Meeting Abstract

9.6  Sunday, Jan. 4  STRESS REACTIVITY AND REPRODUCTIVE SUCCESS PATTERSON, SH*; MACDOUGALL-SHACKLETON, B; HAHN, TP; BREUNER, CW; Univ. of Montana; Univ. of Western Ontario; Univ. of California at Davis; Univ. of Montana stephen1.patterson@umontana.edu

A common assumption in the glucocorticoid literature is that the glucocorticoid acute stress response is an adaptive trait. However, there is little direct evidence to support this claim. We test this hypothesis by exploring how variation in glucocortiocoid stress responsiveness relates to fitness in a breeding population of White-crowned Sparrow (Zonotrichia leucophrys). Individual fitness is estimated using the number of offspring fledged within a season and over a lifetime. We assign fledglings to adults using social parentage; for a subset of our data, we also use microsatellite data to assign genetic paternity. Glucocorticoid stress reactivity is measured from serial blood samples taken at 0-3, 15, and 30 minutes post-capture. Analysis is ongoing; results of this analysis will be discussed in a fitness framework. Future work will extend the microsatellite assignment of paternity to all fledglings and explore a possible relationship between glucocorticoid stress responsiveness and the tradeoff between survival and reproduction.