The Evolution and Mechanisms of Social Recognition in Territorial Frogs.

Abstract

Many animals recognize familiar individuals, allowing them to perform a variety of important social behaviors such as feeding offspring or respecting dominance hierarchies. Behavioral ecologists have documented many examples of social recognition across diverse taxonomic groups, but we know relatively little about how animals recognize familiar individuals and how this behavior has evolved. My dissertation asks questions about mechanisms and evolution of social recognition through comparative research on several species of territorial poison frogs (Aromobatidae) that differ in whether territory neighbors are recognized and treated with less aggression than strangers. I show that neighbor recognition is associated with the defense of spatially-clumped reproductive resources, which results in a more complex social environment that may have served as a source of selection for recognizing nearby neighbors. The evolution of neighbor recognition was enabled by evolutionary changes in receiver cognition and not through the evolution of identity signals. Finally, male golden rocket frogs recognize neighbors by habituating to the temporal properties of their neighbors’ vocalizations, allowing them to discriminate between neighbors and strangers based on individual differences in these acoustic properties.