Fecal glucocorticoid metabolites reflect same-day responses to veterinary capture in white-faced capuchins (Cebus imitator)

In many primates, long excretion lags limit the use of fecal glucocorticoid metabolites (fGCMs) for studying responses to discrete acute stressors. Validated lags to date span a broad but patchy sample of taxa: 22–36 h in catarrhines, such as chimpanzees ( Pan troglodytes) , yellow baboons ( Papio cynocephalus ), and macaques ( Macaca fascicularis) (Palme et al ., 2005 ); greater than 20 h in many callitrichids (Wark et al ., 2016 ); and greater than 24 h in brown spider monkeys ( Ateles hybridus ) and red howler monkeys ( Alouatta seniculus ) (Rimbach et al ., 2013 ). Tufted capuchins ( Sapajus spp.) are unusual, with fGCMs peaking 2.1–3.0 h after stimulated glucocorticoid release (Wheeler et al ., 2013 ), yet other Cebidae have not been tested with comparable challenges. Here, we tested whether a closely related taxon, the white-faced capuchin ( Cebus imitator ), exhibits similarly rapid fGCM excretion following a standardized stressor and whether fecal hormones can detect same-day responses to discrete events.