed no significant difference in pairing in relation to density, and data from laboratory experiments reveal no significant male preference for females closer to sexual receptivity. The cooperation hypothesis predicts that either or both sexes experience a reduction in the risk of eviction as a result of "cooperative" territorial defense from non-pair conspecifics. Laboratory experiments revealed that 1) females in pairs did enjoy a significantly reduced risk of eviction, but 2) males in pairs did not, and males were significantly more likely to abandon the burrow than females. Furthermore, males were more likely to abandon the burrow if their mates were far from sexual receptivity than if their mates were close to sexual receptivity. (W.C. Allee Competition; Mon. 2:00pm-2:15pm; Sale)

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Ohio State University (rmauck@osu.edu)

Animals living in groups are thought to gain fitness through decreased predation risk, while often paying a cost in terms of increased competition in foraging. Thus, the balance struck between predator avoidance and foraging should be affected by group membership. For animals that avoid predation by hiding, such as the northern rock barnacle (Semibalanus balanoides), that balance is particularly important since predator avoidance excludes foraging altogether. We tested the hypothesis that barnacles living in groups should spend less time hiding when faced with a perceived threat than should solitary barnacles. We presented group-living and solitary barnacles with a simulated threat and measured hiding time with the prediction that barnacles in groups would return to foraging more quickly than would solitary barnacles. We then manipulated barnacle group size using an A-B-A design in which barnacles were tested in one of two sequences, solitary-group-solitary, or group-solitary-group. We found that group membership had a significant effect on the barnacle foraging behavior in that individuals emerged from hiding sooner when tested in a group than when tested alone. We conclude that group membership strongly affects foraging decisions by this simple, refuge-using animal. (Anti-predator Behavior; Tues. 3:00pm-3:15pm; NMM2)

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Cornell University (djm36@cornell.edu)

Habituation techniques are often used to assess discrimination of call types, individual voices, and individual odors. Decreased attention to a repeatedly presented (familiar) stimulus indicates habituation; subsequent increased attention to a novel stimulus indicates discrimination. Simultaneous presentation of both stimuli for discrimination introduces a spatial component because they cannot be in the same place. In this study twelve test conditions elucidated the effect spatial arrangement of social odors had on individual-odor discrimination. Female hamsters discriminated flank odor of two males when novel scent was on the half of the glass plate that was clean on the last habituation trial but not when it was on the half that had contained familiar scent. Odor discrimination not confounded with spatial arrangement occurred when familiar odor occupied the entire glass plate during habituation and novel and familiar odors were on opposite halves during discrimination. Thus, odor location and novelty are salient to solitary, presumably territorial, hamsters. Separating olfactory from spatial discrimination is essential for investigating individual-odor recognition and its neural mechanisms. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Kentucky (tmmcca0@pop.uky.edu)

Chemical signals are an important component influencing predator-prey interactions. Studies have shown that injury-released chemicals resulting from predation events warn prey of potential risk. Early detection of risk can decrease prey mortality. However, cues indicating predation risk might increase prey mortality rates if predators also respond to these chemicals in the environment. Therefore, there exists a race of response, with the outcome dependent on the strategies and relative mobility of both the predators and prey. We examined responses of aquatic snails (prey) and two species of crayfish (predators) when exposed to injured-snail cues. Snails (Physa gyrina) exhibited significantly greater refuge use (i.e. moving to the waterline, floating or crawl-out) when exposed to injured-snail cue. Crayfish responses showed species-level differences: Orconectes rusticus exhibited low activity levels in trials without cue introduction and significantly higher activity levels when exposed to injured-snail cue; Procambarus clarkii exhibited high activity levels across treatments. Crayfish of both species consumed snails faster when exposed to injured-snail cue, but differences between treatments were not significant, perhaps as a result of the snails’ avoidance responses. (Anti-predator Behavior; Tues. 3:15pm-3:30pm; NMM2)

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University of Georgia, Yerkes Regional Primate Center & University of Chicago (kaim@arches.uga.edu)

This study examined the development of social behaviors during the first three months of life in maternally maltreated and non-maltreated rhesus macaques Macaca mulatta. Based on attachment theory and previous primate studies, it was predicted that maltreated infants would be less likely to leave their mothers, explore the social environment, and play with their peers than non-maltreated infants. Four abusive and five non-abusive female rhesus monkeys were observed with their infants during the first 12 weeks of the infant's life in a captive group at the Yerkes Field Station. Results show that maltreated infants engaged in play with others at a later age, and less frequently than did the controls. Maltreated infants were rejected more by their mothers and experienced an increase in rejection over the twelve weeks compared to the controls. Maltreated infants were also more likely to be kidnapped and harassed by adult females during the first ten weeks. The findings of this study suggest that infant social development in rhesus macaques is affected by early maltreatment and are consistent with the results of previous studies of infant maltreatment in humans and other primates. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of California - Davis (bmccowan@vmtrc.ucdavis.edu)

Innovative approaches for analyzing vocal communication are needed to investigate the behavioral ecology underlying the composition and structure of mammalian vocal communication systems. This approach will require a quantitative and comparative analysis of animal vocalizations from different populations and species. While extensive research has been conducted on many avian species, especially songbirds, few studies to date have quantitatively examined vocal and repertoire structure in relationship to social or ecological strategies in populations of captive or free-ranging mammalian species. This lack of information on the structure and organization of vocal repertoires has hindered our understanding of the behavioral ecology and evolution of mammalian vocal communication. Mathematical models are needed that link ecological and evolutionary principles with the processes of communication systems across the diversity of mammalian species. We will present and discuss quantitative and comparative measures of animal communication that can provide novel insights into the ecological and social processes that shape the structure, organization, and function of vocal repertoires. We will discuss how predictions on the structure and organization of animal communication systems can be made from information theoretic measures in light of behavioral ecology and evolutionary theory. Using bottlenose dolphins and squirrel monkeys as examples, we consider each level of communication, from the acoustic structure of a single call type to the complexity of call sequences, for a comprehensive approach toward animal vocal development and communication and their relationship to the processes underlying and evolution of human language systems. (Comparing Primates & Cetaceans Symposium; Weds. 1:30pm-2:00pm; Sale)

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University of Tennessee (lemur73@bellsouth.net)

The most common route to speciation is thought to involve the physical isolation of two populations, which allows genetic differences to accumulate. Recent mathematical models suggest that in small populations, sexual selection can be a potent force driving speciation. We report studies of a potential model system for such isolation, two lines of D. melanogaster that were selected in the mid 1950's, one for DDT resistance and the other as a susceptible control. The resistant line experienced repeated bottlenecks during its initiation. In the ensuing approximately 1500 generations, these lines have not been outbred. A decade after the original selection, the lines were found to differ in fertility, fecundity, and longevity. We have remeasured these life history traits and have also tested for behavioral isolation in all combinations between the two lines and Oregon-R, a wild-type laboratory stock. Life history characters have changed since 1966 but in complex ways not predicted by the earlier authors. Furthermore, behavioral isolation may be developing between Oregon-R and at least one of the lines. (John Paul Scott's Founders Poster Session; Tues. evening; Archer Hall Gym)

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Valdosta State University (cmcdonou@valdosta.edu)

We identified various categories of anatomical damage occurring in a wild population of nine-banded armadillos in northern Florida and recorded the frequency of occurrence and extent of damage in different groups of individuals. Damage accumulated with age and adults exhibited more types of damage than did juveniles, but the extent of any particular form of damage did not differ between age groups or between males and females of the same age. We used microsatellite DNA analyses to identify putative parents of 69 litters of armadillos. Parents did not differ from non-parents in the occurrence or extent of phenotypic damage. Lactating females exhibited more damage than did non-lactating females but this may have been an age effect, because lactating females were also older than non-lactating females. In an earlier study we found few correlates with fitness in this population. The present study, coupled with these earlier findings, suggest reproductive success in this population was relatively random over the years studied. (General Poster Session; Tues. evening; Archer Hall Gym)

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Cornell University (kjm22@cornell.edu)

The striking diversity of sexual dimorphisms in nature begs the question: why are there so many signal types? One possibility is that ornamental traits convey different sets of information about the quality of the sender to the receiver. The colorful, pigmented feathers of male birds seem to meet the predictions of this hypothesis. Evidence suggests that carotenoid pigmentation reflects the nutritional condition of males during molt, whereas in many instances melanin ornamentation is a reliable indicator of social status. However, as of yet there have been few experimental tests to determine the comprehensive costs of either ornament type. Thus, it is unclear whether melanin pigmentation may also represent the health and condition of males and whether carotenoid ornaments honestly signal fighting ability. I found that endoparasitic infection by intestinal coccidians (Isospora sp.) significantly depressed the expression of carotenoid pigmentation in captive male American goldfinches (Carduelis tristis), but did not influence melanin-based cap coloration. Moreover, experimental manipulations of the carotenoid-based plumage of male house finches (Carpodacus mexicanus) demonstrated that this ornament is an unreliable indicator of social status in the winter. These studies provide robust support for the notion that carotenoid and melanin ornaments have fundamentally different signal content in birds. (Communication 1; Weds. 10:45 AM - 11:00 AM; NMM1)

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University of Memphis (smech@memphis.edu)

We tested the hypothesis that scent marking and aggressive interactions measure the same form of dominance. To test this hypothesis, we performed three experiments using the prairie vole (Microtus ochrogaster). First, we paired 64 males and performed scent-marking and agonistic trials on each pair and found no correlation between the two measures of dominance. In the second experiment, we paired 42 males and performed scent-marking tests immediately before and after an agonistic test. The results from this experiment showed no correlation between the agonistic and either scent-marking test, but the two scent-marking tests did correlate. This suggests that direct short-term interaction does not change scent-marking patterns. The third experiment used two groups of six males each. We performed scent-marking and agonistic interaction tests before and after placing the males into enclosures for extended periods of time. Overall, the only significant correlation between measures was the agonistic interactions before and after placement in the enclosures. Together, these data suggest that scent-marking and agonistic interactions do not measure dominance the same way. We conclude that comparison of results between different studies that use different measures of dominance requires extreme caution. (Dominance & Resource Defense; Tues. 10:15 AM - 10:30 AM; NMM2)

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Hamline University (medeiros_matthew@hotmail.com)

Damselflies, like many other organisms, may choose which direction they will face when perching. This positional orientation may aid in thermoregulation, since by altering orientation, an individual alters the amount of body surface exposed to the sun, and therefore, their internal temperature. Small insects may also attempt to face into the wind to perch in the most aerodynamically efficient way possible. In insects, positional orientation has been widely reported and assumed to be for thermoregulation. However, such orientation has rarely been quantified. Thus, whether insects really orient at all in the field remains virtually unconfirmed. I quantified the orientation of I. ramburii in the field at various times of the day. I. ramburii showed strong positional orientation, facing into the wind and perpendicular to the sun’s incoming rays during much of the day. These results are consistent with both the thermoregulation and aerodynamic efficiency hypothesis. (Habitat Choice; Mon. 4:45pm-5:00pm; Sale)

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University of California - Davis (clmeehan@ucdavis.edu)

Due to their popularity as pets and in zoo collections, parrots are one of the most common groups of non-domesticated animals kept in captivity. Captive parrots retain the behavioral capacities of their wild counterparts, despite vast differences between wild and captive environments. This difference may profoundly affect the behavioral development and welfare of captive parrots. Here, sixteen Orange-wing Amazon parrots were assigned to either a control or an enriched cage at 4 months of age. The enriched cages contained foraging devices and stimuli designed to increase the physical complexity of the cage. Regular observations were made for one year to record interactions with these enrichments. Additionally, behavioral differences between the two groups were assessed every four months. The birds from the enriched group showed less aggression toward a strange handler (Repeated measures ANOVA: F1,14=11.67; p=0.004) as well as decreased latency to interact with a novel object (F1,14=8.00; p=0.014). However, the control birds spent longer interacting with the same novel object than did the enriched group (F1,14=21.63; p<0.001). The development of abnormal behaviors including locomotor and oral stereotypies and feather plucking was also recorded. The implications of these results for the welfare of captive parrots will be discussed. This work is funded by the Kenneth A. Scott Charitable Trust. (Applied Animal Behavior; Tues. 11:45 AM - 12:00pm; Sale)

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Ohio University (jm703496@oak.cats.ohiou.edu)

Males of many species of swordtail fish in the genus Xiphophorus (Cyprinodontiformes: Poeciliidae) have vertical body bars on their flanks that are important in species recognition, male-male competition, and female mate choice. Species of this genus are often found in sympatry in the Rio Panuco basin and swordtails readily hybridize in captivity, yet only two species of swordtails are known to hybridize in nature: X. birchmanni and X. malinche in the Rio Calnali. To determine what morphological differences are present between these populations, males were collected from this hybrid zone and compared with X. birchmanni and X. malinche males from allopatric populations in a multivariate analysis. There were several traits that served as good discriminators between allopatric X. birchmanni and hybrids, however X. malinche males were highly variable. The possible implications of these differences on female mating preferences in the hybrid population will be discussed, as well as possible correlates among other species in this genus. (John Paul Scott's Founders Poster Session; Tues. evening; Archer Hall Gym)

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University of California, Riverside (melamed@keyway.net)

Food distribution can affect space use of animals and consequently, might affect the frequency of aggressive interactions with neighbors. In this study the frequency and duration of agonistic encounters between males were compared among two control unmanipulated populations and two population replicates of each of two food distribution treatments (even and clumped supplemented food distributions). Analysis of 223 15-minute focal observations support earlier findings using 289 2-hour scan observations, that clumping of food resulted in an increase in both the frequency and the time males spent on agonistic interactions. In even and clumped food supplemented populations, interactions between an aggressor and a subordinate took place significantly closer to the aggressor’s home burrow (20.1 and 24.4 m, respectively) relative to the subordinate’s home burrow (41.0 and 39.2 m, respectively). On average, the aggressive interactions occurred near the aggressor's home range estimated borderline. It is possible that invader pressure increased due to the supplemented food and the territorial males were trying to keep other males from trying to cross their territory. The results of this study support the hypothesis that food distribution can affect aggressive behavior among male California ground squirrels. (Dominance & Resource Defense; Tues. 11:15 AM - 11:30 AM; NMM2)

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University of California - Berkeley & USDA/APHIS/WS/NWRC (bmitchel@nature.berkeley.edu)

We tested whether coyote barks and howls have characteristics that help identify animals by sex and individual. We recorded vocalizations from eight coyotes and produced sound spectrograms. We measured various spectrogram features, including vocalization duration, minimum frequency of the fundamental harmonic, maximum frequency of the fundamental harmonic, and location of the maximum and minimum frequencies. These measurements were analyzed using discriminant analysis to determine if coyotes have individually distinct vocalizations. We also examined whether vocalizations differed by sex and body size, and whether sounds from related individuals were similar. In a preliminary analysis of the recorded howls, discriminant analysis was over 70% accurate in classifying howls to sex and about 65% accurate in classifying howls to individual. The average minimum frequency of each animal's howls also decreased with its weight (R = 0.83, p = 0.006). We conclude that males and females vocalize differently, and that coyotes have individually distinct voices that could potentially be used for long-distance recognition. Recordings of coyote vocalizations can also potentially be used to determine the number of animals vocalizing and the sex of each animal. (Communication 2; Weds. 1:45pm-2:00pm; NMM1)

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Texas Tech University & USDA-ARS (frmitloe@ttacs.ttu.edu)

We sought to develop accurate and precise methods of behavioral data collection in feedlot cattle production systems that reasonably approximated continuous sampling. Standing, lying, feeding, drinking, and walking behaviors were examined from 224 h of continuous video from 24 cattle. Continuous behavioral sampling techniques (CO) were compared with scan sampling using 1, 5, 10, 15, 30 and 60 min intervals and time sampling for the first 10 min/60 min. Means for scan sampling methods did not differ in estimated percent duration of behaviors from continuous sampling except for scan sampling with a 60-min interval. Scan sampling with 60-min intervals differed from more frequent scan sampling intervals for all behaviors except lying. Scan sampling with short intervals (1 and 5 min) was highly correlated with CO for all behaviors. Behavioral means, standard deviations and coefficients of variation are presented along with estimates of required sample sizes. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of North Carolina - Wilmington (bruce@uncwil.edu)

Among live-bearing fish, females often show preferences for more colorful or larger males, or males that engage in ritualized courtship behavior. However, with eastern mosquitofish Gambusia holbrooki, the male characteristics influencing female mating preferences are not well understood. This study extends previous research on whether female Gambusia prefer unfamiliar males over males with whom they have had previous experience. Females were exposed to males for 3, 24, 36, 48, or 72 hours before a dichotomous choice test was conducted during which the female could choose between the familiar male and an unfamiliar male. Social behavior (proximity time, gonopodial thrusts, and nips) was recorded during the final 20 minutes of each exposure period to see if this would predict female preferences during the following choice test. Social behavior did not predict female choice after 3, 24, or 30 hours of exposure. After 48 hours, the more sexual behavior during exposure, the more females preferred the unfamiliar male. However, after 72 hours of exposure the reverse was true. Females may choose males based on previous social experiences that include sexual behavior and additional replicates will be conducted to determine the direction of this effect or the female characteristics associated with preferences. (General Poster Session; Tues. evening; Archer Hall Gym)

