Meeting Abstract

P1.71  Thursday, Jan. 3  Seasonal variation in the hormonal responses of timber rattlesnakes (Crotalus horridus) to reproductive and environmental stressors LUTTERSCHMIDT, William I.*; LUTTERSCHMIDT, Deborah I.; MASON, Robert T.; REINERT, Howard K.; Sam Houston State University; Oregon State University; Oregon State University; The College of New Jersey Lutterschmidt@shsu.edu

We investigated seasonal variation in the effects of capture stress on corticosterone, testosterone, and estradiol in a population of timber rattlesnakes (Crotalus horridus) within the Tiadaghton State Forest of northcentral Pennsylvania. This study was conducted as part of a larger investigation evaluating the influences of timbering practices on the ecology, movement patterns, and mortality of rattlesnakes. In May, July, and September, we collected baseline and post-stress blood samples from 27 of 64 rattlesnakes that were monitored with radio-telemetry. Although both male and female rattlesnakes responded similarly to capture stress treatment with a significant increase in corticosterone, the magnitude of the stress response varied significantly with season. Capture stress also significantly increased testosterone concentrations of male snakes during the spring. In contrast, neither capture stress nor season significantly influenced plasma estradiol concentrations of female snakes. However, corticosterone responses to capture stress varied significantly with female reproductive condition: gravid snakes had significantly higher baseline corticosterone concentrations and a larger stress-induced increase in corticosterone than female snakes that were non-gravid or post-parturition. Finally, preliminary data suggest there is no relationship between baseline corticosterone levels and the amount of time rattlesnakes were associated with habitats affected by timber harvesting activities.