Positive impacts of important bird and biodiversity areas on wintering waterbirds under changing temperatures throughout Europe and North Africa

Migratory waterbirds require an effectively conserved cohesive network of wetland areas throughout their range and life-cycle. Under rapid climate change, protected area (PA) networks need to be able to accommodate climate-driven range shifts in wildlife if they are to continue to be effective in the future. Thus, we investigated geographical variation in the relationship between local temperature anomaly and the abundance of 61 waterbird species during the wintering season across Europe and North Africa during 1990-2015. We also compared the spatio-temporal effects on abundance of sites designated as PAs, Important Bird and Biodiversity Areas (IBAs), both, or neither designation (Unlisted). Waterbird abundance was positively correlated with temperature anomaly, with this pattern being strongest towards north and east Europe. Waterbird abundance was higher inside IBAs, whether they were legally protected or not. Trends in waterbird abundance were also consistently more positive inside both protected and unprotected IBAs across the whole study region, and were positive in Unlisted wetlands in southwestern Europe and North Africa. These results suggest that IBAs are important sites for wintering waterbirds, but also that populations are shifting to unprotected wetlands (some of which are IBAs). Such IBAs may therefore represent robust candidate sites to expand the network of legally protected wetlands under climate change in north-eastern Europe. These results underscore the need for monitoring to understand how the effectiveness of site networks is changing under climate change.Peer reviewe

Habitat- and species-mediated short- and long-term distributional changes in waterbird abundance linked to variation in European winter weather

Aim Many species are showing distribution shifts in response to environmental change. We explored (a) the effects of inter-annual variation in winter weather conditions on non-breeding distributional abundance of waterbirds exploiting different habitats (deep-water, shallow water, farmland) and (b) the long-term shift in the population centroid of these species and investigate its link to changes in weather conditions. Location Europe. Methods We fitted generalized additive mixed Models to a large-scale, 24-year dataset (1990-2013) describing the winter distributional abundance of 25 waterbird species. We calculated the annual and long-term (3-year periods) population centroid of each species and used the winter North Atlantic Oscillation (NAO) index to explain the inter-annual and long-term shifts in their location. Results (a) Year-to-year southwestwards shifts in the population centroids of deep- and shallow-water species were linked to negative NAO values. Shallow-water species shifted northeastwards associated with positive NAO values and the distance shifted increased with increasing NAO. Deep-water species shifted northeastwards up to zero NAO indices, but showed no further increase at higher NAO values. (b) Deep-water species showed long-term northeastwards shifts in distributional abundance throughout the 1990s and the 2000s. Shallow-water species, on the other hand, shifted northeastwards during the 1990s and early 2000s, but southwestwards thereafter. There were no significant links between the NAO and year-to-year movements or long-term shifts in farmland species' population centroid. Main Conclusions We provide evidence for a link between both year-to-year and long-term changes in waterbird winter distributional abundances at large geographical scales to short- and long-term changes in winter weather conditions. We also show that species using shallow water, deep-water and farmland habitats responded differently, especially at high NAO values. As well as important ecological implications, these findings contribute to the development of future conservation measures for these species under current and future climate change