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Hampton College, Brookfield Zoo & Northwestern University (s-margulis@nwu.edu)

The barred sand bass, Paralabrax nebulifer, is a major component of the nearshore marine environment in the southern California Bight. They are highly sought after game fishes off the California Coast. During the summer they move higher in the water column and form large spawning aggregations in shallow areas. Complete knowledge of the behavior of the barred sand bass is necessary for the proper management of this increasingly popular resource. The life history and reproductive strategies of this species have been investigated, yet little is known about breaching behavior. Breaching was observed seasonally in a captive population at the Brookfield Zoo in Illinois. This study focuses on the relevance of breaching to spawning behavior. The daily activities and interactions of each individual were obtained in fifteen minute intervals. Focal observations recorded the duration and frequency of behavior along with proximity to others during breaching. The collected observations revealed that the larger basses paired and breached more frequently than smaller basses. Males and females were sited most frequently in proximity to members of the opposite sex. Other aspects of this behavior will be presented. (General Poster Session; Tues. evening; Archer Hall Gym)

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Ohio University (morrism@oak.cats.ohiou.edu)

Previous studies determined that vertical bars function as a sexual signal in swordtail fishes. Xiphophorus cortezi females prefer more bars, symmetrical bars and bars at higher frequencies, and yet a preference for bars over no bars had not been detected. We examined two hypotheses that could explain these results. First, X. cortezi females may prefer males with no bars over males with asymmetrical bars. Since past studies did not control for bar symmetry, preference for symmetry may have confounded preference for bars. Second, there could be a polymorphism in female preference for bars. We measured the strength of each female's preference for bars versus no bars, symmetrical bars versus asymmetrical bars and for the confounding situation of asymmetrical bars versus no bars. Some X. cortezi females consistently spent more time with males without bars over males with bars. The best explanation for the data is that there is a polymorphism in female preference for bars. (Mating & Repro. Success; Mon. 4:45pm-5:00pm; NMM1)

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Colby College (lsmorton@colby.edu)

Although infant caretaking has been well studied in captive colonies of squirrel monkeys and allomaternal behavior is widely reported to occur in captivity, data from field studies are sorely lacking. This study of a habituated squirrel monkey troop in Manu National Park in Peru revealed extensive allomaternal behavior by females without same-year infants. The infant caretaking was expressed by all non-maternal females in the study group. However, young pre-reproductive females and females with infant losses retrieved and carried infants significantly more than other adult females. Several adult females were also observed to nurse their charges. Adult and juvenile females in the troop were dye-marked and individually identified, making it possible to examine clique membership in relation to infant caretaking. Results showed that non-mothers carried infants of mothers in their own clique significantly more than would be expected by chance. Additionally, observations of coordinations and solicitations for infant caretaking between mothers and non-mothers involved only specific individuals within cliques. These patterns of caretaking and coordination suggest that allomaternal behavior in squirrel monkeys is more than simply a by-product of general female interest in infants. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Wisconsin - Madison (lrmoscovice@students.wisc.edu)

In primate species characterized by strict dominance hierarchies, social relations may influence how much individuals benefit from social learning. For example, subordinates may have less opportunities to learn or may show inhibition of learning, in the presence of dominant animals. This research examines the impact of social dynamics on social learning in a cooperatively breeding species, the cotton-top tamarin (Saguinus oedipus). Performance in a novel foraging task is examined in mated pairs. Success in the foraging task requires the use of spatial or visual cues to locate hidden food rewards and novel manipulations to obtain the rewards. Performance is assessed in two conditions: learning without social facilitation and learning with social facilitation by trained demonstrators. Preliminary results indicate much individual variability in learning without social facilitation. In contrast, consistently high levels of performance are found under social learning conditions. Reasons for this enhanced performance are presented, including decreases in neophobia and high degrees of behavioral coordination between demonstrator and observer. Evidence for similar phases of social learning across subjects is discussed. (General Poster Session; Tues. evening; Archer Hall Gym)

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Universidad Nacional Autónoma de México (amoyaho@miranda.ecologia.unam.mx)

Males of Xenotoca variata, a fish from Central Mexico, exhibit speckle-like spots on their flanks. Males from clear waters with few snakes, Thamnophis melanogaster, show more speckles than those from turbid waters. This study assessed whether snakes exposed to pairs of fish, from two populations, were attracted to the fish with more speckles. Snakes were tested twice in clear and turbid water. Snakes approached fish with more speckles F(1,67)= 4.62, p=0.035; preferentially in clear water F(1,67)= 5.99, p=0.017. There was no interaction between trait and water; neither significant differences between pairs of fish or between population of origin p>0.5. In the first trial, but not the second, combining clear and turbid water scores, snakes oriented firstly to the fish with more speckles G-test= 5.4824, p=0.0192. Attacks were directed to either fish. These findings confirm the hypothesis that fish bearing high numbers of speckles are more likely to attract snakes. Thus predation partly explains the geographic variation in number of speckles amongst populations of X. Variata. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Kentucky (jmoya2@pop.uky.edu)

Effects of cannibalism and territoriality are difficult to distinguish because the behaviors can cause similar patterns. Adult females of the Mediterranean tarantula, a burrowing wolf spider, are cannibalistic. Their dispersion pattern and other indirect evidence suggest that this spider is territorial. We tested the hypothesis of territoriality directly in two complementary field experiments. In a long-term experiment we placed an intruder in an artificial burrow within the hypothesized territory of a resident. Additional treatments controlled for possible effects of the manipulation on the introduced spider. The results indicate that the resident hunts in an area around her burrow and excludes conspecifics from the area, sometimes by cannibalizing them. We induced encounters between females in a short-term field experiment. Resident spiders tended to overcome intruders. Fights were more likely to escalate when spiders were of similar size, and cannibalism occurred only after escalation. These results are contrary to what would be expected if cannibalism solely were a means to capture prey. It is clear that in addition to providing energy to the successful cannibal, cannibalism in the Mediterranean tarantula is a component of territorial defense. (Dominance & Resource Defense; Tues. 10:45 AM - 11:00 AM; NMM2)

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State University of New York - New Paltz (KristinMLR@earthling.net)

Male crickets produce three types of vocalizations: Calling, rivalry and courtship songs. While calling song is used to locate the singer from a distance, the rivalry and courtship songs are used for more proximal interactions. Several researchers have reported differences in calling song characteristics between populations of Teleogryllus oceanicus in areas with different levels of parasitism by Ormia ochracea (e.g., Zuk et al, 1996; Simmons and Zuk, 1994). These observations may be due to differences in the competing selective pressures on survival (avoiding attracting parasitoids) and sexual selection (driven by female cricket song preference), or to age dependent results caused by increased mortality of older males who vary in singing ability. To test for age dependent effects on singing we paired male Teleogryllus oceanicus with sexually mature females and recorded their interactions on digital video and audio tape. We have begun to define the range of variation in the male's vocalizations during these interactions. Since older males are more likely to incur risks, we plan to compare the characteristics of these songs as a function of age. (General Poster Session; Tues. evening; Archer Hall Gym)

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Eastern Illinois University, Northwestern High School & University of Georgia (cfsjm@eiu.edu)

In addition to the recognized factors (meteoritic impact, volcanization, sea-level recession, etc.), egg and hatchling predation by an increased diversity of mammalian and avian species in the late Mesozoic played an important role in the extinction of non-avian dinosaurs. We argue that dinosaurs were predisposed to reproductive failure because they nested in exposed locations that they were obliged to actively defend. Further, we provide evidence that this strategy has seldom been practiced in the Cenozoic because it is viable in few habitats. The evolution of large size among avian species has been constrained by nest and hatchling predators, the largest species being limited to either grasslands, wetlands, and places with low predation pressure, particularly from mammals. We suggest that the hypothesis of avian and mammalian predation non-avian dinosaur nests be considered in concert with the other proposed reasons for the Cretaceous-Tertiary extinction. (General Poster Session; Tues. evening; Archer Hall Gym)

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Universidade de Brasília (lauramuniz@hotmail.com)

South American guira cuckoos (Guira guira) breed communally, with several females contributing clutches to a joint nest. Ecological factors may affect individual and communal clutch sizes, interval between repeated nestings, and egg and nestling elimination by group members. Because opportunities to reproduce halt at the end of the rainy season, we predicted that: (1) egg volume and total clutch size would increase within seasons; (2) ovicide and infanticide would be higher in the beginning of the season; (3) interval between repeated nestings would decrease; and (4) egg laying interval to complete communal clutches would decrease. We found that, as the rainy season progresses, there is a slight increase in egg volume; and that the interval between repeated nestings shortens. No other seasonal effects were found for other reproductive variables. The destructive components of reproduction in this species (ovicide and infanticide) may be somewhat independent of ecological variables, and more sensitive to social dynamics within groups. On the other hand, egg production variables may be influenced more strongly by ecological and/or physiological conditions. (General Poster Session; Tues. evening; Archer Hall Gym)

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James Madison University (murphycg@jmu.edu)

Despite intense interest in mate choice, relatively little is known about how individuals sample prospective mates. I investigated mate sampling by female barking treefrogs (Hyla gratiosa). Females choosing mates in natural choruses did not move between males but instead mated with the first male they approached closely. Most females mated with the male closest to them at the start of their mate-choice process, and females were more likely to mate with the closest male when the distance to other males was large. These observations are consistent with two hypotheses: 1) females do not sample potential mates but instead mate with the first male they detect above the background chorus noise, and 2) females sample two or more males simultaneously. I distinguished between these two hypotheses by conducting a playback experiment in which I offered females a choice between two calls, only one of which was detectable above the background chorus noise at the female’s release point. Females did not prefer the detectable call, as would be expected if females mated with the first male they detected above the background noise. These results implicate simultaneous sampling of several males whose calls are detectable above the background chorus noise. (Mate Choice 4; Weds. 9:45 AM - 10:00 AM; NMM2)

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University of California - Los Angeles (pnarins@ucla.edu)

Temporal and spectral characteristics of vocalizations of a multispecies frog assemblage in the Queen Sirikit Botanic Garden near Chiang Mai, Thailand were examined during the beginning of the breeding season in May 1997. Calls of eight frog species were recorded to determine the extent of temporal, spectral and spatial separation observed among heterospecifics. Results show that some of the frogs sampled displayed clear temporal separation from the group (e.g., Rana pileata), others exhibited spectral separation (e.g., Chirixalus doriae), and still others were spatially separated from or on the edge of the group (e.g., Microhyla butleri). In addition, all species studied exhibited site fidelity on successive nights over the sampling period. Our observations suggest that frogs in this Old World disturbed community produce a variety of calling patterns that often results in reduction of mutual acoustic interference. Supported by UCLA Office of Instructional Development and NIDCD Grant no. DC00222 to PMN. (Communication 1; Weds. 9:30 AM - 9:45 AM; NMM1)

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University of Sao Paulo & Colby College (crbevier@colby.edu)

Individual variation in antipredator behavior may be influenced by ecological factors, such as ambient temperature and predation pressure, and by intrinsic factors, such as physiological condition. We tested the hypothesis that both types of factors interact to induce a particular antipredator response in the treefrog, Scinax hiemalis. This eurythermic species exhibits a passive response by either feigning death or freezing, or an active escape response when disturbed by predators. We examined the responses of 24 adult male S. hiemalis to simulated predation in the laboratory at 10, 15 and 20C. In addition, responses from a single stimulus were compared to those from a series of stimuli. We determined physiological condition from measures of body length and mass, jumping performance, aerobic metabolic scope, and estimated energy reserves. Temperature had the most influence on antipredator behavior, with more frogs exhibiting passive responses at 10C than at higher temperatures. If stimulated more than once, the proportion of active responses increased at all three temperatures. Larger individuals were more likely to exhibit an active response, but no mass-independent physiological variables were related to response type. These results suggest that frogs respond to both extrinsic and intrinsic factors that may affect their behavioral performance. (Anti-predator Behavior; Tues. 5:00pm-5:15pm; NMM2)

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University of Illinois (jjnesbit@life.uiuc.edu)

Why tropical birds lay a small, usually 2-egg, clutch is a classical life history enigma. Many suggested hypotheses assume small brood size maximizes adult or nestling survival probability. How brood size affects juvenile survival probability after fledging is poorly understood. I investigated the effect of brood size on the probability of juvenile survival to fledging and dispersal of Spotted Antbirds (Hylophylax naevioides), a neotropical passerine. Fledging success was equal for juveniles raised either alone or with a sibling. Per capita parental feeding rate of nestlings did not differ with brood size; juveniles from different brood sizes fledged at the same mass and stage of development. After fledging, juveniles without a sibling showed a trend for greater post-fledging survival probability relative to juveniles with a sibling (86% versus 50% p = 0.09). Parents divided the care of their fledged brood when two offspring were present. In contrast, juveniles without a sibling were attended by both parents and may have received more food or better protection from predators. The relationship between parental care, brood size, and post-fledging juvenile survival may be of particular importance to life history evolution of tropical birds and is being investigated further in an experimental study. (Parental Care 1; Sun. 11:45 AM - 12:00pm; NMM1)

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Cornell University (nn12@cornell.edu)

The long history of human cohabitation with domestic cats offers the possibility of testing the effect of artificial selection on signaling behavior. Based upon exposure to recordings of single vocalizations (meows) obtained under controlled conditions, human subjects in this study performed a forced-choice classification task between five behavioral contexts of vocal production. The contexts ranged from affiliative, agonistic, distress, to food- and obstacle-related. Subjects also rated their degree of familiarity with cats along three different scales. Responses were scored for accurate classification of both the context of call production and of the affective tone of the calls, positive or negative. The results show an effect of experience on call classification, with familiar human subjects outperforming naive ones on both the context and affect measures. There is also evidence of a differential effect of familiarity: where reading of affect shows only a modest positive correlation with experience, classification of context improves more sharply. We therefore suggest that the former is based on a general pattern of affect communication in mammals, and that the learning of higher-order classifications is in turn "scaffolded" upon that pattern. (Communication 2; Weds. 2:00pm-2:15pm; NMM1)

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San Francisco State University & College of Charleston (sfbaffo@aol.com)

The Flammulated Owl (Otus flammeolus) is an environmentally sensitive, insectivorous species that occupies commercially valuable ponderosa pine (Pinus ponderosa) forests in the western United States. Little is known of its winter range, and some authorities speculate that it winters near breeding grounds rather than migrating to Mexico, as is usually assumed. To conservatively test this migratory ambiguity, we erected a series of hypotheses to address the possible existence of alternative migration strategies. We collated 379 specimen or photographic records and 756 published records (not substantiated by specimens) from the U.S. and Canada. We predicted a positive correlation between latitude and the Julian dates at which Flammulated Owls were first encountered in the spring and a negative correlation between latitude and the Julian dates of last encounter in the autumn. Although our prediction of a correlation between latitude and date appears supported for the spring, fall records are rather uniformly distributed in this respect. We cautiously interpret this asymmetrical pattern as suggesting that some individuals indeed attempt to overwinter in the north, but few survive. With the evidence provided or available, we conclude that this species probably migrates latitudinally, but the occurrence of altitudinal and partial migration cannot be completely refuted. (General Poster Session; Tues. evening; Archer Hall Gym)

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State University of New York - New Paltz (tomnolen@mad.scientist.com)

It is not clear if female crickets use variation in the male's courtship song to discriminate between possible mates. However, certain acoustic elements of courtship song are more important than others for a male's courtship success (Libersat et al, 1994; Balakrishnan and Pollack, 1996). One hypothesis for the function of courtship song is that it is a cue indicative of a male's ability to incur the risk of attracting both parasites as well as rival males. If this is true in Teleogryllus oceanicus, the trill of the courtship song should share temporal similarities to the trill of the calling song since the later is attractive to male crickets (Pollack, 1982). The chirp of courtship should have temporal qualities similar to that found in calling song, which is attractive to parasitoid flies. Using digital audio and video analysis we are comparing the song components the male presents during successful vs. unsuccessful courting attempts. Since older males are more likely to accept risks, we also plan to compare the characteristics of these songs as a function of age. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Virginia (cln3b@virginia.edu)

The risk of disease is likely to vary with social and ecological parameters, leading to predictions for cross-species comparative tests. We used mean values of white blood cells in healthy zoo animals as measures of risk, based on the assumption that higher baseline values will be found in species that typically experience greater risk of acquiring disease. These data were used to investigate three hypotheses in primates: disease risk increases with (1) group size and population density, (2) terrestriality, e.g. through greater proximity to soil-borne pathogens, and (3) increased numbers of mating partners. After controlling for phylogeny, we found some support for all three hypotheses, but support for the sexual hypothesis was strongest: several classes of white blood cells increased with the duration of estrus, the number of mating partners and relative testes size. Results remained significant in a smaller dataset restricted by sex and in multiple regression analyses that included proxies for the non-sexual hypotheses. We therefore conclude that mating behavior, possibly in combination with other factors, is associated with disease risk in primates. Hence, the benefits that females obtain by mating with multiple males may be offset by the costs of infectious disease. (Immune Systems & Behavior; Weds. 2:00pm-2:15pm; NMM2)

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San Francisco State University (OglesbyA@aol.com)

