Get access

The effects of cyclic dynamics and mating system on the effective size of an island mouflon population

Authors

  • RENAUD KAEUFFER,

    1. Canada Research Chair in Behavioural Ecology and GRÉCA, Département des Sciences Biologiques, Université du Québec à Montréal, CP 8888 succursale centre-ville, Montréal, QC, Canada H3C 3P8,
    2. Laboratoire de Biométrie et Biologie Évolutive, UMR-CNRS 5558, Université de Lyon, Université Lyon I, 43 Bd du 11 novembre 1918, 69622 Villeurbanne cedex, France,
    Search for more papers by this author
  • DAVID W. COLTMAN,

    1. Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E9,
    Search for more papers by this author
  • JEAN-LOUIS CHAPUIS,

    1. Département Écologie et Gestion de la Biodiversité, UMR 5173 MNHN-CNRS-P6, Muséum National d’Histoire Naturelle, CP 53, 61 rue Buffon, 75005 Paris, France
    Search for more papers by this author
  • DENIS RÉALE,

    1. Canada Research Chair in Behavioural Ecology and GRÉCA, Département des Sciences Biologiques, Université du Québec à Montréal, CP 8888 succursale centre-ville, Montréal, QC, Canada H3C 3P8,
    Search for more papers by this author
  • DOMINIQUE PONTIER

    1. Laboratoire de Biométrie et Biologie Évolutive, UMR-CNRS 5558, Université de Lyon, Université Lyon I, 43 Bd du 11 novembre 1918, 69622 Villeurbanne cedex, France,
    Search for more papers by this author

Renaud Kaeuffer, Fax: (514) 987-4647; E-mail: kaeuffer.renaud@courrier.uqam.ca

Abstract

The Haute Island mouflon (Ovis aries) population is isolated on one small (6.5 km2) island of the remote Kerguelen archipelago. Given a promiscuous mating system, a cyclic demography and a strong female-biased sex ratio after population crashes, we expected a low effective population size (Ne). We estimated Ne using demographic and temporal genetic approaches based on genetic information at 25 microsatellite loci from 62 and 58 mouflons sampled in 1988 and 2003, respectively. Genetic Ne estimates were higher than expected, varying between 104 and 250 depending on the methods used. Both demographic and genetic approaches show the Haute Island Ne is buffered against population crashes. The unexpectedly high Ne likely results from the cyclic winter crashes that allow young males to reproduce, limiting the variance of male reproductive success. Based on individual-based simulations, we suggest that despite a strongly female-biased sex ratio, the effects of the mating system on the effective population size more closely resemble random mating or weak polygyny.

Ancillary