Decision-Making in Przewalski Horses (Equus ferus przewalskii) is Driven by the Ecological Contexts of Collective Movements

Authors

  • Marie Bourjade,

    1.  Laboratoire d’Ethologie Animale et Humaine, Centre National de la Recherche Scientifique, Université de Rennes 1, Rennes, France
    2.  Association Takh pour le cheval de Przewalski, Station Biologique de la Tour du Valat, Arles, France
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  • Bernard Thierry,

    1.  Département Ecologie, Physiologie & Ethologie, IPHC, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
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  • Myriam Maumy,

    1.  Institut de Recherche Mathématique Avancée, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
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  • Odile Petit

    1.  Département Ecologie, Physiologie & Ethologie, IPHC, Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France
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Marie Bourjade, UMR CNRS 6552 Laboratoire d’Ethologie Animale et Humaine – Ethos, Université de Rennes 1, Campus de Beaulieu, Avenue du Général Leclerc, F-35042 Rennes Cedex, France.
E-mail: marie.bourjade@gmail.com

Abstract

We addressed decision-making processes in the collective movements of two groups of Przewalski horses (Equus ferus przewalskii) living in a semi free-ranging population. We investigated whether different patterns of group movement are related to certain ecological contexts (habitat use and group activity) and analysed the possible decision-making processes involved. We found two distinct patterns; ‘single-bout’ and ‘multiple-bout’ movements occurred in both study groups. The movements were defined by the occurrence of collective stops between bouts and differed by their duration, distance covered and ecological context. For both movements, we found that a preliminary period involving several horses occurred before departure. In single-bout movements, all group members rapidly joined the first moving horse, independently of the preliminary period. In multiple-bout movements, however, the joining process was longer; in particular when the number of decision-makers and their pre-departure behaviour before departure increased. Multiple-bout movements were more often used by horses to switch habitats and activities. This observation demonstrates that the horses need more time to resolve motivational conflicts before these departures. We conclude that decision-making in Przewalski horses is based on a shared consensus process driven by ecological determinants.

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