A general ecology and behavior study was conducted in the protected old growth forest of Irish Creek, Belize. Transects were established for a black howler monkey habitat survey, population census, and behavior assessment in a 1.5 x 2.5 km block of varying seasonal forest. Approximately 25 troops occupied a variety of habitats, ranging from swamp to lowland moist evergreen forest. Activity budgets were comparable to previous data gathered on the species with 62% of daily time spent resting, 17% feeding, 14% vocalizing, 7% traveling and 1% urinating/defecating. High percentages of vocalization may be partly due to human presence. Average troop size was 6-7 individuals with a maximum of 16 howlers in a troop. Many multi-adult male troops were observed, possibly because of high resource availability and moderate amounts of natural predation. At least 2 troops of spider monkeys, Ateles geoffroyi, also inhabited the site, allowing interactions with a sympatric species. With the habitat of this threatened black howler species increasingly fragmented, the conservation implications of maintaining protected sites such as Irish Creek are of great concern. (Applied Animal Behavior; Tues. 2:00pm-2:15pm; Sale)

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Boston University (sjoliver@bio.bu.edu)

Mate choice based on male behavioral and acoustic characteristics has been well studied in terrestrial vertebrates, but has been largely lacking for fishes. A tagged population of male and female Dascyllus albisella (Pisces: Pomacentridae) was observed for 113 hours using focal animal sampling during Aug.-Oct. 1997, and Mar.-June 1998. Male phenotypic, behavioral, and territorial characteristics were measured and compared to the mating success of individual males. No phenotypic or territorial characteristics were correlated with male mating success. Male courtship rates were significantly correlated with male mating success, both in terms of mean clutches per cycle and total number of eggs. Peak calls per five minutes of observation was the best indicator of mating success. Peak calls per 10 minutes, and mean calling rate (calls per minute) were also significantly correlated with success, but less strongly than for five-minute bins. Male reproductive success in a given cycle was significantly higher for males that had a clutch in the preceding cycle, suggesting an effect of current success on future success. We suggest that females are using the behavioral cues of courtship and parental effort as an indication of future parental effort. (Mate Choice 2; Sun. 2:15pm-2:30pm; NMM2)

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Arizona State University (d.m.orsetti@asu.edu)

When females mate repeatedly with the same male, it presents an intriguing problem for evolutionary biologists due to the high costs and not very apparent benefit to females. Yet, this behavior must have higher benefits than costs to be maintained by natural selection. What could these benefits be? We examined the possible benefits of repeated matings in the Colorado potato beetle (Leptinotarsa decemlineata). The two hypothesized benefits that we tested were the sperm material benefits and non sperm material benefits hypotheses. We mated virgin females to a single virgin male varying numbers of times and recorded egg production, larva production, hatch rate, and sperm stores in females. Both hypotheses predict an increase in fecundity with an increase in matings, while the sperm material benefits hypothesis also predicts an increase in sperm stores with an increase in matings. There was, however, no such relationship in any fecundity or sperm stores data; therefore we conclude that neither material benefits hypothesis is supported. Interestingly, there was a significant decrease in hatch rate with an increase in matings, making repeated matings even more puzzling. With no apparent material benefit, it is possible that repeated matings have a role in mate choice by females. (Mating & Reproductive Success; Mon. 4:00pm-4:15pm; NMM1)

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Cornell University (owren@cornell.edu)

Examining likely vocal-production mechanisms underlying the acoustics of species-typical calls is critical to understanding the functional significance of such sounds. Here, we argue that the so-called "tonal," "arched," and "undulated" screams proposed to represent three discretely different call-types in the rhesus monkey (Macaca mulatta) vocal repertoire are closely, if not indistinguishably linked from a production standpoint. Acoustic features thought to differentiate them actually routinely appear in each, including sidebands produced when underlying periodic, but highly unstable vocal-fold vibrations of these screams are amplitude-modulated. Sidebands are a very general phenomenon in nonhuman signaling, and can give a sound the appearance of stable harmonic structure. They are instead the product of nonlinear interactions that are typical of systems like the vocal folds, which are driven, coupled oscillators. As such, vocal-fold vibration patterns show exquisite sensitivity to arbitrarily minute fluctuations in underlying production parameters, in turn suggesting that the purported distinguishing features of these sounds are not under close control of the calling animal. These effects are demonstrated and quantified in screams produced by rhesus monkeys recorded during the course of social interactions with familiar conspecifics in naturalistic settings.

(Communication 1; Weds. 11:30 AM - 11:45 AM; NMM1)

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University of Wisconsin-Madison (oyegbile@students.wisc.edu)

How an animal approaches an aggressive encounter can be heavily influenced by the results of previous encounters. Therefore, an animal can be more likely to lose an encounter if it recently lost an encounter (loser effect) and can be more likely to win an encounter if it recently won an encounter (winner effect). We are testing the likelihood of winning a future (final) aggressive encounter after winning three, two, one or no resident-intruder encounters in the mouse Peromyscus californicus. During the initial encounters, the resident males are more likely to win encounters because the intruders are mildly sedated. During the final encounter, residents are less likely to win because the intruders are also previous winners and larger in size. Lastly, we are comparing the territorial P. californicus to a less territorial species, P. leucopus, to determine if the winner effect is associated with territoriality. Testosterone levels will also be compared between groups. Preliminary results suggest that the winner effect increases depending on the number of aggressive encounters an individual has experienced and that the winner effect can occur in rodents. (General Poster Session; Tues. evening; Archer Hall Gym)

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Rutgers, the State University of New Jersey (palestis@eden.rutgers.edu)

Expanding gull populations have had a negative impact on terns due to both nest predation and nest site competition. The objective of this study was to examine variation in antipredator responses of common terns (Sterna hirundo) to three species of gulls. In previous studies herring gulls (Larus argentatus) were the most frequent nest predators at tern colonies, and tern antipredator behavior was biased toward herring gulls. We observed the responses of common terns to gulls at Pettit Island, New Jersey, over three field seasons. A pair of great black-backed gulls (L. marinus) nested at Pettit and were the only gull species observed preying on tern young. Terns responded to great black-backs more frequently than to herring and laughing gulls (L. atricilla), even when controlled for gull behavior. Additionally, responses to great black-backs were more aggressive and caused more terns to fly up from their nests than responses to other gulls. The antipredator behavior of common terns appears to be quite flexible, and can be modified by experience with particular species. (General Poster Session; Tues. evening; Archer Hall Gym)

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Duke University (kkp1@duke.edu)

Predator-prey interactions based on sensory information are limited by physical constraints on sensory transmission. Prey responses are therefore dependent upon environmental context. Context changes constantly in estuarine environments. Flow rate and direction, turbulence and turbidity, temperature, salinity and structural complexity change continuously with the tides. If one overlays this dynamic with migratory predators that are both nocturnal and diurnal, it is clear that the level and importance of sensory information available to prey is constantly changing. This study describes the response of an estuarine fish, Fundulus heteroclitus, to chemical and visual predator cues. We describe responses to visual and chemical cues and their interaction in the laboratory. While visual cues depend upon light level, responses to chemical cues are independent of light levels and stereotyped. Responses to cues depend on the order of presentation. The cue received first, suppresses or alters the response to the second cue. Interaction between cues can be measured as a change in the absolute level of responsiveness. Predator-prey interactions should be considered in several sensory modalities, especially when dealing with highly dynamic habitats. (Anti-predator Behavior; Tues. 4:45pm-5:00pm; NMM2)

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University of New Mexico (tparker@unm.edu)

A key prediction of the good genes model of sexual selection is that paternal condition is inherited. Tests of this prediction are easily confounded by the possibility of adaptive differential maternal investment. Empirical and theoretical evidence indicates that females may increase investment in a reproductive bout when mated to an attractive male. I am studying both inheritance of paternal condition and differential maternal investment in the red junglefowl. In this species, a number of studies have demonstrated that females prefer large-combed males as mates. I artificially inseminate laying females with sperm from either a large or small-combed male ('genetic father'). During this fertile period, these same females are housed with a sterile (vasectomized) male ('social father') with either a large or small comb. Comb sizes of genetic and social fathers both positively affect offspring condition and offspring comb size. These preliminary results indicate that, while there is a good genes effect in the red junglefowl, adaptive maternal effects also can play a role in the relationship between the phenotypes of offspring and their fathers. (General Poster Session; Tues. evening; Archer Hall Gym)

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Yerkes Regional Primate Research Center & Emory University (parr@rmy.emory.edu)

The ability to understand the emotions of others is one of the most important factors involved in regulating social interactions in many primate species. Previous studies have demonstrated the ability of chimpanzees (Pan troglodytes) to categorize their facial expressions, but none have examined whether chimpanzees understand the emotional meaning of these expressions. This study examined emotional awareness in chimpanzees using a novel version of the matching-to-sample task, here called matching-to-meaning because the similarity between the matching pair was based on emotional meaning, not perceptual features. Chimpanzees viewed short videos depicting positive and negative emotional events, and were required to select one of two conspecific facial expressions that conveyed an emotional meaning similar to that in the video. Three subjects spontaneously associated negative facial expressions (screams and bared-teeth displays) with scenes of veterinary procedures, inje!

ction needles, and distressed conspecifics, and positive facial expressions (play faces) with scenes of favorite food and objects. These results provide evidence for basic emotional awareness in our closest-living relative that is not based on training or reinforcement history. (W.C. Allee Competition; Mon. 2:15pm-2:30pm; Sale)

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Disney's Animal Kingdom & Cornell University (Sarah.R.Partan.-ND@Disney.com)

The vocal communication system of the African elephant (Loxodonta africana) has been studied in the wild, but has rarely been examined in detail in a controlled, captive environment. In an effort to help clarify the function of their vocalizations, we have collected data on visual behaviors that precede, accompany and follow the infrasonic vocalizations of eight captive African elephants (2 males, 6 females). Using focal animal sampling, we video recorded the animals as they roamed through their naturalistic 6.7 acre enclosure, while simultaneously capturing their vocalizations on recording collars worn by the elephants. Each collar houses a small condenser microphone and a radio transmitter which sends the signal to a DAT recorder for preservation and analysis. Six of the eight elephants are habituated to wearing these collars, which are placed on the animals in the morning and removed each evening by the elephant keeper staff. Preliminary associations between vocalizations, group composition and behavioral context (group movement, approaches, leaves, bathing, dusting, etc.) will be presented. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Louisiana - Lafayette (meg0846@louisiana.edu)

Foraging behavior has a major influence on future fitness of individuals and, although it may be stereotyped with a strong genetic basis, it may also be strongly influenced by prior experience. This study tested hypotheses concerning the effects of learning and, possibly, heredity on foraging behavior in red-backed salamanders. Ingestively naïve neonatal salamanders were monitored for the first three times that they were exposed to prey. These salamanders were again monitored as yearlings for the first three times that they were exposed to a novel prey item. In addition, adult females (maternal parents of previously tested neonates and yearlings) were monitored for the first three times that they were exposed to a novel prey item. I tested four parameters for each experiment: (a) time to first capture, (b) intercapture interval, (c) number of captures in 10 minutes, and (d) accuracy. Neonates and yearlings showed improvements in all four parameters over the three feeding trials. Adult females improved over the feeding trials in all parameters but accuracy. In addition, there were significant clutch effects for all four parameters, suggesting a heritable component to foraging ability. (Foraging; Tues. 1:30pm-1:45pm; NMM2)

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State University of New York - Stony Brook (spochron@ms.cc.sunysb.edu)

After accounting for body weight and season, the testicular volume of adult male sifakas varies dramatically across individuals. In the non-breeding season, the gonadosomatic index (the testicle-volume-to-body-size ratio) in males over the age of two ranges from 1.6 to 8.4 cc, a 5-fold difference. We investigate social factors underlying this variation using 12 years of behavioral and morphometrics data. Contrary to predictions based on sperm competition theory, as the sex ratio became male biased, the gonadosomatic index (GI) decreased, after using residuals to account for seasonal variation. We attribute this to females experiencing sperm as a limited resource. In support of this, we found that during the breeding season, sifaka groups contain significantly fewer females and the sex ratio is significantly female biased. We then attempted to find support for sperm competition in groups containing either one breeding female or two breeding females, expecting that as the sex ratio became more male biased in these groups, relative GI would increase. We found no such support. Males increased their GI significantly with rank, after accounting for season. Because aggression occurs infrequently in sifaka groups, male rank was based on time spent near females. Males who spend more time than their competitors near females have significantly larger GI measures, even after season is accounted for. Age cannot explain any of these relationships. We place these findings in context with lemur life-history characteristics and Madagascar’s challenging ecosystem. (Social Behavior 2; Tues. 5:15pm-5:30pm; NMM1)

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University of Arizona (jpodos@u.arizona.edu)

According to classical theories of speciation, animal mating signals may diversify as incidental or secondary byproducts of adaptation to divergent ecologies. Evidence in support of this point, however, has been lacking, particularly in wild populations. Here I show, in Darwin's finches of the Galapagos Islands, that the structure of vocal mating signals covaries with beak morphology and body size, on both intra- and interspecific levels. In particular, birds with larger beaks and body sizes are found to produce songs with comparatively slow rates of syllable repetition and comparatively narrow frequency bandwidths. The direction of this covariance is consistent with the hypothesis that vocal tract morphology has constrained vocal evolution, with different beak morphologies differentially limiting birds' abilities to modulate vocal tract configurations during song production. These data help to explain patterns of diversification in Darwin's finch song evolution, and more generally illustrate how ecological diversification and corresponding morphological adaptation may drive the evolution of mating signals and reproductive isolation. (Evolution of Signals; Tues. 10:30 AM - 10:45 AM; NMM1)

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(absc@ladogtraining.com)

Aggressive reactivity which follows the experience of an electric shock appears to be based on an inherent tendency for an animal to react defensively when pain is experienced. Applied animal behaviorists serving dog owners have made note of the possible connection between an animal's experience of electronic shock and the elicitation of aggression. Nonetheless, individuals who work professionally with companion animals (e.g. veterinarians, trainers, breeders) but who lack training in animal behavior remain ignorant of the possibility that aggression in a dog can be elicited due to the pain caused by an electronic shock collar. To this date, no report exists in the veterinary or animal behavior literature which focuses specifically on the fact that electric shock can cause some dogs to become aggressive. In this report, I report seven cases where electric shock delivered from a training collar was the likely cause undelying a dog's attack on a human. Data from each case are presented. Pros and cons of the use of electronic collars as training tools in behavioral modification for dogs are discussed. (Applied Animal Behavior; Tues. 1:45pm-2:00pm; Sale)

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University of Maryland (tp35@umail.umd.edu)

Despite the large number of published studies examining cooperation, few have documented cooperation among unrelated individuals. Greater spear-nosed bats (Phyllostomus hastatus) provide a favorable system for examining cooperation independently of kin selection. Although female groupmates are not closely related to each other, they often remain with the same social group for decades, in which they forage cooperatively and give birth synchronously. Over two birth seasons, I videotaped six wild groups in a cave on Trinidad, West Indies, and two captive groups at the National Zoological Park, Washington, DC. Each group comprised eight to 25 females that shared a roosting cavity with their singleton pups and only one adult male. When most of the mothers departed the cave at night to forage, they left their pups behind, often clustered with one or more lactating mothers in the group. I will address patterns in the cooperative behaviors of these mothers that stayed behind, as well as the characteristics that predicted which mothers groomed the pups of their groupmates, nursed them, and retrieved them from nearby spots on the cave ceiling. Supported by PHS 5 F32 HD07928-03 and NSF IBN-9209401. (General Poster Session; Tues. evening; Archer Hall Gym)

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National Zoological Park (dpowell@nzp.si.edu)

Variance in reproductive output among female mammals is most likely to be limited by nutrition rather than by the availability of mates. Feeding strategies that maximize nutrient intake should evolve in response to seasonal changes in food availability and quality. Foraging strategies of individuals may be affected by a system of social dominance and food quality. I assessed the impact of social dominance, seasonality, and home range on foraging behavior and energy intake in a population of feral horses using behavioral observations and an index of digestible energy intake (fecal DAPA). There was a significant effect of year and dominance on foraging time such that mares spent slightly more time foraging in 1998 versus 1997. Dominant mares spent more time foraging than subordinate mares. There was also a significant effect of home range on mean group foraging time. There were no effects of dominance or home range on diet quality; however, there were significant effects of season and month on DAPA measures. These results indicate that for feral horses, social dominance may have an effect on feeding ecology in terms of foraging time but not energy intake. Home range characteristics (e.g. degree of biting fly harassment) may also affect foraging time. Finally fecal DAPA can be used to track seasonal changes and home range differences in habitat quality. (Dominance & Resource Defense; Tues. 11:30 AM - 11:45 AM; NMM2)

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University of California - Davis (vpravosudov@ucdavis.edu)

Food-caching birds wintering in temperate climate rely on two sources of energy for their survival: internal body fat and external food caches. Whereas access to body fat is unlimited, caches may not be recovered for hours, days or even months. Birds rely on spatial memory to recover previously hidden caches. Failure to find caches may potentially result in death from starvation. Cache recovery may be more critical for birds that forage in harsh conditions than for those foraging in mild conditions. We hypothesized that birds should have a better spatial memory and be more accurate at recovering their caches when food is limited and variable. To test our hypothesis, we compared the cache recovery behavior of 24 wild-caught mountain chickadees (Poecile gambeli). Half of the birds were maintained on limited, variable food and the rest were maintained on unlimited food for 60 days. We then tested their spatial memory by allowing birds form both groups to cache food in the experimental room and then recover their caches 5 hours later. Our results indicated that birds maintained on variable food made significantly fewer mistakes when recovering their caches compared to birds maintained on unlimited food. (Animal Learning & Cognition; Tues. 9:45 AM - 10:00 AM; Sale)

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Emory University (signe@rmy.emory.edu)

Food sharing has been observed in wild and captive chimpanzees. We assessed the amount of food sharing in dyads where two individuals voluntarily separated themselves from the rest of the group to participate in the experiments. We presented 7 kin and 12 non-kin dyads of female chimpanzees with two experimental conditions: In the "sharing" condition stakes were high (yogurt), but risks were low because subjects were separated by mesh. In the "competition" condition stakes were lower (nut), but risks were higher, because both partners were in the same cage. In yogurt tests females did share - usually with a strong bias in favor of one partner - and the identity of this individual varied between trials. It was not possible to predict who obtained more yogurt from the nut tests, nor from pant-grunting. That clear food sharing was rare within trials is probably attributable to the fact that low-ranking individuals often got hold of the food, while high-ranking individuals did not seriously try to take it away from them. Sharing was not more pronounced in kin than in non-kin dyads. (Social Behavior 1; Mon. 3:15pm-3:30pm; NMM2)

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University of Louisiana (Heap74@aol.com)

Clutton-Brock and Parker (1995) stated that "in some animals, males punish females that .... associate with other males, with various forms of physical violence". Red-backed salamanders, Plethodon cinereus, often associate in intersexual pairs (as partners) on the forest floor in Virginia. We examined the responses of females toward male partners that had either associated with a strange female (fickle) or had not associated with a strange female (faithful) during the courtship season. The females were significantly more aggressive (e.g. biting) toward fickle male than faithful male partners. The fickle males were significantly more submissive toward their partners than were faithful males.

