Meeting Abstract

P3.124  Wednesday, Jan. 6  Social stress in Potter traps LAWSON, B.K.*; MALISCH, J.L.; BREUNER, C.W.; University of Montana brennalawson@gmail.com

Acute capture and handling protocols are commonly utilized to characterize the glucocorticoid response to unpredictable stress in free-living vertebrates. In small passerines a common capture technique is seed-baited Potter traps. Each Potter trap is separated into two compartments, each with its own treadle triggered door. In white-crown sparrows (WCSP) glucocorticoid levels do not increase in response to trap containment within the first 15 minutes of capture. However, Potter traps contain two independent trapping units and it is possible for two birds to be captured per trap. It is not known if visual contact with a trapped conspecific elicits a glucocorticoid response. Here we compared baseline corticosterone (CORT; the primary glucocorticoid in birds) from male WCSP that were captured alone (n=25), with a conspecific male (n=14) or with a conspecific female (n=16). Baseline CORT levels were obtained during the egg-laying and incubation phase (June and July) from multiple years (2002-2008) of a long-term study population of WCSP at Tioga Pass Meadow, CA. Data was analyzed using a one-way ANCOVA with the main effect of trap occupant and the covariates date and maximum possible time in trap. We found that baseline CORT does not differ between males trapped alone and males trapped with a conspecific male. This finding is consistent with a previous study of male WCSP; staged-territorial intrusions did not elicit an increase in circulating CORT (Lynn et al., 2007, The Condor 109:173-180). Interestingly, males trapped with a conspecific female had significantly elevated baseline CORT as compared to males trapped alone or males trapped with a second male. There was not a significant effect of date nor time spent in the trap.