Proximity-dependent Response to Variably Complex Mating Signals in Túngara Frogs (Physalaemus pustulosus)


Karin L. Akre, Section of Integrative Biology, 1 University Station C0930, University of Texas, Austin, TX 78712, USA.


The plasticity of animal behavior allows individuals to maximize fitness in a wide range of contexts. Both production of and preference for mating signals are context-dependent according to internal factors such as hormonal state, and external factors such as predation risk. In many species, male-to-female proximity also defines an important context for mating communication. Males often possess short-distance courtship signals, and females often exhibit distance-related variation in signal response. Such variation in response may occur when a signal’s relevance changes with male-to-female distance, but it may also result from perceptual constraints that are unrelated to fitness. Túngara frogs produce variably complex advertisement calls, and sexual selection theory predicts that females should prefer calls of greater complexity. Preference tests, however, have not demonstrated consistent trends for preference between calls of variable complexity. We tested whether proximity to males influences female response to variable signal complexity and found that both preference and memory for signal complexity are proximity-dependent.