We also examined the responses of females toward unfamiliar males that had either associated with a strange female (fickle) or had not associated with a strange female (non-fickle). The females were significantly more aggressive toward fickle male than non-fickle male strangers. The fickle males were significantly more submissive toward the females than were non-fickle males. Thus, the female salamanders appeared to "punish" both partners and unfamiliar males that have spent time with another female. (Mate Choice 3; Mon. 2:00pm-2:15pm; NMM1)

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Utah State University (stan@cc.usu.edu)

There is slight but growing realization among scientists and managers that foraging behavior is important in livestock production. Often, the influence of behavior on production of cattle, sheep, and goats is not obvious because the outcomes are distant in time and space. Experiences early in life, for instance, can impact how much of particular foods animals eat years later when fed in confinement and on pastures. That, in turn, influences productivity - body condition, milk production, post-partum interval. Experience also influences which foods animals learn to eat, and moving animals from familiar to unfamiliar environments can lead to dramatic decreases in production, and it can lead to over-ingestion of toxic plants on grazing lands. The mix of foods available also influences animal production. Variety is the spice of life because animals satiate - get sick and tired - on familiarity and flourish on diversity. Palatability is the ongoing interaction between a food's flavor and its postingestive effects, influenced by an animal's current nutritional state and its past experiences with the food. Unfortunately, scientists and managers often are unaware of how these relationships - experience and variety - influence research results and profitability. For the scientist, variation among individuals due to past and ongoing experience is simply "noise" in the data. For the manager, variation due to experience represents losses - unknown to the producer - in productivity. I will provide examples of how experience influences food and habitat selection, and discuss the implications for research and management. (Applied Animal Behavior Symposium; Tues. 4:15pm-4:45pm; Sale)

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(FredPUT@aol.com)

Studies were conducted on tail-position avoidance learning in Anolis sagrei, utilizing a yolk-control procedure. This species exhibited avoidance learning and retained the learned response after 6 hr of training. Inhibition of brain RNA synthesis resulted in a significant impairment of learning. Avoidance learning is accompanied by significant increases in neuronal RNA and protein synthesis in the basal forebrain suggesting an active role for this telencephalic region in mediating the learning process in this species. The relationships between learning, molecular syntheses and localization of brain function will be discussed. (General Poster Session; Tues. evening; Archer Hall Gym)

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Chicago Zoological Society (quintana@mote.org)

Associations of resident and non-resident bottlenose dolphins were studied to provide insights into the selective pressures influencing the social organization of the species. Monthly photo-identification surveys were conducted from June 1996 to May 1997 in the Cedar Keys, Florida. Surveys were standardized to cover the entire study area, and survey routes were used to minimize a heterogeneous sampling. Resightings of identifiable dolphins were used to determine whether individuals were residents or non-residents, and to quantify associations. A dolphin was considered a resident if it was seen more than 6 months, and a non-resident if it was seen between one and five months. Of the 219 individual identifiable dolphins, 41 were characterized as residents and 170 were characterized as non-residents. Associations between residents and non-residents were mostly low level, and did not show any pattern between individuals of different gender or reproductive condition. In contrast, associations among residents were higher within sexes than between sexes. Associations among males and among females appear to result from individual preferences, because dolphins only associated with particular individuals even when they shared similar ranges with the study area. Associations may provide a greater protection from open water predators, and a greater access to mates. (Social Behavior 2; Tues. 4:45pm-5:00pm; NMM1)

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Cornell University (lsr1@cornell.edu)

Newly emerged adult Polistes wasps are naive foragers, but have experienced plant allelochemicals in their larval diet. To determine whether predators are ‘induced' to prefer prey with higher or lower concentrations of allelochemicals based on their feeding experience as larvae, we raised generalist paper wasps on diets of palatable painted lady or unpalatable buckeye caterpillars. After the period of induction, wasps were given a choice between the two visually similar caterpillars. We examined the effects of larval diet on the adult forager's subsequent choice of prey and the response of the larvae to novel prey. Our results demonstrate that adult forager's subsequent choice of prey is dramatically affected by larval feeding experience. Although all wasps rapidly shift to more palatable prey when given a choice, those individuals reared on unpalatable prey continue to capture it at much higher rates than other wasps. However, larvae do not passively accept whatever prey is brought to the nest and their rejection of prey affects subsequent foraging choices by the adults. Our data is a unique link to understanding how wasp's predatory decisions off the nest are affected by individual experience and by feedback from feeding larvae on the nest. (Predator/Prey; Mon. 1:30pm-1:45pm; NMM2)

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Tufts University (MREED@TUFTS.EDU)

The basic premise of models predicting animal settlement patterns is that, when choosing among potential territories or home ranges, an individual should select the site that maximizes expected fitness. When information site quality is imperfect, the efficacy of each decision should be based on the information available. For sedentary, territorial animals, it may be relatively easy to gain information about the quality of adjacent territories. But many animals experience their environment on a much larger, landscape scale, such as during migration. Habitat selection at this larger scale has received little theoretical or observational interest until recently. I will review empirical evidence for prospecting at the landscape scale and discuss the patterns that appear across taxa in prospecting for both natal and breeding dispersal. I will then examine the potential implications of prospecting, and other behaviors such as dispersal inhibition, for population dynamics. In particular, I will focus on metapopulation dynamics and models, because many of the species that view their world on a landscape scale and engage in breeding site selection are likely to exist in some form of metapopulation structure. (Dispersal Symposium; Sun. 3:00pm-3:30pm; Sale)

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University of Guelph (preid@ovcnet.uoguelph.ca)

Avoidance learning has received an enormous amount of attention from learning theorists over the decades because it is a classic example of the complex interplay between instrumental and classical conditioning. Animals are quick to escape aversive stimuli and come to learn the associated warning signals so they can avoid the situation altogether. Avoidance responding is acquired rapidly, is extremely durable, and is tricky to extinguish. Applied animal behaviorists frequently encounter real world examples of avoidance learning when analyzing pet behavior problems. Behaviors displayed in the context of fear and aggression, in particular, appear to be maintained by the perceived avoidance of danger or conflict. A thorough understanding of how avoidance responding is acquired and maintained enables applied animal behaviorists to alter the established behavioral strategies in these animals, through techniques such as counter conditioning, stimulus flooding, response blocking, and safety signal conditioning. Application of these techniques will be demonstrated through case studies. (Applied Animal Behavior Symposium; Tues. 3:45pm-4:15pm; Sale)

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State University of New York - Buffalo (orc@buffalo.edu)

Theoretical models suggest that, under certain conditions, males may adjust their parental effort in response to low levels of paternity within their brood. Sunfish from the genus Lepomis possess attributes that make them ideal for a study of cuckoldry and male parental care: (1) parental care is provided by the male alone, (2) eggs are fertilized externally, and (3) an alternative male phenotype exists which does not provide parental care but instead sneaks fertilizations in the nests of parental males. However, few studies have used molecular markers to analyze patterns of paternity in these fish. In this study, I investigated the fertilization success of sneaker pumpkinseed sunfish (Lepomis gibbosus) males using microsatellite markers, and explore patterns of paternal effort and paternity. Parental males decreased parental effort with the age of their brood, which may increase the probabilities of a subsequent breeding attempt. Large males have deeper nests than small males and this may affect intruder pressure. The effects of nest depth on intruder pressure and male parental care will be explored. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Manitoba (umrobbtl@cc.umanitoba.ca)

We set out to determine if body size influenced an individual’s ability to tolerate hypoxia and how this in turn will reflect habitat selection decisions of a piscine predator and prey population. We hypothesized that small fish will use hypoxic areas as a refuge from a larger piscine predator due to an allometric scaling relationship of tolerance to hypoxia. Physiological parameters including hematocrit, hemoglobin concentration and ventilation frequency were measured in response to hypoxia and these were used to determine tolerance. Based on the proposed allometric relationship, an ideal free distribution model was developed to predict the distributions of both a predator (yellow perch, Perca flavescens) and prey population (fathead minnow, Pimephales promelas) in an environment with spatially and temporally fluctuating dissolved oxygen concentrations. All of the physiological variables measured suggested a size sensitive relationship in which the smaller prey were better able to withstand hypoxic conditions. Using these data in our model it predicted that hypoxia can generate predator-free refuges. (Habitat Choice; Mon. 4:15pm-4:30pm; Sale)

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The neuroendocrine mechanisms for alloparental behavior (parenting another's offspring) are poorly understood. Alloparenting is ubiquitous among human cultures, but rare in non-human primates. New World primates of the family Callitrichidae are an exception. Callitrichids, including common marmosets, dwell in nuclear families and all family members help care for infants. This study tested the hypothesis that prolactin, an adenohypophysial hormone correlated with alloparenting in many birds and mammals, promotes alloparental responsiveness in common marmosets. Parentally naive adult common marmosets (Callithrix j. jacchus) were tested repeatedly for infant retrieval and carrying. Ten of the 14 marmosets retrieved by the fourth test and the four monkeys failing to retrieve never retrieved infants in ten tests. Serum prolactin concentration was significantly correlated with carrying time and was significantly elevated after infant-exposure only in the alloparentally responsive monkeys. Bromocriptine administration reduced serum prolactin to undetectable levels and was associated with significantly reduced frequency of infant retrieval and mean carrying time. We conclude that alloparental responsiveness is a stable trait after initial effects of novelty are overcome. High prolactin levels are important for alloparental responsiveness in common marmosets. (Parental Care 2; Sun. 2:15pm-2:30pm; NMM1)

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University of Washington (robinet@u.washington.edu)

The producer-scrounger model suggests that the number of producers (animals that search for food), and scroungers (animals that steal food found by producers) may be an Evolutionary Stable Strategy (ESS). In general, it has been difficult to test game theoretical models in the field. By following foraging decisions made by beach-foraging crows, individual stability in strategy use, variables influencing scrounging, and the benefits and costs of producing and scrounging were assessed. Data were collected on subject identification, search time, prey type, and the number of attempted and successful scrounges, group size, season, and prey density. Individuals were more likely to utilize both producing and scrounging strategies than to be "pure" producers. No pure scroungers were documented. When producers obtained scroungeable items (large items or those with long handling times), scroungers attempted to steal the item 46% of the time. Forty-one percent of those attempts were successful. Thus, producers suffered a 19% loss rate of scroungeable items to scroungers. A monte carlo simulation incorporating the probability of finding and stealing prey and the gross energy associated with each prey type revealed that the payoffs to producing and scrounging were equal, as you would expect if the population were at the ESS. (W.C. Allee Competition; Mon. 2:30pm-2:45pm; Sale)

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University of Kansas (rafa@falcon.cc.ukans.edu)

The evolution of female choice may involve co-evolution of male and female sexual traits and direct or indirect benefits for females. But sensory bias studies indicate that the female trait exerting selection on males may appear in a clade before the male trait and may be under selection in a different context. This apparent contradiction may stem from a confusion of levels of explanation. The solution requires correct contrasting of ultimate and proximate questions. At the ultimate level of explanation, if the male trait and the female preference do not co-evolve, there should be a correlation between selection responsible for the female sensory bias and selection exerted on the male trait. I tested this on wax moths, whose hearing evolved to detect bat echolocation but is also used in pair formation. Males produce ultrasonic calls that females prefer if they have a high signal rate. I obtained the minimum signal rates of male and bat calls to which females responded with phonotaxis or evasive flight maneuvers. Female responses were not correlated. Thus, co-evolution of the male trait and the female preference is possible. (Evolution of Signals; Tues. 9:45 AM - 10:00 AM; NMM1)

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Vassar College (chaos@vassar.edu)

Vocalizations were recorded from crows in the late winter and spring in five locations in eastern New York state. The classification of calls was adapted from Parr (1997). Comparisons were made both within species and between species, and included duration, intercall interval, harmonic interval, and highest frequency. There were differences among the flocks of American crows, suggesting dialects across the recording sites. The between species tests showed significant differences for all components measured. The greater repertoire for fish crows may be related to the fact that, in this part of New York state, they migrate while the American crow over winters. (Communication 2; Weds. 2:15pm-2:30pm; NMM1)

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University of Georgia (crosenga@arches.uga.edu)

Children use three strategies (pair, pot and subassembly) to combine objects into stable seriated structures. These techniques may differ in cognitive complexity; they emerge in sequence in the first years of life. The subassembly method (two cups are treated as one unit and placed together into another cup) is considered an example of hierarchical activity, and is associated with efficient seriation. Tufted capuchins (Cebus apella) use these methods. The purpose of the current study is to determine if experience in the task produces a shift towards greater use of the most efficient method of combining cups. Two capuchins were trained to combine objects into structures, using same-sized cups, without opportunity for learning about seriation. Both monkeys were tested in three phases in a task requiring the combination of variable-sized cups to construct a seriated structure. Phase one consisted of the monkeys first exposure to the variable-sized cups; phase two followed familiarization with the cups, and phase three occurred after each monkey had become an "expert" at creating structures. Both individuals increased subassembly usage and decreased their pairing as experience increased, suggesting that experience alone can replicate the changes in strategy selection that have been attributed to cognitive maturation in humans. (General Poster Session; Tues. evening; Archer Hall Gym)

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Cornell University (mgr4@cornell.edu)

Brooding behavior is a likely cue to a female’s reproductive status and therefore a potentially important factor in male mate assessment. Brooding behavior was induced in female quail by exposure to foster chicks for five, 20 minute trials over three days. Using a mate choice paradigm (White & Galef, 1999) we assessed the influence of this brooding behavior on male mate choice in Japanese quail. We gave males a choice between two females presented simultaneously and measured preference by the time spent in proximity to each. A male’s preference for the initially preferred female significantly decreased after he had seen her brooding three chicks. In the control condition, male preference for an initially preferred female remained relatively consistent over consecutive trials if he did not see her brood chicks. The present data suggest that females who are brooding chicks are less attractive to male Japanese quail. Further research will determine why males avoid such females. (Mate Choice 2; Sun. 2:45pm-3:00pm; NMM2)

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Arizona State University (r.rutowski@asu.edu)

Many physiological functions and mechanical properties of animal bodies that influence behavior vary with body size both within and between species. In this talk I will explore how eye structure might change with body size in arthropods, the implications of these changes for vision and for behavior. Data comparing the structure and optics of four species of butterflies that range from 17 to 80 mm in forewing length suggest that while visual field size changes little with body size, larger butterflies have both larger facets and smaller interommatidial angles. This suggests that trade-offs between facet size and interommatidial angles change with body size, and that acuity and sensitivity of vision increase with body size. I will discuss the implications of these effects of body size on vision for our understanding of the behavioral ecology of butterflies and other arthropods. (Communication 1; Weds. 10:30 AM - 10:45 AM; NMM1)

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Cornell University (rjs37@cornell.edu)

Perhaps the only commonality among group-breeding organisms is variation in colony size. I explore the possibility that colony-size variation persists as a result of individual dispersal tactics. I examine the breeding biology of social vertebrates to answer the following population-level questions. What is the distribution of colony-size variation in the population (e.g., bimodal)? What proportion of the population is solitary vs. group breeders? What are the costs and benefits of social vs. group breeding? Next, I examine individual-level patterns within popuations. Do attributes of individuals predict a preference of breeding site type (solitary vs. group)? What are the dispersal patterns of individuals within this population and how widely do they vary among first-year individuals? Is there a relationship between individual dispersal tactics and colony-size variation? Are dispersal patterns stable or do they change within an individual's lifetime as a breeder? In this review, dispersal tactics of individuals will be explored to explain results of the interaction between individual variation and social structure. I will discuss the emergent-properties of colony-size variation from the perspective of individual-based decisions.

