SPATIAL SCALE OF LOCAL BREEDING HABITAT QUALITY AND ADJUSTMENT OF BREEDING DECISIONS

Authors

  • Blandine Doligez,

    1. Department of Evolutionary Ecology, Institute of Zoology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
    Search for more papers by this author
    •  Present address: CNRS UMR 5558, Université de Lyon, Université Lyon 1, Department of Biometry and Evolutionary Biology, Bâtiment Gregor Mendel, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne Cedex, France. E-mail: doligez@biomserv.univ-lyon1.fr

  • Anne Berthouly,

    1. Department of Evolutionary Ecology, Institute of Zoology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
    Search for more papers by this author
  • Damien Doligez,

    1. Institut National de Recherche en Informatique et Automatique (INRIA), Domaine de Voluceau-Rocquencourt, B.P. 105, 78153 Le Chesnay Cedex, France
    Search for more papers by this author
  • Marion Tanner,

    1. Department of Evolutionary Ecology, Institute of Zoology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
    Search for more papers by this author
  • Verena Saladin,

    1. Department of Evolutionary Ecology, Institute of Zoology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
    Search for more papers by this author
  • Danielle Bonfils,

    1. Department of Evolutionary Ecology, Institute of Zoology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
    Search for more papers by this author
  • Heinz Richner

    1. Department of Evolutionary Ecology, Institute of Zoology, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland
    Search for more papers by this author

  • Corresponding Editor: W. D. Koenig.

Abstract

Experimental studies provide evidence that, in spatially and temporally heterogeneous environments, individuals track variation in breeding habitat quality to adjust breeding decisions to local conditions. However, most experiments consider environmental variation at one spatial scale only, while the ability to detect the influence of a factor depends on the scale of analysis. We show that different breeding decisions by adults are based on information about habitat quality at different spatial scales. We manipulated (increased or decreased) local breeding habitat quality through food availability and parasite prevalence at a small (territory) and a large (patch) scale simultaneously in a wild population of Great Tits (Parus major). Females laid earlier in high-quality large-scale patches, but laying date did not depend on small-scale territory quality. Conversely, offspring sex ratio was higher (i.e., biased toward males) in high-quality, small-scale territories but did not depend on large-scale patch quality. Clutch size and territory occupancy probability did not depend on our experimental manipulation of habitat quality, but territories located at the edge of patches were more likely to be occupied than central territories. These results suggest that integrating different decisions taken by breeders according to environmental variation at different spatial scales is required to understand patterns of breeding strategy adjustment.

Ancillary