Urinary cortisol levels of gray-cheeked mangabeys are higher in disturbed compared to undisturbed forest areas in Kibale National Park, Uganda

Habitat disturbance due to anthropogenic activities is a source of acute and chronic energetic stress in wild animals, including primates. Physiological responses to stress can compromise growth and reproduction, increase susceptibility to infection and lead to deleterious effects on health and conservation efforts. However, physiological measures of energetic stress in association with habitat disturbance are uncommon, especially for wild primate species. Here, we report differences in the stress hormone cortisol in two subpopulations of wild gray-cheeked mangabeys (Lophocebus albigena) inhabiting disturbed and undisturbed forest areas of Kibale National Park, Uganda. Cortisol levels were assessed via opportunistically and noninvasively collected urine samples using previously validated methods. We hypothesized that mangabeys in disturbed forest (DF) areas would experience greater stress and therefore exhibit higher average cortisol levels than conspecifics in nearby relatively undisturbed forest areas (UF). As predicted, mangabeys in the disturbed area had significantly higher cortisol levels (unpaired t-test of log transformed data, t?=?4.88, d.f.?=?108, P?