Patterns of Fecal Hormones in a Fenced Population of White-Tailed Deer

Analysis of voided feces has become a popular method of monitoring physiological parameters of many wildlife species. During the breeding seasons of 2006–2007 and 2007–2008, we collected fecal samples to determine concentrations of fecal glucocorticoid (FG) and fecal testosterone (FT) metabolites in a fenced population of white-tailed deer (Odocoileus virginianus). The purpose of the study was to determine how concentrations of FG and FT metabolites fluctuated throughout the breeding season, whether there was a difference betweenmales and females, and whether there was a relationship between the two hormones. FG and FT metabolites of males peaked during the rut, while female glucocorticoid levels remained relatively stable throughout the breeding season. We also observed a significant positive correlation between FG and FT metabolites. During the pre-rut and rut, males that exhibit high testosterone also had elevated glucocorticoid metabolite concentrations, but in the post-rut there was no relationship between FT and FG concentrations. We hypothesize that the effect of testosterone on glucocorticoid secretion is partially a result of testosterone-induced behavior, and not strictly a physiological link between the two hormones.