Influence of habitat quality, patch size and connectivity on colonization and extinction dynamics of collared pikas Ochotona collaris

Authors


Dr David S. Hik, Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada. Tel: (780) 492 9878; Fax: (780) 492 9234; E-mail: dhik@ualberta.ca

Summary

  • 1The effects of habitat quality, patch size and connectivity between patches on patterns of local extinction and colonization of collared pikas were studied over 7 years in alpine meadows in the south-west Yukon.
  • 2Although adult population size independently had a significant influence on patch extinction, its influence was minimal when other variables were included in generalized linear models. Instead, an index of habitat quality and the connectivity of a patch were found to be the best predictors of pika extinction.
  • 3Similarly, patch connectivity only partly explained the recolonization of talus patches by pikas. Other patch characteristics, including aspect, amount of vegetation within the patch and an index of habitat quality based on survival probability of pikas also had a significant influence on recolonization.
  • 4These results suggest that the influence of patch quality on local extinction and recolonization need to be more fully incorporated into metapopulation models.

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