The buffer effect and large-scale population regulation in migratory birds

@article{Gill2001TheBE,
  title={The buffer effect and large-scale population regulation in migratory birds},
  author={Jennifer A. Gill and Ken Norris and Peter M. Potts and T{\'o}mas Gr{\'e}tar Gunnarsson and Philip W. Atkinson and William J. Sutherland},
  journal={Nature},
  year={2001},
  volume={412},
  pages={436-438}
}
Buffer effects occur when sites vary in quality and fluctuations in population size are mirrored by large changes in animal numbers in poor-quality sites but only small changes in good-quality sites. Hence, the poor sites ‘buffer’ the good sites, a mechanism that can potentially drive population regulation if there are demographic costs of inhabiting poor sites. Here we show that for a migratory bird this process can apply on a country-wide scale with consequences for both survival and timing… 
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