Meeting Abstract

47.3  Jan. 6  Corticosterone mediation of antipredator responses in male lizards with alternative reproductive tactics THAKER, M.*; HEWS, D.K.; LIMA, S.L.; Indiana State University; Indiana State University; Indiana State University mthaker@indstate.edu

Most vertebrates respond to acute and chronic stressors with increased plasma concentrations of glucocorticosteroids (CORT), yet few studies examine behavioral consequences of increases in CORT. Indeed, no study in any vertebrate species has examined the subsequent effects of elevated CORT on behavioral responses to predation risk. We examined the behavioral effects of acute exogenous CORT elevation in male tree lizards (Urosaurus ornatus) with alternative reproductive tactics (ART). In our study population, territorial males have a blue patch on an orange dewlap (OB males) and non-territorial males lack the blue (O males). Social behaviors of males with a mottled dewlap are uncharacterized but these males were included. Using noninvasive dermal patches, we acutely elevated CORT levels in all male morphs and recorded behavioral responses of these males when exposed to a collared lizard (Crotaphytus nebrius) predator in outdoor enclosures. When exposed to predation risk, males with CORT patches responded more quickly, hid longer, and displayed more than control-patched males. O males were more fearful than other male morphs and were most sensitive to elevations in CORT. Field measures of antipredator responses of all male morphs were consistent with our laboratory findings. In sum, the influences of CORT on antipredator behaviors of males with ART suggest differences in selective pressures faced by males, especially in the context of sensitivity to predation risk.