Testosterone and estradiol predict male calling performance, but not performance-related tradeoffs, in competitive signaling environments in Cope’s gray treefrogs (Hyla chrysoscelis)

retained independent partial associations with calling performance. CORT showed no association with calling performance or strategy at either level. These results show that gonadal steroid state predicts asymmetries in calling performance between competitors while remaining unrelated to performance-related tradeoffs. By revealing strong positive correlations between gonadal hormones and energetic investment in calling, this study demonstrates how female preferences for high-performing callers can impose sexual selection on endocrine mechanisms regulating courtship behavior.