Laboratory Exercises in Animal Behavior - Crickets and Territory Defense - WorkSheet
Crickets and Territory Defense Worksheet
1. Explain why territory defense is analogous to an economical practice.
Individuals and species attempt to defend specific areas and maintain exclusive access to them only when the fitness benefits of doing so outweigh any costs. For example, owning rental property would only be "functional" if the income from the rent is greater than the expenses incurred by the property owner.
2. State two different types of territory defense.
1) A single individual defends an area against all others of the same sex and species.
2) Several individuals join together to defend the territory against other of the same, or of other species.
3. What is the one common theme that territories have?
Territories provide a valuable resource, such as food, nesting sites or shelter, to the residents that allows them to survive and reproduce.
4. What is the purpose of observing interacting males?
To determine if one appears dominant over the other, and if so, to identify the dominant behaviors.
5. Dominance status may represent an adaptation. Explain how.
Dominant individuals have priority of access to important resources. Characteristics that are associated with success in dominance interactions would thus be favored in natural selection because dominant individuals would survive and subsequently reproduce more often than subordinate individuals.
6. Some people mistakenly argue that territoriality (and other behaviors) are "good for the species" (that is, territory defense ensures the survival of the species). What is wrong with this argument?
Although territoriality (or any other behavior) may indeed be "good for the species" (for example, because it ensures adequate food supplies and prevents the number of breeding individuals from becoming too high), the advantages of behavior are usually best explained in terms of survival and reproductive success of individual animals (not species). Territoriality occurs primarily because territorial individuals survive and reproduce better than non-territorial ones.
