EAPSI: Anuran Communication Networks: Behavioral Responses to Female Reciprocal Calling

Legett Henry, Jacksonville Beach FL

Investigators

Abstract

Frog species worldwide are experiencing rapid declines and extinction. While habitat loss and disease threaten many species, the processes that have led to some declines are unknown or poorly understood. In order to identify the causes of these declines, and develop effective conservation efforts, a deeper understanding of frog ecology and behavior is necessary. This project will investigate ecological tradeoffs of a unique mating behavior of the Asian grass frog, Fejervarya sakishimensis. By analyzing the tradeoffs of natural selection (from predators) and sexual selection (from mates), this behavior can be understood in the context of the ecological community. This research will be conducted in collaboration with Dr. Shizuko Hiryu and Dr. Ikkyu Aihara at Doshisha University in Kyoto City, Japan. The collaboration will allow for access to natural F. sakishimensis populations, as well as recently implemented technology essential for understanding frog behavior on a community level. Understanding the tradeoffs between selective pressures imposed within communication networks is key to understanding signal evolution. Animals producing mating signals are faced with a compromise between increased attractiveness to mates at the cost of increased detection by unwanted receivers or ?eavesdroppers? such as predators and parasites. Male frogs produce conspicuous mating signals at high intensities and the function of male advertisement calls has received considerable focus in the scientific literature. In contrast, females rarely vocalize, presumably to prevent the exposure of females to eavesdroppers. In a handful of species, however, females give calls in response to male vocalizations. It is likely that these calls evolved independently of male vocalizations, but their function remains relatively unknown. This project will investigate the response of different receivers (predators and male frogs) to female reciprocal calls in order to understand the ecological pressures constraining or reinforcing this rare behavior. This EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.