Chapter 6

Avoiding Predators and Finding Food

1. Behavioral biologists have several mathematical tools at their disposal to generate testable hypotheses about the behavior of their subjects. These include evolutionary game theory and optimality theory. Game theory views behavioral decisions as a game played by competitors. Here the better strategy (an inherited behavior) for making decisions about how to achieve reproductive success is one that takes into account the competing strategies of other individuals. In contrast, optimality theory attempts to predict the best way (in terms of greater fitness benefits than costs) for an individual to behave, often irrespective of what others are doing. Optimality theory is based on the premise that optimal traits are characteristics with a better benefit-to-cost ratio than any alternative traits that have arisen during the evolution of a species.

2. To be able to survive long enough to reproduce, animals need to avoid predators and find food. Animals can escape predators alone or in groups, and either actively or passively. Active social defense includes mobbing behaviors and group vigilance, whereas passive social defense includes diluting or reducing risk, or confusing

predators. Solitary defense mechanisms include camouflage to blend in, or aposematic warning coloration to stand out and announce your distastefulness to most or all predators.

3. Conspicuous coloration may signal to predators that individuals are toxic. However, some species use warning coloration to mimic other species. Batesian mimicry occurs when a nontoxic species mimics a toxic one, whereas Müllerian mimicry occurs when two toxic species mimic each other.

4. Optimal foraging theory makes predictions about how animals maximize fitness while foraging, including the optimization of food type, patch choice, time spent in different patches, or patterns and speed of movement. Energy is the currency used in most optimal foraging models.

5. The assumptions that go into optimal foraging models are critical for assessing how well the data fit the models’ predictions. Adjusting the assumptions can often help improve a model’s fit. This process of refining the model based on the data available is a standard part of the scientific process.

6. Avoiding predators and finding food are linked, especially for species that are themselves the potential prey of other species. The landscape of fear describes how the fear by prey of being eaten influences their foraging and movement behavior.