Interplay between plasma oxidative status, cortisol and coping styles in wild alpine marmots, Marmota marmota

Abstract

SUMMARYVariation in how individuals cope behaviourally and physiologically with stressors is widespread and can have a significant impact on life-history traits and fitness. Individual coping styles are characterised by differential behavioural and adrenocortical reactivity to various challenges. As stress hormones can affect the production of reactive chemical species and the antioxidant status, individuals with different coping styles may differ also in oxidative status. Field studies on wild mammalian populations are few in number and none so far has simultaneously tested the relationship between coping style, adrenocortical reactivity and oxidative status in the same individuals. We measured individual variation in coping styles along a proactive-reactive continuum together with variation in baseline and stress-induced plasma oxidative damage, plasma non-enzymatic antioxidant capacity and cortisol in wild alpine marmots, Marmota marmota. Confirmatory path analysis revealed that different coping styles are accompanied by different baseline and stress-induced plasma oxidative statuses. Our findings also highlight the potential role of cortisol as a mediator of such differences.Key words: coping style, personality, oxidative stress, cortisol, open-field test, mammals. THE JOURNAL OF EXPERIMENTAL BIOLOGY 375Oxidative stress and coping styles and physical activities in socio-sexual contexts, which are known to differ among coping styles [e.g. mice Mus musculus (Koolhaas et al., 1999) and great tits Parus major (Carere et al., 2001; Both et al., 2005;Groothuis and Carere, 2005)], could significantly affect the biomarkers of oxidative status and thus expose individuals to oxidative challenges of different magnitudes (e.g. Alessio, 1993;Costantini et al., 2008b). Oxidative stress results from an imbalance between the production of reactive chemical species and antioxidant defences, in favour of the former with a consequent increase in the rate of generation of oxidative damage (Sies, 1991;Halliwell and Gutteridge, 2007;Costantini and Verhulst, 2009). Oxidative stress may also be defined as a disruption of redox signaling and control (Jones, 2006), which regulate the redox balance and the antioxidant response to oxidative insults.The importance of oxidative stress as one component affecting the progression of diseases, ageing and health span (sensu Salmon et al., 2010) has been recognised for decades (Harman, 1956; Beckman and Ames, 1998;Halliwell and Gutteridge, 2007). However, only recently has it been recognised that oxidative stress may also represent an important modulator of trade-offs between life-history traits in wild populations (Costantini, 2008;Dowling and Simmons, 2009;Monaghan et al., 2009;. Recent studies have also suggested that differences in oxidative stress physiology may be associated with behavioural differences. In mice selected for different levels of aggression, Costantini et al. (Costantini et al., 2008b) found higher baseline non-enzymatic antioxidant capacity in less aggressive mice. In t...

Helpers influence on territory use and maintenance in Alpine marmot groups

“…16 Individual characteristics are also expected to influence territory size and shape (Boyer et al 2010). In two recent works on copying styles (see Koolhaas et al 1999) we showed that Alpine marmots present consistently repeatable behavioural traits (Costantini et al 2012, Ferrari et al 2013. Future research should investigate how space use could be affected by individual differences accounting for both the environment resource availability and density of the population (Dingemanse et al 2004).…”

Direct and indirect causal effects of heterozygosity on fitness-related traits in Alpine ibex

“…Each hypothesized DAG can be defined by the implied conditional independencies owing to the assumed causal links among the variables, which can then be statistically tested by translating them into structural equations [21,24]. While confirmatory path analysis and structural equation models have widely been applied in general ecology [25,26], ecophysiology [27,28] and evolutionary biology [29], we are not aware of any study using them in the field of molecular ecology.…”

Evidence for a mechanism of phenotypic integration of behaviour and innate immunity in a wild rodent: implications for animal personality and ecological immunology

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