(Dispersal Symposium; Sun. 3:45pm-4:15pm; Sale)

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Lehigh University (Ni55@lehigh.edu)

Very few mate choice studies are concerned with males of monogamous species. Our previous studies have shown that females prefer to spawn with larger males and show a continuous assessment of available individuals. How males distinguish between potential mates in the absence of female-female interactions was studied using convict cichlids (Archocentrus nigrofasciatum formerly Cichlasoma nigrofasciatum). Males were placed in tanks in which they had access to two individual females that did not have contact with each other (visual or tactile). Females varied in quality (size is correlated to quality in convict cichlids), and males had the opportunity to spawn with either of them. The male choice process will be discussed and compared to the female choice process. (Mate Choice 4; Weds. 10:45 AM - 11:00 AM; NMM2)

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San Francisco State University (pschick@sfsu.edu)

A group of black howler monkeys was studied over a three-month span during a dry season at Lamanai, Belize. The site served as a semi-forested corridor for two migrating howlers, and as a home for two human-reared juveniles. During this study, a daily activity pattern was determined for black howlers at Lamanai, as well as an analysis of the effects environmental variables have on habitat selection. The habitats which the howlers chose to occupy were broken down into five segments of different qualities. A greater percentage of time was spent in segment 5 (29.5%), a habitat of excellent quality with various fruiting and leafy trees of different heights. The activity budget of black howlers at Lamanai yielded percentages of 62.7% (rest), 17.0% (feed) and 15.0% (travel). These results were consistent with data observed at different sites with comparable habitat. Significant correlations were observed between the pair of migrating howlers with respect to resting, traveling, feeding and vocalization. Howlers show a significant preference for certain habitats based on our findings. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of New Hampshire (suzanne@cisunix.unh.edu)

The lobster population of the Great Bay estuary system exhibits a skewed sex ratio of adults, with as many as 5 times more males than females in the upper reaches of the estuary (Howell et al., 1999). Our work examines the role of temperature in the development of this distribution pattern. Previous research (Crossin et al., 1998) shows that female lobsters have a lower preferred temperature and are more likely to exhibit avoidance responses than males when held at summer ambient temperatures (15-17ºC). However, in the same study, neither male nor female lobsters held at winter ambient temperatures (2-4ºC)were observed to exhibit any avoidance response when exposed to the same relative temperature increase (~8ºC) as summer lobsters. Our goals were to determine if lobsters held at winter ambient temperatures would exhibit an avoidance response at the same absolute temperature as lobster held at summer ambient temperatures and if sex based differences would persist in winter conditions. Preliminary results indicate that lobsters held at ambient winter temperatures do exhibit an avoidance response, although at a lower average temperature than that which elicits an avoidance response in lobsters held at summer ambient temperatures. Further work will be necessary to elucidate sex-based differences. (Habitat Choice; Mon. 5:00pm-5:15pm; Sale)

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Bowling Green State University (schroed@caspar.bgsu.edu)

Size-matched pairs of crayfish readily engage in agonistic encounters. Interactions increase in intensity until one individual withdraws. In such escalating fights the risk of injury rises as individuals begin to make unrestrained use of their potentially lethal weaponry. The growth of the claws greatly outpaces that of the rest of the body during normal development, and weapons should thus play a disproportionately greater role in fights between larger individuals compared to smaller ones. To examine this hypothesis, we analyzed the fight characteristics and fighting strategies in small size-matched pairs of crayfish having an average weight of 1.8 grams and large size-matched pairs of crayfish weighing an average of 17.9 grams. Specifically, this study compared the number of interactions, their duration, maximum intensity, and rate of escalation between fights of the small and large groups of crayfish in an experimental arena scaled to the size of the animals. Fighting in small pairs was characterized by more interactions of shorter duration than between larger individuals. In agreement with our model, small crayfish escalated fights more quickly than larger individuals. (General Poster Session; Tues. evening; Archer Hall Gym)

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Georgia Southern University (BAS) (bschulte@gasou.edu)

The captive elephant population in North America is in reproductive decline and without importation from the wild may cease to be viable within decades. The estrous cycle of three captive, reproductive age African elephants was monitored for three years by measuring serum progesterone concentrations. Each elephant experienced one or more episodes of extended low progesterone (>12 weeks), indicating a temporary period of ovarian inactivity or acyclicity. Reports of similar bouts of acyclicity exist; however, this phenomenon has not been examined in detail. In this study, the most subordinate female had the longest and the dominant female had the shortest total duration of acyclicity. During periods of acyclicity, the number of hours the elephants spent outside was significantly less than during non-luteal or luteal phases. Except in one instance, behavioral data recorded by elephant keepers during their interactions with the elephants showed no change in handling during periods of ovarian inactivity. Further study is necessary to distinguish the cause for acyclicity. Understanding this phenomenon is imperative for the future reproductive viability of captive elephant populations and will shed light on reproductive mechanisms that may operate in wild elephants. (General Poster Session; Tues. evening; Archer Hall Gym)

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Instituto de Ecologia, A.C. & Instituto de Biologia, UNAM (biojserv@jinx.umsl.edu)

The movements of coyotes (/Canis latrans/) were studied for two years (1990-1991) in a oak-pine forest area between 2,200 to 2,700 m above sea level in Southeastern Durango, Mexico. Fifteen adult coyotes (7 females and 8 males) were trapped, radiocollared and radiotellemetry data were obtained using 24-hours samples. Data were grouped into four biological seasons (breeding, gestation, pup rearing and juvenile independence). High travel activity was found; males travelled longer distances (16.47 km) than females (12.51 km) in 24-hours periods (p<0.001). Annual mean night travel distances were longer (8.24 km) than day movements (6.51 km) (p=0.0206). Females and males travelled similar day and night mean distances in breeding, gestation and juvenile independence seasons. However, during the pup rearing season males (p=0.004) and females (p=0.025) were active preferentially at night. Locomotor activity is influenced by biological seasons, food availability in time and space, as well as individual characteristics. The daily travel distances of coyotes reflect their constant interaction with the environment; food abundance and biological seasons determine daily extent of movements. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Northern Colorado (hall5684@blue.unco.edu)

We tested spatial learning abilities of steppe ferrets (Mustela eversmanni) in bright and dim moonlight. Steppe ferrets live in a relatively featureless habitat, the Siberian steppe, and often travel long distances; thus, identifying distant visual landmarks is likely important. Spatial learning trials were conducted in a hexagonal arena with 19 evenly spaced holes (18 blind-ended, 1 goal). No visual or scent cues were available within the arena. Neutral spatial cues were visible outside the arena on the ceiling and walls of the room. Trials were conducted in simulated half moonlight (0.35 lux) and then in simulated quarter moonlight (0.15 lux). In successive half moonlight trials, time to find the goal and distance traveled decreased (P<0.05). In successive quarter moonlight trials, time to find the goal and distance traveled were random. Although the number of times ferrets looked up at spatial cues did not differ in half moonlight versus quarter moonlight, ferrets looked up more in the first trial compared to later trials (P<0.05). These results illustrated ferrets used spatial cues to learn the goal location and ferrets had difficulty learning the goal location in dim moonlight. Spatial learning may be important to these nocturnal predators and to their close relative, the endangered black-footed ferret (M. nigripes). (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Western Ontario (sherry@julian.uwo.ca)

Menopause, the cessation of ovulation by women at about age 50, is an evolutionary puzzle. If the expected life span exceeds 50 years, what adaptive or non-adaptive processes could result in a reproductive life span shorter than the total life span? Proposed explanations have included a recent increase in human life span, senescent decline in reproductive function in women, and inclusive fitness benefits of parental or grand-parental care by post-menopausal women. We collected data from published sources on life span, reproductive life span, gestation length, age at weaning, age at sexual maturity, inter-birth interval, lifetime number of offspring, the presence or absence of descendant kin in the social group, and other variables for 30 species of primates, about 14% of all living species. Comparative analysis by independent contrasts showed the expected relation between body weight and life span, but revealed no relation between the post-reproductive life span of female primates and other life history variables examined. This result suggests that the post-reproductive life span does not vary directly with the duration of parental care or the age at sexual maturity of offspring, and is not explained by the presence of potential recipients of inclusive fitness benefits. (General Poster Session; Tues. evening; Archer Hall Gym)

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Northern Arizona University (stephen.shuster@nau.edu)

Males are more successful at monopolizing mates when females aggregate than when females are spatially dispersed. Thus, sexual selection is expected to be more intense in species in which breeding females form groups than in species in which breeding females are solitary. Multiple reproductive episodes increase the variance in fitness among females. Thus, sexual selection is expected to be less intense in species in which females produce several broods than in species in which females breed once. To test these hypotheses, I examined the effects of breeding site location and female life history on patterns of sexual size dimorphism and male combat structures in 31 genera of sphaeromatid isopods. Classification of genera was possible because females in infaunal genera are more spatially clumped than females in epifaunal genera. Also, females in genera that breed more than once possess intact mouthparts, whereas females in genera that breed once possess atrophied mouthparts. Males in all infaunal, semelparous genera were larger than females and possessed combat structures. Males in all epifaunal, iteroparous genera were the same size or smaller than females and tended to lack armament. In sphaeromatid isopods, the location and number of female reproductive episodes appear to influence the opportunity for sexual selection. (Sexual Selection; Sun. 4:15pm-4:30pm; NMM2)

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University of Education and Agricultural University, Iceland (hrefnas@khi.is)

To work out dominance relationships within a group of hoses, ad. lib. records were made of interactions between 15 individuals and experiments with grass pellets were carried out. Nearest neighbor analyses was also done. Behavior of individuals was scanned to get an estimate of timebudgets. The group was regularly split and kept in 3 differently sized enclosures. The relation between each pair of horses was based on both aggressive and submissive acts. The dominance rank was not fully linear. There was a significant positive relation between rank and weight and rank and aggressiveness. Most time was spent grazing and standing still. There was a significant positive relationship between weight change of individuals and size of available grazing area. Those horses which were of similar rank tended to stay together and have friendly relations. The 3 most dominant horses spent less time grazing than the others – a finding that suggests that these individuals were either dominating the best parts of the field or more efficient in feeding. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Kentucky (ndc@pop.uky.edu)

Although individual animals typically experience multiple environments in sequence (over space or time), relatively few studies have focused on how individual variations in behavior and performance carry over across environments. Are some individuals more active than others across different situations? If so, what effects do these behavioral carryovers have on performance (mating success, survival, feeding rate) in each situation? If, for example, high activity is favored in one situation, but low activity is favored in another, then a behavioral carryover across situations should produce a tradeoff across situations that reduces variance in overall performance. Alternatively, if high activity is favored in both situations, then an activity carryover should tend to make the same individuals do well in both situations; this increases variance in overall performance. We suggest new methods for analyzing effects of behavioral carryovers on fitness, and discuss some important implications of behavioral carryovers for the evolution of adaptive and not-so-adaptive behavior. We illustrate these ideas with data on feeding/antipredator behavior of larval salamanders, and on mating behavior of stream water striders. (Behavioral Context; Mon. 11:00 AM - 11:15 AM; NMM2)

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Murray State University & McGill University (paul.sikkel@murraystate.edu)

In many reef fishes, both sexes defend permanent territories, but spawning occurs in male territories alone. Thus, to spawn, females must leave their territories unguarded. In about 60% of cases, female yellowtail damselfish(Microspathodon chrysurus) complete spawning during a single trip. In the rest, spawning takes 2-20 trips. We tested one assumption and three predictions of the hypothesis that this variation reflects an adaptive response to the tradeoff between conspecific intrusion and travel cost. The impact of intruders (food loss and adult-eviction costs) increased exponentially with time. When fish that made multiple trips were experimentally prevented from doing so, intrusion rates increased significantly relative to controls. Females that made multiple trips had higher intrusion rates and spawned closer than did females that made single trips. However, among multiple-trip fish, neither intrusion pressure nor spawning distance correlated with trip number. These results suggest that fish are sensitive to intruder-pressure and/or travel costs, and that spawning in multiple bouts reduces intrusion costs. (Sexual Selection; Sun. 5:15pm-5:30pm; NMM2)

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Duke University (vbs@acpub.duke.edu)

Communicating to mates or rivals often increases the visibility of the signaler to predators. The repertoires of many species contain a variety of communication signals that may differ in their visibility to predators. In this study, I examine the influence of predation intensity on the use of individual signals in Anolis lizards. These lizards communicate with three major signals: the headbob, pushup, and extensions of the dewlap, a brightly colored throatfan. Using robotic lizards, I test the hypothesis that the dewlap extension is the most conspicuous signal to predators, then relate these results to observations of population-level differences in signal use. Variation in body condition and/or color patterns may also underlie individual and population-level differences in signaling behavior. Ultimately, the extent to which an individual's signal use is impacted by predation depends upon both the visibility of the signaler and the signaler's ability to escape predators. (Communication 2; Weds. 2:30pm-2:45pm; NMM1)

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University of Mississippi (Csims@olemiss.edu)

It has long been known that the corticosterone stress response in birds aids them in the avoindance of stressful perturbations. In this study I asked the question, is the stress response present or even necessary in young birds that are still dependent on parental care? In the summer of 1998 and 1999 blood samples were taken from seven age classes of Northern Mockingbirds (Mimus polyglottos) to measure the corticosterone stress response. Young birds (nestlings) were found to have a significantly reduced stress response when compared to independent juveniles and adults. This response increased in magnitude as birds gained independence from the parents. Subsequent injections with adrenocorticotropic hormone (ACTH) showed that nestlings lacking a stress response were not secreting ACTH from the pituitary, and that nestlings did have the adrenal capacity to respond to stress in their environment. Increases in baseline corticosterone concentrations from 6 days post hatch until the individuals fledged from the nest suggests a role for this hormone in facilitating energetic demands involved with this behavior of independence. (W.C. Allee Competition; Mon. 2:45pm-3:00pm; Sale)

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San Francisco State University (cds@sfsu.edu)

Great gerbils Rhombomys opimus of central Asian deserts exhibit alarm behavior that parallels both ground squirrel vocalizations and kangaroo rat footdrumming. In order to explore what information is conveyed by alarm calls, we tested the hypotheses that responses to alarm calls change depending on stimulus (different predators) and differ based on caller and respondent age and sex. We observed responses to a monitor lizard Varanus griseus or a domestic dog in ten minute tests, in ten family groups. It appeared that the different response patterns did not depend on the predator, although there were more alert postures in the lizard tests. 55% of the 151 alarm calls were issued with no other gerbils visible. 48% of the animals present to respond did not, while 35% responded by assuming a frozen alert posture. More than the alarm call may be required to understand what is being conveyed. We will further analyze layers within the experimental data, as well as responses to over one thousand calls studied during baseline observations. (General Poster Session; Tues. evening; Archer Hall Gym)

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The United States is in the midst of a scientific crisis in its high schools. Students are becoming disinterested in traditional biology, chemistry, and physics classes. Because of this it is important for educators to find an engaging alternative that reawakens student interest in science. Animal Behavior could serve this need because through the study of animals students can learn many basic biological and chemical topics. The purpose of this high school level curriculum is to excite students with a study of animal behavior, and therefore science in general. This elective course was created to engage students in classroom, laboratory, and fieldwork with a hands on emphasis. Students study classic and modern Animal Behavior experiments as well as a variety of behavioral topics and ideas. Interaction with college professors and a study of scientific journal articles is essential to the development of student projects. Students learn about the scientific method through designing and performing their own experiments. In addition, students learn how to prepare a paper for publication as well as do 15-min. oral presentations similar to those seen at scientific meetings. Initial response has been good though sample size is relatively small. (General Poster Session; Tues. evening; Archer Hall Gym)

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Indiana University (vismith@indiana.edu)

The social environments surrounding juvenile cowbirds (Molothrus ater) can affect vocal and social development. This study was designed to determine whether a group of cowbirds produces a recognizable social organization, and how the overwinter social environment of juveniles relates to behaviors such as singing and courtship. Seventy-four cowbirds of four age and sex classes, adult and juvenile males and females, were allowed to assort freely throughout a large outdoor complex of connected aviaries. We measured overwinter associations and singing behavior, then spring courtship success. The birds did not assort randomly; there was a clear social structure. All four classes associated with other individuals based on decreasing similarity in age and sex. Juvenile males who associated less with females sang more. Juvenile males who associated more with adult males had higher courtship success. These results indicate that a captive group of cowbirds produces a self-organized social structure based on age and sex. The social environments created by this structure correlate with individual differences in communication and courtship. (Social Behavior 1; Mon. 5:00pm-5:15pm; NMM2)

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University of Wisconsin (snowdon@facstaff.wisc.edu)

Cotton-top tamarins are cooperatively breeding monkeys where fathers and non-reproductive helpers carry infants and share food with infants at the time of weaning. The high degree of cooperative behavior suggested a possible social transmission about food quality. We presented 10 family groups with a highly preferred food (tuna fish) adulterated invisibly with white pepper. An equally preferred food that was not adulterated was presented as a control. Both foods were presented weekly for three weeks and subsequently the tuna was presented weekly without pepper. In groups only 25% of animals ever sampled the adulterated tuna, the others avoiding even tasting tuna. Once an animal sampled the peppered tuna it rarely sampled it on subsequent weeks. Some groups stopped eating tuna for more than 15 weeks after normal tuna was restored. Tamarins greatly reduced food sharing of peppered tuna with infants. Visual signals of disgust were the primary means of communication. Social communication about unpalatable food allowed other group members to avoid even sampling the food. Social communication may be particularly effective in cooperatively-breeding species. Supported by USPHS Grant MH 29775. (Communication 1; Weds. 11:15 AM - 11:30 AM; NMM1)

