Meeting Abstract
Whether hormonal differences among males that conditionally alternate between mating tactics are a cause or consequence of behavioral expression is central to understanding the mechanisms regulating the adoption of a particular tactic. This issue is pertinent to alternative mating tactics in anurans because the social-acoustic environment can mediate changes in both tactic expression and hormone levels. Hence, it is not clear whether males adopt different tactics in response to rival male signals, hormone levels, or both. Here we address this problem in male green treefrogs, Hyla cinerea, using vocal playback experiments combined with measurement of circulating hormone levels, call attributes, body size and body condition. Despite our previous work showing that individual differences in corticosterone (CORT) and androgen levels can arise during social interactions and are casually related to tactic expression in this species, playback experiments revealed that hormone levels did not predict whether a male adopted non-calling satellite behavior or continued to call in response to broadcast advertisement calls. Rather, smaller males in poorer body condition that produced shorter duration calls were more likely to adopt satellite behavior in response to the broadcast stimulus. Collectively, our results illustrate that several approaches should be taken to address the potential bidirectionality of hormone-behavior relationships because multiple factors can influence mating tactic expression.
