Does Individual Performance Influence Antipredator Behavioral Strategy Choice in Chameleons?
Animals are under a constant selective pressure to avoid predation. They are often equipped with several anti-predatory behavior strategies based on their morphology, physiology and behavior. Maintaining a suite of behaviors allows animals to choose strategies that may be better equipped for particular environments and types of predators. Chameleons are a particularly interesting model to study the relationship between these adaptations because of how they have specialized to their environment. These animals have adapted traits that are well-suited for a largely arboreal lifestyle, but as a consequence, produce relatively slow locomotion. As a result, they may need to rely on alternative strategies that do not hinge on speed. Chameleons may still choose to flee to avoid predation, but they may also undergo cryptic color changes or behave aggressively. Previous work also suggests that their antipredator strategies vary significantly with body size and habitat type. We examined the functional basis for variation in antipredator behavioral decisions in veiled chameleons (Chamaeleo calyptratus) of small, medium, and large size classes. Individuals underwent a series of mock predation trials and their behaviors were classified into "fleeing," "crypsis", "aggression", or "other." We then quantified the performance capacities underlying each strategy by measuring sprint speed and acceleration for fleeing, degree of color change for crypsis, and bite force for aggression. Our results indicate that certain performance capacities across size classes influence which strategy is chosen during mock predation trials. The importance of the functional capacity to perform each behavior in antipredator behavior decision making provides considerable insight into the relationship between behavior, environment, and physiology.
Christopher V. Anderson
Drown, Rachel M., "Does Individual Performance Influence Antipredator Behavioral Strategy Choice in Chameleons?" (2020). IdeaFest. 41.