Foraging flexibility in the frog -eating bat, Trachops cirrhosus.

摘要

Males produce conspicuous advertisement signals to attract mates. These signals, however, often attract eavesdropping predators as well, so the benefit of obtaining a mate is balanced by the cost of an increased risk of predation. The evolution of sexual advertisement signals can be understood only through a thorough investigation of both predator and prey.;The Neotropical bat, Trachops cirrhosus, feeds on frogs and uses frog mating calls to locate its prey. On the basis of frog calls alone, bats can assess which frogs are palatable and which are poisonous. The tungara frog, Physalaemus pustulosus, produces two types of calls, simple and complex. Both female frogs and frog-eating bats prefer complex calls to simple ones, and as a result, male frogs face opposing forces of sexual and natural selection.;While there has been extensive study of mate choice behavior in the tungara frog, there has been comparatively little investigation of foraging behavior in the frog-eating bat. In my doctoral research, I investigate the sensory constraints and cognitive flexibility that shape foraging success in T. cirrhosus. Specifically, I address the following questions: (1) Are predator preferences for signal complexity influenced by localization performance? Do bats show better localization performance for complex calls than simple ones in silence, in noise, or in obstacles? (2) How fixed are predator associations for prey cues? Given novel foraging contexts, can predators rapidly track prey changes and alter pre-existing associations between prey cues and prey quality? (3) What mechanisms do predators use to learn about prey cues? Do social interactions play a role in prey acquisition behavior?;My results show that while T. cirrhosus is limited by biophysical constraints in its ability to localize prey, within these constraints it shows surprising flexibility. It can rapidly alter associations between prey cues and prey quality, and can quickly acquire novel foraging behavior via social learning. Together these studies offer new insights on the role of eavesdropping predators in the evolution of their sexually advertising prey, and shed new light on the role of learning in foraging success.