Environmental, biological, and social factors influencing fecal adrenal steroid concentrations in female Japanese macaques (Macaca fuscata)

Abstract

The ability to determine hormonal profiles of primate populations using non-invasive techniques can help to monitor physical fitness, stress, and physiological responses to environmental changes. We investigated fecal glucocorticoids (fGC) and DHEAS concentrations in captive Japanese macaques (Macaca fuscata) in relation to environmental, biological, and social factors. The subjects were female Japanese monkeys from 4 months to 31 years old housed in captivity (27 in social groups and 12 in single cages). Fecal samples were collected from all females, and behavioral data from the social groups during the mating season and the following birth season. Hormonal concentrations were analyzed by enzyme immunoassay. Our results revealed that both fGC and fecal DHEAS concentrations are higher in females housed indoors in single cages than in those living outdoors in social groups. We also found that fGC concentrations were higher in the cycling females during the mating (winter) season than the lactating females in the birth (spring) season. Age was negatively associated to both fGC and fecal DHEAS levels, but the relationship between age and fecal DHEAS was more evident in females housed indoors in single cages than in females housed in outdoor social groups. We did not observe any association of dominance rank with either fecal DHEAS or fGC. This study showed that measurement of fecal DHEAS and fGC can be a good method to assess stress in Japanese macaques. These findings provide insights about the physiology of these two adrenal hormones in female Japanese macaques, which can be applied to wild populations and is fundamental for captive management and conservation biology.

Patterns of Behaviour, Group Structure and Reproductive Status Predict Levels of Glucocorticoid Metabolites in Zoo-Housed Ring-Tailed Lemurs, Lemur catta

“…social rank, in any group as shown previously for females of other primate species (e.g. Macaca fuscata [Takeshita et al, 2014]) and some wild and free-ranging groups of L. catta [Pride, 2005;Starling et al, 2010]. This was surprising in light of the highly linear, stable hierarchies identified in our captive groups.…”

“…It could be speculated that by spending time indoors, the zoo-housed ring-tailed lemurs were able to reduce the physiological effort required to maintain homeostasis in cold conditions. Free-ranging and zoo-housed primates have high cortisol levels in the cold season compared to the warmer seasons [Beehner and McCann, 2008;Takeshita et al, 2014], which probably reflects the augmented physiological stress required to sustain homeostasis [Follenius et al, 1982]. However, since the study used data collected across both winter and summer months, a more parsimonious explanation could be that when indoors, subjects would probably have had increased opportunities to engage in close contact behaviour such as grooming, which has been shown previously to be associated with low cortisol levels in primates [Shutt et al, 2007;Foerster et al, 2011;Sonnweber et al, 2015].…”

Beyond Glucocorticoids: Integrating Dehydroepiandrosterone (DHEA) into Animal Welfare Research

“…Recently, Palme [ 116 ] published a thorough review of non-human animal studies that relied on fecal glucocorticoid metabolite analysis, identifying 1327 papers. Research investigating both glucocorticoid and DHEA(S) metabolites in feces is less common [ 116 , 169 , 170 ]. Because fecal hormone monitoring has become the method of choice for non-invasive sampling, our discussion of assay selection below will mainly focus on this approach.…”

Medicinal Properties in the Diet of Tibetan Macaques at Mt. Huangshan: A Case for Self-Medication

“…Stress disrupts health homeostasis, affecting reproductive function, overall health, and well-being of animals. Stress can be induced by both environmental and social factors, leading to physiological and behavioral imbalances (e.g., Takeshita et al 2013Takeshita et al , 2014Wooddell et al 2016). For example, primates living in seasonally cold habitats have a number of behavioral means for ameliorating cold stress, such as staying warm by sleeping and resting site selection, huddling, and, in one unique case, taking therapeutic hot spring baths (e.g., Hori et al 1977;Zhang and Watanabe 2007;Kelley et al 2016;Takeshita et al 2018).…”