Multi-Night Territorial Behavior, Chorus Attendance, and Mating Success in Red-Eyed Treefrogs
Rachael Pulica '20
For many frog species that aggregate around ponds or streams, chorus attendance, the percentage of time or nights a given male is present and actively calling at an aggregation, is the strongest documented predictor of inter-male variation in reproductive success in the wild. Males are, thus, thought to compete via endurance rivalry, where available energetic reserves and individual physiology interact to determine chorus tenure. Frogs often exhibit territorial behavior within these aggregations, and territorial status is likely to influence a male's rate of energy expenditure. While males of several anuran species have been shown to hold territories across nights, it is not well understood whether such calling site fidelity is correlated with chorus attendance or mating success. Using subdermal RFID (PIT) tags to minimize disturbance to chorus structure, we quantified site fidelity, chorus attendance, and mating success for all male red-eyed treefrogs (Agalychnis callidryas) within a breeding aggregation in Panama across 50 consecutive nights. We found that nearly half of these males held territories across nights, that this cross-night territorial behavior was highly correlated with chorus attendance, and that chorus attendance was, in turn, the strongest predictor of male mating success. Males were most faithful to calling sites containing vegetation contiguous with adjacent sites and were more likely to remain at a site if they were successful in acquiring a mate there on the previous night. To our knowledge, this is the first study linking male site fidelity to chorus attendance and mating success in anurans. While female mate choice is an established driver of lineage diversification and the evolution of sexual signals, agonistic interactions between males at breeding aggregations are well-documented from a wide range of anuran taxa. The relationship between male–male interactions and mating success deserves broader research attention among anuran species.
Dougherty, R.P., Pulica, R.M., and Caldwell, M.S. 2022. Multi-night territorial behavior, chorus attendance, and mating success in red-eyed treefrogs. Ethology. 128(8): 608-619.