Using diet to assess the sensitivity of northern and upland birds to climate change

Abstract

High-latitude species are predicted to be vulnerable to climate change, particularly in the UK uplands, where many are at the margins of their southern range. There is increasing evidence that climate change may have an impact on populations through reductions in prey abundance. The diet of 17 insectivorous UK upland birds, and the sensitivity of their prey to likely climate change, were quantified from the literature and combined to produce an index of climate-change sensitivity for upland birds. Coleoptera and Diptera were the 2 most important prey taxa, with Tipulidae the most widely ingested prey family. Lepidoptera, Lumbricidae and Hymenoptera also comprised >20% of the diet of at least one upland bird species. Of these prey taxa, existing studies suggest that Tipulidae, Chironomidae and Lumbridicae may be particularly vulnerable to rising temperatures and increased frequency of drought projected to result from climate change. Therefore, the contribution of these 3 taxa to the diets of upland birds provides an index of climate-change sensitivity, which was correlated with an index of recent upland bird population trends. Future increases in temperature and drought frequency are expected to have an impact on populations of a range of upland bird species through reductions in prey availability, although further studies are required to test this hypothesis. Many upland areas have been artificially drained using ditches. Blocking these ditches may therefore provide a potential management option for climate-change adaptation in the UK uplands. © Inter-Research 2010.