Coping with style: individual differences in responses to environmental variation

Abstract

Between-individual differences in coping with stress encompass neurophysiological, cognitive and behavioural reactions. The coping style model proposes two alternative response patterns to challenges that integrate these types of reactions. The “proactive strategy” combines a general fight-or-flight response and inflexibility in learning with a relatively low HPA (hypothalamic–pituitary–adrenal) response. The “reactive strategy” includes risk aversion, flexibility in learning and an enhanced HPA response. Although numerous studies have investigated the possible covariance of cognitive, behavioural and physiological responses, findings are still mixed. In the present study, we tested the predictions of the coping style model in an unselected population of bank voles (Myodes glareolus) (N = 70). We measured the voles’ boldness, activity, speed and flexibility in learning and faecal corticosterone metabolite levels under three conditions (holding in indoor cages, in outdoor enclosures and during open field test). Individuals were moderately consistent in their HPA response across situations. Proactive voles had significantly lower corticosterone levels than reactive conspecifics in indoor and outdoor conditions. However, we could not find any co-variation between cognitive and behavioural traits and corticosterone levels in the open field test. Our results partially support the original coping style model but suggest a more complex relationship between cognitive, behavioural and endocrine responses than was initially proposed.

Significance statement

Understanding the proximate mechanisms regulating the individual variation in responses to environmental challenges and changes is fundamental in ecological and evolutionary research. Theory predicts correlations between behavioural, cognitive and physiological traits to form alternative strategies named coping styles but recent studies report contrasting and mixed findings. We examined the relationship between a measure of endocrine state (concentrations of faecal glucocorticoid metabolites), two behavioural traits (boldness and activity) and two cognitive traits (speed and flexibility of learning) in 70 unselected bank voles (Myodes glareolus) under three different conditions. The findings partially support the original coping style model’s hypothesis and predictions. We found individual consistency of all traits. However, correlations between behavioural and cognitive aspects and endocrine state were found only in two of the three tested conditions, highlighting the need for further investigations and testing of theory.

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Acknowledgements

We thank Angela Puschmann for helping in the samples’ preparation, Edith Klobetz for carrying out the EIA, Julia Hoffmann and the Animal Ecology group of the University of Potsdam for helpful discussion and advice, and three anonymous reviewers for their constructive comments on a previous draft.

Funding

During manuscript preparation MD was funded by the German Science Foundation (DA 1377/4-1).

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Correspondence to Valeria Mazza.

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The authors declare that they have no competing interests.

Ethical approval

Ethical approval for involving animals in this study was given by the “Landesamt für Umwelt, Gesundheit und Verbraucherschutz Brandenburg” (reference number: V3-2347-44-2011, Ä6) and the “Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen” (reference number: 84-02.04.2016.A253) as well as by the ethical committees of the institutions where the study took place. This study complies with the ASAB/ABS Guidelines for the Use of Animals in Research and was conducted in accordance with all applicable international, national and institutional guidelines for the care and use of animals.

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Mazza, V., Dammhahn, M., Eccard, J.A. et al. Coping with style: individual differences in responses to environmental variation. Behav Ecol Sociobiol 73, 142 (2019). https://doi.org/10.1007/s00265-019-2760-2

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Keywords

  • Coping styles
  • Faecal glucocorticoid metabolites
  • Learning
  • Stress
  • Personality
  • Rodent