Fecal glucocorticoids document stress in female Barbary macaques (Macaca sylvanus)

Patterns of received aggression and the endocrine response were related to an increase in fecal glucocorticoid metabolites in an intact semifree-ranging group of Barbary macaque females in order to quantify the social stress incurred over a 20-week observation period. The novel result showed that immunoreactive cortisol and 11-oxoetiocholanolone found in the feces can indeed determine the endocrine response of the adrenal gland after a social stressor. After HPLC separation of pooled fecal samples, EIA analyses using three different assays (corticosterone, cortisol, and 11-oxoetiocholanolone) to quantify immunoreactive steroids showed that the corticosterone EIA had no distinctive immunoreactive peaks. Cortisol and 11-oxoetiocholanolone immunoassays showed respectively four and two immunoreactive substances. Time series analyses revealed a behaviorally initiated increase in concentrations of cortisol and 11-oxoetiocholanolone equivalents. Furthermore, both hormone curves exhibit comparable time functions. Either antibody is very suitable for determining glucocorticoid secretion after periods of stress.