Ensemble models predict Important Bird Areas in southern Africa will become less effective for conserving endemic birds under climate change

27 May 2010

Aim: To examine climate change impacts on endemic birds, which are of global significance for conservation, on a continent with few such assessments. We specifically assess projected range changes in relation to the Important Bird Areas (IBAs) network and assess the possible consequences for conservation. Location: South Africa, Lesotho and Swaziland. Methods: The newly emerging ensemble modelling approach is used with 50 species, four climate change models for the period 2070-2100 and eight bioclimatic niche models in the statistical package BIOMOD. Model evaluation is done using the Receiver Operating Characteristic and the recently introduced True Skill Statistic. Future projections are made considering two extreme assumptions: species have full dispersal ability and species have no dispersal ability. A consensus forecast is identified using Principal Components Analysis. This forecast is interpreted in terms of the IBA network. An irreplaceability analysis is used to highlight priority IBAs for conservation attention in terms of climate change. Results: The majority of species (62%) are predicted to lose climatically suitable space. Five species lose at least 85% of their climatically suitable space. Many IBAs lose species (41%; 47 IBAs) and show high rates of species turnover of more than 50% (77%; 95 IBAs). Highly irreplaceable regions for endemic species become highly localised under climate change, meaning that the endemic species analysed here experience similar range contractions to maintain climate niches. Main conclusions: The South African IBAs network is likely to become less effective for conserving endemic birds under climate change. The irreplaceability analysis identified key refugia for endemic species under climate change, but many of these areas are not currently IBAs. In addition, many of these high priority areas that are IBAs fall outside of the current formal protected areas network.