Projected reductions in climatic suitability for vulnerable British birds

Projections of species' distributions in future climates can aid adaptive conservation strategies. Although presence-absence or presence-only data have been extensively used for this purpose, modelling changes in spatial patterns of abundance provides a more sensitive tool for estimating species' vulnerabilities to climate impacts. We used abundance data from citizen science bird surveys in the UK and France to predict spatial patterns of future climatic suitability throughout Great Britain for 124 breeding bird species. We project that climatic suitability of Great Britain will increase for 44% of species and decline for 9% of species by 2080. Of the latter group, most are already red-listed for their severe long-term population declines. If our suitability projections translate into population changes, by 2080, conservation listing status will worsen for 10 species and improve for 28 species. Projected changes in climatic suitability translate into net gains of species abundance in northern and western areas and high turnover in community composition throughout Britain, particularly under medium- and high-emission scenarios. In conclusion, community-wide projections of changes in climatic suitability based on abundance indicate that bird assemblages throughout Great Britain will be impacted by climate change and that species already of concern are likely to be impacted hardest. Of the species projected to benefit, the ability of currently red-listed species to respond positively to climate without other interventions is unclear.