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Giant panda sociosexual development is unusual because pandas are a solitary species and cubs are usually raised in the absence of siblings. Thus for giant pandas, the role of the mother in the socialization of her offspring may be especially important. There is evidence that the opportunity to engage in contact behaviors with conspecifics, particularly social play, is necessary for normal behavioral development in mammals. This makes the issue of play particularly relevant for species, such as the giant panda, that do not reproduce well in captivity. This study examined social play between captive giant panda mothers (N = 3) and cubs (N = 4). Mothers spent large portions of time engaged in reciprocal rough-and-tumble play with their cubs, and frequently initiated bouts of social play. Male cubs spent more time engaged in social play with their mothers than did a female cub. Correspondingly, male cubs initiated play bouts with their mothers more frequently than did a female cub. The results of this study contribute to a better understanding of the behavioral process of giant panda development and particularly the role the mother plays in socialization of the cub. (Parental Care 2; Sun. 3:00pm-3:15pm; NMM1)

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Universidad Nacional Autonoma de Mexico (vsolar@miranda.ecologia.unam.mx)

Food avaibility is expected to modify the patterns of parental care and thus the timing of desertion . In the magnificent frigatebird (Fregata magnificens) males desert their chick early leaving the females to raise the offspring unaided. Under reduced food availability males are expected to desert later than in localities or years of plenty. The "El Niño" climatic event reduces food availability in the Pacific colony at Isla Isabel, and we tested whether such food deficit delayed desertion in 1998 compared to desertion in colony at an Atlantic island at the same latitude (Isla Contoy). We found that in the Pacific males deserted latter and contributed longer to chick feeding, but chicks grew faster and fledged earlier in the Atlantic. This suggests that male frigatebirds facing a short food supply may increase their parental investment by delaying their desertion in order to increase their offspring's survival. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of New Hampshire & Smithsonian National Zoo (msommer@hopper.unh.edu)

Over several decades South American fur seal (Arctocephalus australis) populations at Punta San Juan, Peru have declined dramatically and seals have abandoned some breeding sites. Little research has investigated what factors might influence abandonment of sites. We examined how habitat features and disturbance (humans and sea lions) affected whether areas were currently used (n=6), abandoned (n=5), or apparently not used in the past (never; n=6). Binary recursive partitioning analysis revealed that presence of shade classified areas as 'currently used' vs. 'formerly or never used' (correctly classified 100% and 73% of cases respectfully). Discriminant analysis correctly classified 100% of cases. Abandoned areas were more likely to be disturbed by humans and sea lions, and had greater slopes at the landward side than currently used areas. Areas never used were more likely to have sand or gravel shores, no sea spray and no disturbance by sea lions. A. australis apparently consider thermoregulatory needs and the potential for sea lion disturbance in selecting and maintaining breeding areas. Habitat features associated with thermoregulation may be more important to fur seals in Peru, which breed at lower latitudes and are at greater risk of overheating on land, than other populations in South America. (Habitat Choice; Mon. 5:30pm-5:45pm; Sale)

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University of California - Davis (trspoon@ucdavis.edu)

The strictest definitions of mating systems rely solely on the number of individuals with which males and females mate, but in practice, observed association patterns between males and females are the most salient aspects of a mating system. Indeed, in socially monogamous species with biparental care, reproductive success may depend on the quality of the relationship between pairmates. This study examines the reproductive consequences of variation in pair relationships in cockatiels (Nymphicus hollandicus), a socially monogamous species with biparental care. Unpaired, adult cockatiels were housed in a social environment and allowed to form pairs, mate, and rear chicks. To avoid confounding social and mating aspects of pair behavior, behavioral observations prior to the initiation of breeding provided data on pair relationships. Several measures of pair behavior were related to parental care and extra-pair relationships. Pairs characterized by closer proximity, lower aggression, and greater synchrony of behaviors exhibited greater coordination of incubation, higher hatching success, and lower frequency of extra-pair courtship by males. (Mate Choice 3; Mon. 3:00pm-3:15pm; NMM1)

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Miami University (spritzmd@muohio.edu)

Most species cache food to gain direct benefits from consuming caches, but some species gain indirect benefits by caching communally with kin. I investigated whether gray squirrels cache communally or selfishly. I predicted that if squirrels cache communally with kin, then genetically related squirrels should cache near one another to facilitate cache sharing. In contrast, if squirrels behave selfishly, they should clump their caches near the center of their ranges to facilitate cache defense. This study was conducted with 140 squirrels in a forest on the University of Florida campus. DNA was extracted from blood samples, and band matching scores for RAPD loci were used as an index of relatedness. Squirrels were given piles of pecans at six sites and observed from a blind. At one site, squirrels were observed taking pecans wrapped with aluminum foil, and a metal detector was used to locate caches. The direction squirrels were observed taking nuts from piles was obtained at the five other sites. The relatedness of neighboring squirrels did not influence caching location or direction. Squirrels clumped their own caches and moved nuts toward their own range centers. These results suggest that gray squirrels engage in selfish caching. (Social Behavior 1; Mon. 3:45pm-4:00pm; NMM2)

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Ball State University (00tmsproat@bsu.edu)

Defending eggs and young against potential predators can be an important component of parental investment in birds. This study investigated how a defender's sex or the male's mating strategy affected house wren (Troglodytes aedon) nest defense behavior. Experimental trials presented stuffed eastern bluebird, brown-headed cowbird, and house wren models to house wren nests. Levels of "active" and "passive" defense behaviors and wren vocalizations were recorded for each trial. Results showed that males took a greater role than females in defense against the house wren. However, females showed slightly more "passive" defense behaviors than males against the bluebird. Males attentive to their primary nest showed more "active" behaviors toward the house wren and cowbird, than non-attentive males. Females showed no differences in defense levels based on their mate's breeding strategy. Male house wrens may exhibit greater defense levels as an extension of their intraspecific territory defense role. Female house wrens may show lower defense levels, and use more "passive" behaviors, as a result of higher perceived risk. Non-attentive males appear to sacrifice defense of existing young for opportunities to increase their fecundity. (Parental Care 1; Sun. 11:30 AM - 11:45 AM; NMM1)

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University of California - Davis (jastamps@ucdavis.edu)

Behavioral research is shedding new light on the complex relationships between the proximate mechanisms involved in habitat selection and the selective pressures that may have contributed to the evolution of those mechanisms. Habitat selection by dispersers can be divided into three stages (search, settlement and residency); recent studies suggest that the fitness consequences of behavior at each of these stages often differs from the assumptions made by traditional habitat selection theory. For instance, dispersers may benefit from the presence of conspecifics or heterospecifics while searching for, settling in, or living in new habitats, and individuals may prefer to settle in post-dispersal habitats that are similar to their pre-dispersal habitats, because this behavior reduces the costs of detecting or assessing suitable habitats (habitat cuing) or because experience in a particular type of pre-dispersal habitat improves performance if an individual selects the same type of habitat after dispersing (habitat training). Animals have evolved a variety of proximate behavioral mechanisms to reduce search and settlement costs when moving through natural environments, and since many of these mechanisms operate during dispersal, understanding habitat selection may improve the ability of conservationists to predict and manipulate the behavior of dispersing individuals. (Dispersal Symposium; Sun. 4:15pm-4:45pm; Sale)

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Davidson College (mastanback@davidson.edu)

By nesting in cavities low to the ground, secondary cavity nesters increase the likelihood of detection by mammalian and reptilian predators. By reusing soiled nests, such birds incur the costs of nest ectoparasites. By experimentally varying these two factors, we tested the relative importance of each to nest site fidelity in Eastern Bluebirds (Sialia sialis). Choice experiments demonstrated that bluebirds avoid reusing soiled boxes (if also given a clean box) but prefer to reuse successful nest boxes (if they are clean). Bluebirds also showed a significant preference for high (2 m) vs. low (1.7 m) boxes for their first nests of the year, suggesting sensitivity to predation risk. For second nests, we forced bluebirds to choose between their successful soiled high box and a clean low box. Bluebirds reused soiled high boxes significantly more often than they used clean low boxes and significantly more often than they reused soiled cavities when given boxes of equal height. Thus under these conditions, bluebirds are willing to incur the costs of parasitism in order to lessen susceptibility to predators. (Habitat Choice; Mon. 4:00pm-4:15pm; Sale)

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University of Wisconsin - Milwaukee (mstap@csd.uwm.edu)

It is often assumed in studies of female mate choice that female preferences for certain male traits are repeatable. For example, many studies of extra-pair mate choice suggest that females are choosing extra-pair mates for their superior genotypes. Sexual selection will favor these genotypes only if females are consistent in their choice of extra-pair sires. Tree Swallows have the highest level of extra-pair mating among North American birds. I tested whether female Tree Swallows are consistent in their choice of within-pair and extra-pair males within a single breeding season by experimentally forcing females to lay a second clutch and, thus, choose to remate with the same or different males. Sires of young in the first and replacement broods were identified using parentage analysis based on microsatellite DNA. We discuss our results in relation to the assumption that female birds consistently choose males to improve the genetic quality of their offspring. (Mate Choice 4; Weds. 9:30 AM - 9:45 AM; NMM2)

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Bowling Green State University (lobsterman@caspar.bgsu.edu)

Crayfish chelae are dangerous weapons employed in fights among conspecifics. Individuals reduce the associated risks of combat by assessing each others fighting abilities in a step-wise fashion. This is achieved through a slow escalation of intensities using a sequence of stereotyped behavior patterns. Resorting to the rapid use of claws and unrestrained combat without prior assessment of the opponent's fighting ability thus carries great hazards. Hungry animals may take greater risks to obtain food. Similarly, individuals may be more daring when a desired resource is actually present in the surrounding. The goal of this study was to test these hypotheses by explore differences in fighting strategies between hungry and satiated individuals in the presence or absence of a chemical food cue. Individual decisions for initiating encounters, escalating to higher intensities, retaliating, or finally retreating from an interaction, were compared within a 2x2 factorial design. In agreement with our hypotheses, hungry crayfish escalated more rapidly than satiated individuals. Our discussion focuses on the complex trade-offs between increased risks of injury, appetitive states, and increased opportunities for resource access. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of California, Auburn University & Cornell University (amstoehr@citrus.ucr.edu)

We investigated the effects of nestling mites on the health of house finch nestlings and on the response of parents to determine if this parasite might contribute to sexual selection in this bird. Although the mites did not affect nestling tarsus length, they significantly reduced nestling hematocrit and mass. Despite the negative effects of mites on nestlings there was no relationship between nest mite levels and male plumage color as one might predict if male plumage color serves as a signal of parasite resistance. Furthermore, neither male nor female house finches responded to increased mite levels with increased nestling feeding rates. However, the onset of mite infestation in our population is sudden and predictable, and redder male birds begin nesting earlier in the breeding season. Thus, avoidance of high mite loads through early nesting may contribute to sexual selection for bright male plumage in the house finch. (Immune Systems & Behavior; Weds. 2:15pm-2:30pm; NMM2)

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Georgia Institute of Technology, Zoo Atlanta, National Zoo (stoinskit@mindspring.com)

While many reintroduction programs collect data on survival rates, knowledge about the behavioral development of captive-born, reintroduced animals and their offspring born in the wild is basically non-existent. This study examined the behavior of first- and second-generation descendents N=67. of captive-born, reintroduced golden lion tamarins. First generation animals were also divided into two cohorts: 1. the first set of offspring born to captive-born, reintroduced animals, and 2. all other sets of offspring born to captive-born individuals. Significant differences in height off the ground, substrate use, and foraging behavior were found between the generations and between the cohorts of the first generation. There were few significant differences between the second-generation animals and the second cohort of the first generation. These results suggest that behavioral adaptations of reintroduced tamarins may occur over more than one generation. Additionally, behavioral adaptation may occur more quickly when individuals are exposed to wild-born conspecifics than when individuals are exposed only to captive-born individuals. (Conservation; Weds. 10:00 AM - 10:15 AM; Sale)

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Texas Tech University & University of Tennessee (chiggins@ttacs.ttu.edu)

The analysis of search paths plays a key role in optimal foraging theory. We developed a simplified model of resource acquisition in which we randomly dispersed N points ("food items") of equal value within an arena, and we only considered the search path followed to find and consume the N items (assuming no satiation or learning). For a given point configuration, two deterministic models, the globally optimal shortest and longest paths (the former corresponding to the search of an omniscient predator) provide the lower and upper bounds on path length. We characterized the lengths and shapes of search paths produced under five probabilistic and two other deterministic models: random choice, Pearson random walk, Levy random walk, reciprocal-distance preference, inverse-squared-distance preference, trajectory-directed search, and nearest neighbor. Each resulting search path was characterized geometrically by its total length, distribution of step lengths, vector autocorrelation function, distribution of angular deviations, and number and spacing of path intersections. In addition, we used canonical variate analysis to discriminate paths produced by the different models based on these path descriptors. This basic procedure can be extended in various ways and can potentially be used to classify observed search patterns of predators according to underlying foraging models. (Foraging; Tues. 2:15pm-2:30pm; NMM2)

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York University & St. Mary's College of Maryland (BStutch@yorku.ca)

Males of many avian species make extra-territory forays to neighboring territories to seek copulations with extra-pair females. We quantified male EPC effort in Hooded Warblers (Wilsonia citrina) using radiotelemetry to determine if male foray behavior correlates with fertilization success. Females control EPCs in this species, in that they make forays of their own as well as 'chipping' on territory to attract neighbor males. About 30% of the young are the result of extra-pair fertilizations. We predicted that (1) males with a high foray rate will not suffer high cuckoldry themselves because they are high quality males whose mates remain faithful despite the frequent absences of their male, and (2) greater foray effort results in higher EPF success. An alternative hypothesis is that forays are a best-of-a bad strategy performed primarily by low quality males, in which case foray rate would not correlate with EPF success and males with high foray effort are often cuckolded. We also compared the foray effort and EPF success of males in continuous forest who have many close neighbors versus males who occupy territories in isolated forest fragments. Males in fragments traveled much greater distances, and for longer periods, often over open fields to visit neighboring females. (Mating & Reproductive Success; Mon. 3:45pm-4:00pm; NMM1)

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York University (bstutch@yorku.ca)

Our understanding of how individuals go about acquiring a breeding territory is still meager compared with our knowledge of territory defense itself. A variety of experimental tools have been used to reveal complex dispersal tactics. The first such tool was the shotgun, where simultaneous removal of territory owners of many different species from a temperate forest resulted in replacements occupying the territories. Banding studies of a resident tropical bird revealed an 'underworld' of non-territorial birds who defended areas that encompassed several breeding territories. When territory owners disappeared, the replacement was the non-breeder who had controlled that area. Direct observations of floaters in swallows showed that nonbreeders wandered widely ('floating') to probe for vacancies, but in martins nonbreeders focused most of their intrusion effort on a few territories to literally wear down the owner's defense. Temporary removal of territory owners has been used widely to stage contests for breeding vacancies, revealing that non-breeders compete more intensely for high quality breeding positions. These experiments naturally lead to the question of why dispersal tactics vary among species, and among individuals within a species. (Dispersal Symposium; Sun. 10:45 AM - 11:15 AM; Sale)

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Seoul National University (rhodeus@hotmail.com)

Males of common freshwater gobies, Rhinogobius brunneus, which provide paternal care, are larger in body size, and have the first dorsal fin (FDF) that is markedly longer and more elaborate in color and shape than females. Previous studies of fish with paternal care have demonstrated the importance of male body size and nest size in female mate choice. In our laboratory tests, females showed a strong preference for males with longer FDFs, but mated randomly with respect to male body size or nest size. The strength of preference for the longer FDF increased with inter-male difference in the FDF length. Males with longer FDFs had no advantage in male-male competition, while the outcomes of male fight were determined largely by body size. Our tests suggest that female choice and male-male competition may affect the evolution of different male morphological traits in R. brunneus. Intersexual selection may be responsible for the evolution of the elaborate FDF, while intrasexual selection may have selected for increased male body size. (Mate Choice 4; Weds. 11:30 AM - 11:45 AM; NMM2)

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Utah State University (yejunco@cc.usu.edu)

In Arizona, Yellow-eyed Juncos are altitudinal migrants and show site fidelity within breeding seasons, between breeding seasons and in natal dispersal. There are no significant differences in dispersal distances between male and female Yellow-eyed Juncos. Distance between nests within a breeding season averaged 55m (SE = 5, 108 pairs). Distance between the last nest of one season and the first nest of another averaged 85.6 m (SE = 10, 58 males) for males and 117 m (SE = 13, 63 females) for females. Distance dispersed from natal nest to first nest as a breeding adult averaged 342 m (21 females) and 512 m (23 males) for males. The factors associated with individual variation in dispersal distances will be presented. (Dispersal; Sun. 5:15pm-5:30pm; Sale)

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Zoological Society of San Diego (rswaisgood@sandiegozoo.org)

