Meeting Abstract
Male courtship signals often stimulate the production of sex steroids in both female and male receivers. Such effects benefit signalers by increasing receptivity in females, but impose costs on signalers by promoting sexual behavior and aggression in male competitors. We have previously shown that male green treefrogs, Hyla cinerea, counter these effects during close-range vocal exchanges that stimulate glucocorticoid production and suppress androgen production in rival males. We now assess whether acoustic signals produced by male H. cinerea also stimulate glucocorticoid production in females. The rationale for pursuing this question was based on our previous work showing that elevated glucocorticoid levels diminish female preferences for energetically costly calls. For example, we showed via dual-speaker phonotaxis experiments that female green treefrogs that were administered higher doses of corticosterone (CORT), and that possessed higher levels of CORT, were less likely to choose male advertisement calls broadcast at high rates, which females normally prefer. Unattractive males could thus increase their chances of acquiring mates if acoustic signals stimulate the production of glucocorticoids in females, as they do in males. We tested this hypothesis by examining the effects of broadcast vocalizations on sex steroid and CORT production in female H. cinerea. Results from this study will be presented.
