CALL TRAIT VARIATION IN MORELETT'S TREE FROG, AGALYCHNIS MORELETII, OF BELIZE

Calling behavior and the properties of a male's call directly affect mate choice and mating success in frogs. In this study, I investigated the difference in call properties within and among males of Agalychnis moreletii at a breeding population in Belize. As a first step toward understanding female preference for specific male advertisement calls, I examined the variation of call traits from 575 calls of 30 individuals. I described and quantified call properties both within and among males and examined the relationship between mating success and body size. All of the call traits that I examined exhibited significantly higher among-male variation than within-male variation. Static call properties such as dominant frequency and call amplitude had the lowest variation within and among males. Dominant frequency was negatively correlated with body size, supporting a body-size constraint for this call trait. Call properties such as call rates, mean pulses per call, and call durations displayed greater variability among males. Such variability in these dynamic call traits suggests energy, constraints because calling longer and calling more frequently are energetically costly. As a result, dynamic properties may be indicators of male quality and play, a greater role in mate choice. Indeed, males found in amplexus produced a greater number of calls and those calls were of longer durations and tended to have a shorter intercall interval. Here, I characterize call trait variation and document call properties as indicators of mating success in the process of sexual selection in anuran communication.