We tested the efficacy of an enrichment program for giant pandas at the Wolong Breeding Center in China. Pandas spent significantly more time active, and displayed a greater variety of object- and non-object-directed behaviors when enrichment was present. There was also a significant reduction in stereotypic behavior and behaviors indicative of feeding anticipation. This effect was maintained even when pandas were not interacting directly with enrichment, suggesting that enrichment had a motivational carry-over effect in the aftermath of interactions with enrichment items. These results are consistent with the ethological needs model of motivation in that opportunities to perform more natural behavior appeared to improve motivational indices of well-being. Age proved to be an important determinant of responsiveness; for example, adults, but not subadults, displayed a significant preference for feeding enrichment. Although all five enrichment items were equivalent in their ability to increase or reduce behavioral measures relating to well-being, each item promoted a distinct behavioral profile. The types of behavior observed are readily mapped onto the specific attributes of the enrichment item. (Conservation; Weds. 9:30 AM - 9:45 AM; Sale)

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Michigan State University (szykmanm@msu.edu)

Although female mammals tend to be choosier than males with respect to their mate preferences, theory predicts that males should also be selective when female fecundity varies. Reproductive success varies profoundly with social rank among female spotted hyenas. Our goals here were therefore to determine whether male hyenas preferentially associated with high-ranking females, and whether male preferences were affected by female reproductive state. Interactions between adult males and females were observed intensively, and association indices were calculated for all male-female pairs during a 7-year period in one population of free-living hyenas. Males initiated most affiliative interactions with females, and males associated most closely with females that were likeliest to be fertile. High- and middle-ranked males associated most closely with high-ranked females, and low-ranked males with middle-ranked females, suggesting that low-ranked males adopt a different reproductive strategy. Males identified as fathers of cubs born into the clan associated more closely with the mothers of those cubs than did non-fathers, particularly during the last months before conception. These association data indicate that male spotted hyenas prefer females likeliest to maximize male reproductive success. (Mate Choice 4; Weds. 11:00 AM - 11:15 AM; NMM2)

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University of Maine (becky.talyn@umit.maine.edu)

Females often use courtship signals to determine the species and the quality of potential mates. Drosophila melanogaster use complex courtship behavior, several components of which are known to contribute to reproductive isolation from sibling species. The goal of this study is to extend our understanding of acoustic courtship signals to include those used for intraspecific sexual selection. Acoustic signals that are energetically expensive to produce are expected to elicit higher levels of mating. Artificial songs were generated to resemble songs recorded from males, and with individual song parameters altered. These songs were played to groups of males and females, and both courtship and mating observed. While male courtship behavior differed little between song treatments, more mating occurred when songs contained more of one song component, pulse song. Since songs containing more pulse song require more energy to produce, only higher quality males should be able to produce them. Surprisingly, the other song component, sine song, did not influence the amount of mating in any of several experiments. We hypothesize that sining behavior is maintained by inextricable association with another signal. (W.C. Allee Competition; Mon. 3:00pm-3:15pm; Sale)

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University of Missouri (zuleyma@umsl.edu)

The habituation-discrimination paradigm has been used for many years to demonstrate individual discrimination by odors and, more recently, to study kinship odors. Two different methods (Halpin; Johnston) based on the same rationale, have been assumed to be directly comparable. Using Johnston's method, Todrank et al. (1998) found that golden hamsters cannot discriminate between the odors of two siblings that are unrelated and unfamiliar to the subject. In contrast, in 1999, using Halpin's method, we found that prairie voles, Microtus ochrogaster, are able to discriminate between such odors. We hypothesized that these contradictory results could be due to differences in species or in methodology. We have now conducted additional studies on voles using both methods. With the Halpin method our initial results were confirmed. However, using Johnston's methodology, we found no evidence of discrimination between the odors of brothers. This suggests that the two methods are not always comparable. Key factors may be the strength of habituation, the possibility that social preferences can influence the results, and species differences. (Recognition & Mate Choice; Tues. 2:00pm-2:15pm; NMM1)

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Georgia Tech University (gt4636a@prism.gatech.edu)

Many zoos have begun to use surrogate mothers to facilitate the integration of hand-reared infants into a social group. Early integration into a normal social group may promote normal social development and minimize the development of abnormal behaviors that are often observed in hand-reared infants. Until now, there have been no long-term studies comparing the behavioral development of surrogate-reared and mother-reared infants. Data were collected twice a week on a variety of solitary and social behaviors in one surrogate/infant and two mother/infant pairs. From 3-12 months of age, there were no differences between surrogate-reared and mother-reared infants in time spent in contact with, proximate to, or distant from their mothers. Nor were there differences between infants in levels of self-manipulation, object manipulation, solitary play and social play. From 13-18 months, the surrogate infant spent more time in contact with the surrogate, less time far distant from the surrogate, more time social examining group members, more time engaged in social play, and less time engaged in object-oriented behavior and solitary play. The surrogate infant showed no signs of abnormal behavior. These results suggest that surrogate-rearing may be effective in fostering normal social development and discouraging the development of abnormal behaviors. (Parental Care 2; Sun. 2:45pm-3:00pm; NMM1)

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University of Cincinnati, Hebrew University & Alma College (pwtaylor@mattii.alma.edu)

Mechanisms underlying reliable or 'honest' signaling have fuelled ample controversy in discussions of communication. The handicap mechanism is now widely accepted as a strategic constraint on cheating by signalers. Handicap signals are deemed reliable by their costs; signalers must choose between investing in the signal or in other aspects of fitness. Resources allocated to the signal reflect the signaler's fitness budget because, on average, costs of cheating are not adequately balanced by social benefits. However, that signals may also be deemed reliable by their design, regardless of costs, is not widely appreciated. We discuss 'indices' and 'amplifiers', reliable signals that may be essentially cost-free. Indices are reliable because they bear a direct and incorruptible association with the signaled quality rather than costs. Amplifiers do not directly provide information about signaler quality (i.e. are not quality indicators), but they facilitate assessment by increasing the efficiency with which receivers can assess pre-existing cues and signals that are associated with quality. We present results of experiments involving a jumping spider to illustrate how amplifiers can facilitate assessment of cues associated with physical condition without invoking the costs required for handicap signalling. (Behavioral Context; Mon. 11:15 AM - 11:30 AM; NMM2)

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Rockefeller University Field Research Center (tcherno@rockvax.rockefeller.edu)

We developed a technique for inducing rapid song imitation in juvenile zebra finches and analyzed the emergence of structured sounds from untutored vocalizations using a novel software that track adult sounds back to their developmental origin. We found that limited exposure to a song model induced the production of new sounds as soon as a day later. The new sounds included features of the song model. An analysis of trajectories of specific transformations suggests that a simple error correction mechanism is insufficient to explain the changes seen: We expected that the sounds imitated would appear first as crude versions of the final syllables and then be refined. Instead, we often saw that imitations of different sounds of the song model emerged from a common, relatively simple prototype sound that the pupil generated shortly after the onset of training. In addition, we expected to see a gradual reduction of the acoustic error between model and imitation. Instead, some acoustic features of the developing sounds approached the model through a complex trajectory that combined smooth transformations and abrupt changes. Our data suggest that the ontogeny of vocal imitation is a generative process of sound differentiation that combines preordained steps (innate knowledge) and error reduction. (Learning Social Signals; Sun. 4:30pm-4:45pm; NMM1)

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University of California - Los Angeles (jfthomas@ucla.edu)

Repertoires and song variability are mechanisms which many species of songbirds use to convey different types of information. For species which have only one song type, the ability to send different types of messages must be contained in the presentation of that single song type. This project addresses the functions of internote duration differences in the wrentit (Chamaea fasciata), a bird with a single song type. I performed playback experiments on marked pairs, manipulating internote duration using male and female typical vocalizations. Males responded more aggressively (faster time to approach, more countersinging) to male songs with shorter internote durations. Both males and females responded with faster time to approach to shorter internote durations in the female typical vocalization. Within song variation does play an important role in the communication system of the wrentit and is likely used to mediate territorial interactions. This mechanism may then also provide alternative methods of variation other than the development of repertoires. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Oregon (emartins@work.uoregon.edu)

Most communicative displays are composed of multiple signals in different sensory modalities. Lizards, for example, use both visual and chemical cues to defend territories and attract mates. An earlier comparative study of South American Liolaemus lizards suggested that there might be a negative relationship between visual and chemical cues across species. The Chilean Liolaemus clade seems to have increased the use of visual signals and decreased the use of chemical cues as compared to the Argentinean clade. Unfortunately, only rough measures of both visual and chemical signals were available for the comparative study. Thus, in this study, we tested this hypothesis empirically by examining the details of chemical and visual communication of two species, one from each clade. Field data indicate that Liolaemus robertmertensi, a member of the Chilean clade, uses relatively more visual than chemical signals than does L. koslowskyi, a member of the Argentinean clade. (Evolution of Signals; Tues. 10:15 AM - 10:30 AM; NMM1)

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Agricultural University & Icelandic University of Education (annagth@cc.usu.edu)

A group of 34 semi-wild Icelandic horses were studied in spring 1997. During the observation time 10 foals were born. Dominance rank was positively correlated with age and having a foal did not effect the rank position of the mare. All animals had special allogroom and play partners and preferred partners within their own sex-age groups. Fillies played less than colts. The mares preferred allogrooming with the mares of the same 'state' and allogroomed less after having a foal. Mares played less than other sex-age groups. Kinship was positively related with the choice of an allogroom /play partner. Only mares were seen to protect other mares with young foals. Mares spent about one fourth of their time resting and two thirds of their time eating. Barren mares spent more time in social interactions than pregnant mares and mares with a foal. Mares spent more time standing and resting the first week after the birth of their foal. Stallion like behavior of (pregnant) mares was observed. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Missouri - St. Louis (s982004@admiral.umsl.edu)

Field research exploring the functions and mechanisms of chemical communication for large mammalian species is quite sparse. Our on-going study marks the first systematic investigation of olfactory communication in free-ranging North American river otters, Lontra canadensis. By implementing live trapping and radio tracking methodology (via abdominal intraperitoneally implanted radio transmitters), home range, core area use, and association indices will be determined for 45-60 river otters from 3 sites throughout the state of Missouri. Using a habituation-discrimination paradigm and two-way preference testing, we will attempt to determine whether river otters can discriminate between scents from different individuals (e.g., "familiar" vs. "stranger", male vs. female) on the basis of chemical cues. In addition, microhabitat assessments will be made for all radio fix and successful trapping locations. Using GIS tools, these assessments will allow determination of habitat-use indices that can subsequently be applied at a much larger scale throughout much of this species range. These results will have implications that can be applied to the conservation and management of this species. Preliminary results are presented here. (John Paul Scott's Founders Poster Session; Tues. evening; Archer Hall Gym)

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Emory University & Yerkes Regional Primate Center (mtomasz@emory.edu)

Infant and juvenile rhesus macaques exhibit many sexually dimorphic behaviors (Wallen, 1996). This study investigated vocal behavior in male and female infant rhesus monkey separation-rejection vocalizations (SRV), and the effects of altering the prenatal hormone environment on these sex differences. Pregnant females received either exogenous androgen (Testosterone enanthate), an androgen antagonist (flutamide), or vehicle injections for 35 or 40 days during the second (early) or third (late) trimester of pregnancy. In control animals, females used more coos and arched screams than did males. In contrast, males used more geckers and noisy screams than did females. Females also had longer SRV bouts, used more calls, and used more types of vocalizations than did males. Early, but not late, androgen treatment produced females who vocalized in a male-typical manner. Similarly, early flutamide treatment produced males who displayed more female-typical SRVs. These results demonstrate sex differences in highly emotional vocalizations in infant rhesus macaques and provide evidence that the timing and form of prenatal hormonal exposure influences such vocalizations. (Parental Care 2; Sun. 1:30pm-1:45pm; NMM1)

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NCEAS (towner@nceas.ucsb.edu)

Dispersal, individual movement from one location to another, is a highly variable behavior. For most primates, biological anthropologists emphasize inbreeding avoidance and intrasexual competition for mates in explaining dispersal, and the main hypothesis for sex-biased dispersal links dispersal to mating systems. For humans, behavioral ecologists place greater emphasis on resource competition in explaining dispersal, and a large gap exists between what is known about dispersal and what is known about mating. I examine the link between dispersal and marriage using life history data for people from the small farming town of Oakham, Massachusetts (1750-1850). I find that dispersal status, timing, and destination were interconnected with marital status, timing, and spouse's place of origin. Men, unmarried individuals, and individuals with spouses from Oakham were less likely to disperse than their counterparts. Individuals with spouses from Oakham also married earlier than others. Dispersal infrequently preceded marriage, but instead was evenly split between coinciding with or following some time after marriage. Dispersal more often coincided with marriage for women, who were also more likely to disperse to their spouses town of origin than were men. An interpretation of these findings suggests little support for inbreeding avoidance, but rather a combination of access to mates and resources, as explanations for the variation found in dispersal from Oakham. (Dispersal; Sun. 5:30pm-5:45pm; Sale)

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University of Texas - Austin (fat0@mail.utexas.edu)

When a mate’s preferred characteristics deviate from the mean of a population, they are usually of greater magnitude. The wave-type electric fish, Apteronotus leptorhynchus, produces a quasi-sinusoidal electric organ discharge (EOD) which is used for electrolocation and communication and aids in individual and gender recognition: males discharge at higher frequencies than females. These fish possess electrosensory receptors which are tuned best to the individual’s own frequency, deviating frequencies requiring progressively higher intensities to elicit a comparable sensory response. To test the hypothesis that signals are preferred when they maximize sensory stimulation, I sequentially presented individuals with choices between two frequencies deviating from their own frequency a) by 3% (higher vs. lower), b) by 27% vs. 33% in the direction of the opposite sex, and c) by 5Hz vs. 30% in the direction of the opposite sex) and recorded preference scores for each stimulus. Whereas both males and females associate with signals corresponding to their probable electrosensory tuning curves, some males show a preference for lower over higher female frequencies, which are known to be inversely correlated with size and dominance. Initial preferences were reduced by increasing the intensity of the non-preferred signal. (Mate Choice 3; Mon. 1:30pm-1:45pm; NMM1)

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Universidade Federal de Santa Catarina & Dalhousie University (mvieira@cfh.ufsc.br)

This experiment investigated the relationship between the emission of ultrasonic vocalizations (UVs) and the behavioral and physical time-course of development in P. californicus. Thirty male and 26 female pups from 23 litters were used as subjects. From 1-23 days of age (day of birth = Day 0), behavioral observations were made for 6 min every second day, pups were weighed every five days and given a set of neurobehavioral tests every day. UVs, coordinated movements, neuromotor indicators and physical parameters were measured. The production of UVs peaked during the first week of development, remained stable from 7-14 days of age and decreased abruptly thereafter. Females vocalized significantly more than males. There was an inverse relationship between the emission of UVs and coordinated movements. The number of UVs emitted decreased significantly once pups displayed surface righting and their eyes opened. It is suggested that ontogenetic patterns of change in UV emission in P. californicus are inversely related to the development of coordinated movements, eye opening and surface righting. (General Poster Session; Tues. evening; Archer Hall Gym)

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Atkinson College (jvonk@yorku.ca)

Pigeons and several species of non-human primates have demonstrated learning for abstract natural concepts such as "tree", "water", and "human". Pictures of various exemplars of the categories are typically shown by slide and the subjects are required to press a key in response to instances of the correct category. The current study utilizes a touch screen to present photographs to six zoo-housed orangutans ranging in age from 2 to 41 years. The orangutans are required to touch the photo of the correct exemplar in order to obtain a food reward. Each subject is presented ten pairs of photos within each trial and receives only one trial per day. Each pair of photos represents a choice between two distinct categories such as orangutan versus human or orangutan versus "other primates". The photos are presented in random order with the pairings also being randomized. When the subjects reach consistent performance of at least 80% correct first choices they are given transfer trials which consist of all new photographs (exemplars) of the same concepts. One adult male consistently performs with above 80% accuracy on concept tests that vary according to the level of abstraction required. However his performance on earlier trials may have been partially mediated by the use of colour as a cue. (John Paul Scott's Founders Poster Session; Tues. evening; Archer Hall Gym)

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University of Dayton (octobre2@hotmail.com)

Assortative mating in animals based on aspects of body size is well established. There is less evidence for assortative mating based on ornamentation in species wherin both sexes are ornamented. We measured the expression of visual ornaments of Northern Cardinals (Cardinalis cardinalis): bright red upper breast plumage in males and bright red underwing coverts of females. A sample collected over a five-year period revealed that this population mates assortatively based on these ornaments. Previous research in another population showed that brighter male cardinals defended better territories and were mated to females that nested earlier in the season than the mates of duller males. Previous research in this population showed that brighter female cardinals provisioned their nestlings at higher rates than did duller females. Together, these findings suggest that high quality male and female cardinals mate with one another. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of New Hampshire (rjw@cs.unh.edu)

