Letters to Nature

Nature 414, 65-69 (1 November 2001) | doi:10.1038/35102054; Received 22 June 2001; Accepted 10 September 2001

Rapid responses of British butterflies to opposing forces of climate and habitat change

M. S. Warren1, J. K. Hill2,3, J. A. Thomas4, J. Asher1, R. Fox1, B. Huntley3, D. B. Roy5, M. G. Telfer5, S. Jeffcoate1, P. Harding5, G. Jeffcoate1, S. G. Willis3, J. N. Greatorex-Davies5, D. Moss5 & C. D. Thomas6

  1. Butterfly Conservation, Manor Yard, East Lulworth, Wareham, Dorset BH20 5QP, UK
  2. Department of Biology, University of York, PO Box 373, York YO10 5YW, UK
  3. Environmental Research Centre, Department of Biological Sciences, University of Durham, Durham DH1 3LE, UK
  4. Centre for Ecology and Hydrology, Dorset Laboratory, Winfrith Technology Centre, Dorchester, DT2 8ZD, UK
  5. Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS, UK
  6. Centre for Biodiversity and Conservation, School of Biology, University of Leeds, Leeds LS2 9JT, UK

Correspondence to: Correspondence and requests for materials should be addressed to C.D.T. (e-mail: Email: c.d.thomas@leeds.ac.uk).

Habitat degradation and climate change are thought to be altering the distributions and abundances of animals and plants throughout the world, but their combined impacts have not been assessed for any species assemblage1, 2, 3, 4. Here we evaluated changes in the distribution sizes and abundances of 46 species of butterflies that approach their northern climatic range margins in Britain—where changes in climate and habitat are opposing forces. These insects might be expected to have responded positively to climate warming over the past 30 years, yet three-quarters of them declined: negative responses to habitat loss have outweighed positive responses to climate warming. Half of the species that were mobile and habitat generalists increased their distribution sites over this period (consistent with a climate explanation), whereas the other generalists and 89% of the habitat specialists declined in distribution size (consistent with habitat limitation). Changes in population abundances closely matched changes in distributions. The dual forces of habitat modification and climate change are likely to cause specialists to decline, leaving biological communities with reduced numbers of species and dominated by mobile and widespread habitat generalists.