Meeting Abstract

P3.123  Thursday, Jan. 6  The effects of roads on adult Mountain White-crowned Sparrow glucocorticoid physiology WALLACE, BL*; CRINO, OL; MALISCH, JL; BREUNER, CW; University of Montana murraybrandy@hotmail.com

Proximity to roads increases stress in birds. Past research has focused solely on the effect of roads on changes in total corticosterone (CORT; the primary stress hormone in birds) ignoring the importance of binding globulins in regulating the stress response. Binding globulins such as corticosteroid binding globulin (CBG) bind to glucocorticoid stress hormones (e.g. CORT) preventing them from entering tissues, binding to receptors, and promoting physiological or behavioral responses to stressors. Measuring free CORT (the fraction of the hormone that is not bound to CBG) may provide a more biological relevant understanding of how organisms respond to stress. We examined correlations between proximity to a high traffic road and total and free CORT in adult Mountain White-crowned Sparrows (Zonotrichia leucophrys oriantha) using a nine year data set.