These experiments examined object retrieval by Norway rats based on sweetness, to better understand its relation to food hoarding. Rats retrieved either of two types of object placed in quantity at the end of an alley placed before the home cage for a short daily period. In Experiment 1 the effect of handling effort on the decision to consume vs. retrieve another object was tested by encasing the sweet object in a gelatin capsule. These were paired with a similar unsweetened object. Experiments 2 and 3 used sweet object/food pellet and sweet/non- or less-sweet pairings under adlib and deprivation conditions. Results were, (i) when handling was made difficult, retrieval of sweet objects was often followed by further retrieval rather than immediate consumption, (ii) under adlib feeding rats retrieved sweet objects in preference to food pellets; this preference was maintained under mild deprivation, but at _ 90% predeprivation weights, rats switched to a food pellet preference. Therefore, (i) sweetness can support object accumulation ("hoarding"), (ii) increased value of other foodstuff in relation to sweetness during deprivation, observed for feeding, also occurs for retrieval, (iii)the consume vs. retrieve decision holds across object properties that induce retrieval and underlies accumulation. (Foraging; Tues. 2:00pm-2:15pm; NMM2)

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University of Southern Mississippi (Susan.Walls@usm.edu)

We examined whether adult female mosquitofish (members of the Gambusia affinis/holbrooki species complex) discriminated between their own fry and those of another female during acts of cannibalism. We also asked whether the presence of alternative prey (dried bloodworms) altered the propensity for females to cannibalize fry. In laboratory trials, the behavior of females was observed when each was provided its own versus another female's fry, both in the presence and the absence of alternative prey. There was no difference in the mean proportion of fry eaten in each of the resulting four treatments. Females also did not differ in the frequency with which they moved toward, or away from fry, nor in their latency to consume their first fry, regardless of their relatedness to their prey. Under the conditions of our experiment, then, female mosquitofish do not appear to discriminate based on genetic relatedness during acts of cannibalism. It is possible that the enhanced growth and reproduction that is known to occur in cannibals of this species may ultimately outweigh the fitness costs of reduced offspring survival. (General Poster Session; Tues. evening; Archer Hall Gym)

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Rutgers University (wansaw@psychology.rutgers.edu)

Domestic chicks ( _Gallus gallus domesticus_ ) give distinct distress vocalizations or ""cheeps"" when separated from the mother hen and/or broodmates. The clucking of a broody hen, which is stimulated by cheeps, is known to inhibit these distress vocalizations. We examined the effects of different types of acoustic playback on the distress vocalizations of the chick. White Leghorn chicks, 3 to 6 days post-hatch, were separated from broodmates for 15 minutes and subjected to playback of either the clucking of a broody hen, their own distress vocalizations, or the distress vocalizations of a broodmate. No playback was given in the control condition. In line with previous observations, we found that the clucking of a broody hen reduced the number of distress vocalizations by 10-fold compared to the control condition and for some birds (38%) completely suppressed distress calls. Surprisingly, playback of the bird's own distress vocalizations reduced by 4-fold the number of distress calls emitted during the playback period. No difference was observed between playback of the bird's own distress calls and playback of a broodmate's distress calls in reducing the number of distress vocalizations. These findings provide further evidence for the role of self-stimulation in avian acoustic communication. (General Poster Session; Tues. evening; Archer Hall Gym)

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Southern Illinois University (waring@siu.edu)

Animal reactivity at specific distances has long been noted (e.g., Hediger, 1950, Wild Animals in Captivity). Terms such as flight distance and aggressive distance have been used by authors to identify two of these traits. For example, an animal will take flight only when an intruder has encroached to a certain distance. And when flight is not an option, the uneasy animal may become aggressive and defend itself against the intruder when the distance narrows to a specific point. Different behavioral situations have their own specific reactive distance, such as, alert distance, withdrawal distance, approach distance, strike distance, attack distance, submissive distance, individual distance, and maximum social distance. This paper will clarify and highlight examples. Each of these spatial phenomena remains consistent under like circumstances. Thus these distances can be highly relevant when herding, confining, or otherwise manipulating animals. Stress can be reduced and safety enhanced. But distances can alter as circumstances vary. It is noteworthy that changes in the spatial relationships over time can help assess the health, development, adaptation, and well-being of individual animals from afar. (Applied Animal Behavior; Tues. 2:30pm-2:45pm; Sale)

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University of Missouri - Columbia (welcha@missouri.edu)

Male displays traits are predictive of offspring quality in some species, although the functional relationship between display traits and offspring quality is not well understood. Female gray tree frogs prefer male calls of long duration, and offspring of males with long calls were of higher larval quality than offspring of males with short calls, in laboratory experiments. I tested whether variation in tadpole activity and metabolism contributed to an effect of call duration on larval period or mass at metamorphosis. I measured time spent feeding, ingestion rate, digestive efficiency, larval period, and mass at metamorphosis for tadpoles from eight maternal half-sibships (sired by one long-caller and one short-caller) which were raised individually at two food levels. Under low food conditions, offspring of long-callers were larger at metamorphosis than offspring of short-callers, but had similar larval periods; offspring of long- and short-callers did not differ in larval period or mass at metamorphosis under high food conditions. Tadpoles with higher ingestion rates tended to have shorter larval periods, but activity and metabolism did not affect mass at metamorphosis. Thus, the good genes effect detected in this experiment was not attributable to variation in activities or metabolism. (W.C. Allee Competition; Mon. 3:15pm-3:30pm; Sale)

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Indiana University (dajwhite@indiana.edu)

In a diversity of species, individuals depend on interactions with others to learn a vast amount of their behavioral repertoire. The impact of the social environment on development of mating behavior was investigated in cowbirds. Using naturally occurring variation in social experience, distinct social environments were created in aviaries for male and female cowbirds. Juvenile and adult females were housed in one of four conditions differing only in the age classes of males present. Groups of juvenile and adult females were housed with: (1) juvenile and adult males, (2) only juvenile males, (3) only adult males, or (4) no males. Across the four conditions, dramatically different cultures emerged from the differences in social composition. Males across conditions differed in: amount, quality, and type of song produced as well as the ways in which they used their song. Furthermore, both males and females differed across conditions in how they assorted spatially. Results are consistent with the hypothesis that the social environment can impact the developmental trajectory of mating behavior. (Learning Social Signals; Sun. 4:00pm-4:15pm; NMM1)

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Centre College (bcwhite@centre.edu)

Fifteen years ago a conservation program was established for the Barbados green monkey (Cercopithecus aethiops sabaeus). The features of this program illustrate many of the problems and controversial issues associated with conservation biology, including sustainable harvesting of a primate and conservation of an exotic species. These topics and the opportunity for close observation of wild vervets, make Barbados an ideal site for an undergraduate field course. The present paper describes a course that was completed in January of 1999. The class conservation project involved a survey of visitors and residents which was designed to contribute to a prior economic analysis of the conservation program. The results suggest an untapped potential for the monkeys to contribute to tourism. We also found mixed attitudes of Barbadians toward the monkeys which may have an important influence on the conservation program. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Montevallo (rwhitekiller@um.montevallo.edu)

There is clear evidence that avian ectoparasites can reduce host fitness. The purpose of this study was to determine whether densities of the mite Pellonyssus reedi, a common ectoparasite of House Sparrow nestlings, influence the rate at which parents feed their nestlings. To evaluate the effect of P. reedi on parental provisioning, we manipulated mite loads experimentally and then compared the total number of feeding visits, sizes of prey delivered, and divisions of parental workloads between pesticide-treated and sham-treated (control) nests. The application of pesticide lowered mite populations by 64% relative to control nests. Neither total feeding rate nor mean prey size delivered differed between experimental and control treatments, but the division of parental labor did. There were indications that male parents made the majority of deliveries in pesticide-treated nests; female parents made the majority of deliveries in control nests, but this could not be demonstrated statistically. (General Poster Session; Tues. evening; Archer Hall Gym)

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Mississippi State University (Hdw3@ra.msstate.edu)

Few vertebrates wound trees to forage on the resulting sap flow. The factors used to choose certain trees and avoid others are known only anecdotally. Most information on the winter behavior and ecology of Yellow-bellied Sapsuckers (Sphyrapicus varius) is limited to observations where they would not normally be during the winter. Observations began once a sapsucker was spotted and included the bird's behavior, sex, age, height and position in the tree, tree species, and whether the substrate was living or dead. Females were rarely observed and adults were more common than juveniles. Sapsuckers spent about 50% of the time excavating and maintaining sapwells. They preferred Hickory trees (Carya spp.) and tended to excavate wells on trees with a high percentage of the trunk covered with branches. These trees may have higher sugar concentrations because of increased photosynthetic area associated with a larger crown. Juvenile sapsuckers used parts of the trees differently than adults and also foraged at different heights. Such differences in the vertical distribution of foraging may help alleviate intraspecific competition based on age. (General Poster Session; Tues. evening; Archer Hall Gym)

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Wake Forest University (wintemf5@wfu.edu)

Southern flying squirrels scatter hoard nuts and nest socially during fall and winter. One of the automatic costs of sociality for G. volans could be increased cache pilfering by nest mates. This problem could be solved by either of two strategies: individuals are unrelated and hoard food selfishly, or they are related and hoard cooperatively. In a selfish strategy storing individuals should have an advantage in retrieving their caches relative to a pilfering nest mate. This advantage is necessary for hoarding to be evolutionarily stable in an unrelated group. In a cooperative strategy, pilfering should be higher, no storer's advantage should exist, and nest mates should be related so that pilfering costs could be offset through indirect fitness gains. We addressed the mechanisms of cache retrieval and pilfering among animals storing both odorless and typical nuts in a sand-filled arena containing variable numbers of landmarks. These results indicate that pilfering is uncommon and that spatial memory provides a storer's advantage. Outdoor experiments showed that solitary individuals larder hoard and social individuals scatter hoard food items. In both contexts individuals were active in the entire enclosure, indicating that neither a communal strategy nor individually distinct areas are used. A flexible, individualistic strategy is supported where spatial memory is the proximate mechanism that has allowed food hoarding to evolve in an unrelated, social group. (Dominance & Resource Defense; Tues. 11:45 AM - 12:00pm; NMM2)

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University of Texas - Permian Basin (cwotter@aol.com)

Burying beetles hide small vertebrate carcasses underground and process them for consumption by their young. These beetles are rare among invertebrates because they provide prolonged care of the young. They encounter competition for carcasses from sources such as conspecifics, ants and carcass decomposition. It is surmised there may not be many burying beetles in arid regions because of increased competition. Our research looked at the effect of competition with omnivorous ants Solenopsis spp. on burying beetles Nicrophorus marginatus reproductive success. Both were trapped in arid west Texas. We assessed the time to bury the carcass and number of larvae produced. Control trials were run with pairs of beetles and a mouse. Experimental trials were conducted with pairs of beetles, a mouse and ants. Initial results indicate that there is no difference in number of larvae produced, or time required to bury the carcass when ants were present or absent. Preliminary results suggest that a factor other than competition with ants may limit burying beetle reproductive success in arid environments. (General Poster Session; Tues. evening; Archer Hall Gym)

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University of Memphis (woodward@memphis.edu)

Over-marking occurs when one individual deposits its scent mark on the scent mark of a conspecific. Previous studies examined how meadow and prairie voles exposed to an over-mark later respond to top- and bottom-scent marks. Both species responded similarly to the top-scent but differently to the bottom-scent mark. This study examines their response to same-sex and mixed-sex over-marks to determine whether these responses reflect the different tactics individuals in non-monogamous (meadow voles) and monogamous (prairie voles) species use to attract mates and compete with rivals. In experiment 1 where donors and subjects were of the same sex, all subjects spent more time investigating the odor of the top-scent donor than the bottom-scent donor. In experiments 2 and 3, meadow voles exposed to a mixed-sex over-mark spent more time investigating the odor of the opposite-sex donor independent of its position in the over-mark. In contrast, in the same two experiments prairie voles spent more time investigating the opposite-sex donor if it was the top-scent donor. The data support the following speculations. First, over-marking serves a competitive function. Second, for a non-monogamous species the scent marks may be directed towards attracting multiple mates. Third, in a monogamous species, the scent marks may be directed towards establishing and maintaining a pair bond. (Mate Choice 3; Mon. 2:30pm-2:45pm; NMM1)

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University of Louisiana - Lafayette (jlw6433@louisiana.edu)

In territorial species, contests over territory possession and differences in territory quality may have important consequences for the mating systems. Territoriality is often related to "resource defense" polygyny, where females prefer males with the best territories. In stomatopod crustaceans, both males and females are territorial and live in burrows. I examined territorial behavior of the stomatopod Squilla empusa to determine if the mating system is related to resource defense. Resource defense polygyny hypothesis has several predictions: I tested three: 1) males should defend burrows (a resource) that are essential to females, 2) burrows are critical to female reproduction and thus males compete intensely for burrows, and 3) because female mate selection is influenced by territory quality, males are more selective in burrow choice. My results from laboratory experiments revealed that 1) burrow size is significantly associated with body size, 2) males changed territory ownership significantly more frequently than females, 3) individuals were significantly more likely to invade territories of same-sex, 4) sex of the resident did not influence the outcome of a territory dispute, and 5) sex of the closest neighbor significantly influenced possession of a burrow. These data indicate that burrows may represent equally important resources for both sexes. (Dominance & Resource Defense; Tues. 11:00 AM - 11:15 AM; NMM2)

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University of Southern Mississippi (Lorie.Yates@usm.edu)

Studies suggest that agonistic interactions among salamander species may play a vital role in their distributions. I conducted laboratory experiments to examine the responses of three salamander species (Plethodon mississippi, Eurycea guttolineata, Desmognathus fuscus) toward conspecific and heterospecific adults. I predicted that (1)_D. fuscus_ and P. mississippi would act aggressively toward E. guttolineata more than at either conspecifics or surrogate controls; (2) E. guttolineata would exhibit no significant aggression under any condition; (3) E. guttolineata would act submissively toward potential competitors D. fuscus and P. mississippi more than toward conspecifics and surrogate controls. I examined the behavior of 20 individuals of the three species under four treatments. E. guttolineata was less active in the presence of D. fuscus and P. mississippi. Both D. fuscus and P. mississippi acted aggressively toward E. guttolineata. These laboratory experiments yield predictions as to how these species influence each other's distributions in their natural habitats. Competitive exclusion by D. fuscus and P. mississippi may restrict the non-aggressive E. guttolineata to marginal habitats or "trap" it in a narrow zone between the two competitive dominants. (Dominance & Resource Defense; Tues. 10:00 AM - 10:15 AM; NMM2)

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Sonoma State University & White Mountain Research Station (beetle_lady@yahoo.com)

Male-male competition, female mate choice, or both may drive the evolution by sexual selection on male insects. I studied the relationship between mating success in the field and in the laboratory for the montane leaf beetle, Chrysomela aeneicollis. My study design allowed me to determine the relative roles of competition and mate choice and to correlate size and fluctuating asymmetry with mating success. I separated mate choice from competition effects by conducting two-choice tests with tethered and untethered males. Males found mating in the field mated significantly more compared with single males in nature. Male mating success in the laboratory and the field was not correlated with male size. On the other hand, female size was strongly positively correlated to mating success and I found evidence for size assortative mating. Chrysomela aeneicollis exhibits true fluctuating asymmetry, yet none of the FA indexes were related to mating success. In conclusion, field status can be used as an indicator of male mating success in C. aeneicollis. There was evidence that female choice influences male mating success. Female mating success was positively correlated with female size, which was positively correlated with the size of her mate. (Mate Choice 2; Sun. 2:30pm-2:45pm; NMM2)

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Wabash College (zielinsd@wabash.edu)

Fox squirrels store energy as fat and cached food, however little is known about the physiological conditions accompanying the utilization of these alternative energy storage forms. We exposed adult males to different patterns of food access (ad lib, 50% caloric restriction, and variable) in the laboratory throughout the year to characterize seasonal patterns in body mass regulation and caching behavior in response to different energetic challenges. Concomitantly, we monitored plasma glucose, triglyceride, leptin, and testosterone levels. Body masses peaked in the spring and increased after the squirrels experienced food deprivation, although the type of food access that followed food deprivation (constant or unpredictable) did not affect mass. Glucose and triglycerides decreased with body mass, but only during summer and fall. Body mass increased with leptin and decreased with testosterone. Caching rates increased after food deprivation, but did not vary seasonally. Caching rates also decreased with triglyceride, glucose and testosterone levels. These results begin to illuminate the proximate factors involved in squirrels' complicated energetic repertoire. (Mechanisms of Behavior; Mon. 11:45 AM - 12:00pm; NMM1)

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University of California - Riverside (mzuk@citrus.ucr.edu)

We examined the relationship between social dominance, immune response, and ornamentation in captive red jungle fowl by comparing these variables in males housed individually with a single female to those in the same males after they were placed in flocks with a male and three females. Males with larger combs before being placed in the flocks were more likely to become dominant, and dominant males' combs grew after flock formation while subordinate males' combs shrank. Immune response as reflected in hematocrit, immunoglobulin levels, and wing web swelling (a measure of cell-mediated immunity) was stronger in males that later became dominant, both before and after flock formation, although the difference between dominant and subordinate birds was more pronounced after multi-male groups were formed. Dominant and subordinate males also differed in the relationship between comb length and wing swelling. Among dominant males, individuals with larger combs had significantly larger swellings after flock formation, whereas subordinate males with relatively larger combs had worse cell-mediated immunity than those with smaller combs. Males of different quality thus pay different costs to maintain ornamentation and immune defense. (Immune Systems & Behavior; Weds. 1:45pm-2:00pm; NMM2)