Hair cortisol concentrations correlate negatively with survival in a wild primate population

Abstract

BackgroundGlucocorticoid hormones are known to play a key role in mediating a cascade of physiological responses to social and ecological stressors and can therefore influence animals’ behaviour and ultimately fitness. Yet, how glucocorticoid levels are associated with reproductive success or survival in a natural setting has received little empirical attention so far. Here, we examined links between survival and levels of glucocorticoid in a small, short-lived primate, the grey mouse lemur (Microcebus murinus), using for the first time an indicator of long-term stress load (hair cortisol concentration). Using a capture-mark-recapture modelling approach, we assessed the effect of stress on survival in a broad context (semi-annual rates), but also under a specific period of high energetic demands during the reproductive season. We further assessed the power of other commonly used health indicators (body condition and parasitism) in predicting survival outcomes relative to the effect of long-term stress.ResultsWe found that high levels of hair cortisol were associated with reduced survival probabilities both at the semi-annual scale and over the reproductive season. Additionally, very good body condition (measured as scaled mass index) was related to increased survival at the semi-annual scale, but not during the breeding season. In contrast, variation in parasitism failed to predict survival.ConclusionAltogether, our results indicate that long-term increased glucocorticoid levels can be related to survival and hence population dynamics, and suggest differential strength of selection acting on glucocorticoids, body condition, and parasite infection.Electronic supplementary materialThe online version of this article (doi:10.1186/s12898-017-0140-1) contains supplementary material, which is available to authorized users.

Quantification of hair cortisol concentration in common marmosets (Callithrix jacchus) and tufted capuchins (Cebus apella)

“…Hair cortisol is increasingly used as a biomarker of chronic stress in nonhuman primates (Carlitz et al, ; Carlitz, Kirschbaum, Stalder, & van Schaik, ; Rakotoniaina et al, ). These measures can contribute to captive management by providing quantifiable data about how individuals respond to standard stressors in captive environments such as group formation, social separation, and social rank (Meyer & Hamel, ).…”

A Ten-Stage Protocol for Assessing the Welfare of Individual Non-Captive Wild Animals: Free-Roaming Horses (Equus Ferus Caballus) as an Example

“…However, interpretation of many of these indices is not straightforward. For example, while faecal [108][109][110] and hair [111,112] cortisol concentrations have been employed as a physiological index of stress [108][109][110][111][112], the significance of non-specific stress for an animal's mental experience is unclear [52,113]. Cortisol and many other physiological parameters are non-specific and do not indicate if the experience was positive (e.g., excitement, arousal) or negative (e.g., pain, fear, hunger).…”

Towards the validation of endogenous steroid testing in wildlife hair

“…Hair testing has been applied in wildlife to investigate numerous aspects of physiological ecology, including relationships among hormone levels and fitness proxies. For example, lower probability of survival was associated with higher hair cortisol in grey mouse lemurs (Microcebus murinus; Rakotoniaina et al, 2017) as well as higher hair corticosterone in root voles (Microtus oeconomus; Książek et al, 2017).…”