Stress in Yucatan spider monkeys: effects of environmental conditions on fecal cortisol levels in wild and captive populations

Abstract

In the Yucat´an Peninsula, spider monkeys Ateles geoffroyi yucatanensis are generally found in two contrasting conditions: large tracts of conserved forest or small fragments surrounded by human populations. In the present study, we analyzed fecal cortisol levels of spider monkeys to investigate whether environmental conditions have an influence on stress; specifically, we compared fecal cortisol across individuals living in conserved forests, fragmented forests and captive conditions (zoos and pets). Radioimmunoanalysis of fecal samples from 121 individuals indicated significant differences in mean cortisol for A. g. yucatanensis based on habitat type, with the lowest levels found in the conserved forest condition. The higher cortisol levels in both fragmented forest populations and in captive individuals may be the result of metabolic and behavioral stress. The mean male fecal cortisol concentration was significantly higher than that of females, and the fecal cortisol concentration was higher in the dry season compared with the wet season in a conserved habitat. Therefore, we emphasize the importance of considering sex and seasonality when monitoring fecal cortisol concentrations of spider monkeys, and more generally of frugivores, as they face a seasonal variation in food availability. Finally, our results suggest that forest fragmentation may create long-term stressors for spider monkeys, affecting the viability of populations living under such conditions.

Monitoring stress in captive and free-ranging African wild dogs (Lycaon pictus) using faecal glucocorticoid metabolites

“…), GC concentrations were higher in captive than in free-ranging individuals (Fanson et al, 2011;Marra et al, 1995;Rangel-Negrin et al, 2009;Terio et al, 2004). If the level of stress is indeed higher in captive animals than in free-ranging animals, then it might help explain poor reproductive success in captivity in some species (Carlstead and Shepherdson, 1994).…”

The hustle and bustle of city life: monitoring the effects of urbanisation in the African lesser bushbaby

“…However, assays for non-invasive hormone measurements need to be carefully validated in terms of applicability for the species-specific hormone matrix of interest to ensure a reliable quantification of respective glucocorticoid metabolites (Touma and Palme 2005). Monitoring faecal glucocorticoid metabolites (fGCM), as an index of stress, has been done on a range of wild diurnal primate species such as black howler monkeys (Alouatta pigra, Martínez-Mota et al 2007), Yucatan spider monkeys (Ateles geoffroyi yucatanensis, Rangel-Negrín et al 2009) and red-bellied lemurs (Eulemur rubriventer, Tecot 2013), where a high degree of human-primate interaction usually correlates with an increase in glucocorticoid levels (George and Crooks 2006;Tecot 2013). However, no study has so far reported the effect of anthropogenic disturbances for a nocturnal species, where the presumed reduced potential for human-primate interaction should be reflected in less distinct adrenocortical activity.…”

The Effect of Fission–Fusion Zoo Housing on Hormonal and Behavioral Indicators of Stress in Bornean Orangutans (Pongo pygmaeus)

“…We investigated the extent to which this housing approach affects stress levels in the orangutans by assessing hormonal and behavioral indicators of stress. The measurement of fGCM is widely used as a non-invasive tool to investigate adrenocortical activity and thus physiological stress load (Heistermann et al 2006;Lane 2006;Millspaugh and Washburn 2004;Rangel-Negrin et al 2009). Behavioral approaches also serve as a noninvasive way to assess stress in primates (Honess and Marin 2006).…”