Generalists yet different: distributional responses to climate change may vary in opportunistic bat species sharing similar ecological traits

Climate change is among the key anthropogenic factors affecting species’ distribution, with important consequences for conservation. However, little is known concerning the consequences of distributional changes on community-level interactions, and responses by generalist species might have many ecological implications in terms of novel interactions with resident species. In this study, we applied Ecological Niche Models and niche analysis to three generalist bat species, Hypsugo savii, Pipistrellus kuhlii, and Pipistrellus pipistrellus, which share similar ecological traits and are sympatric in parts of their ranges. Our aims were to investigate how predicted climate change will affect species’ distribution and to analyse the degree of climatic niche overlap between the three species, in both the current and the future scenarios (2050 and 2070; Representative Concentration Pathways 4.5 and 8.5). Temperatures were the most important predictors influencing species’ range expansion in future. According to our models, Pipistrellus kuhlii and Hypsugo savii may expand their geographic ranges towards northern latitudes, whereas the geographic range of the less thermophilous Pipistrellus will shift northwards, resulting in it losing the southern portion in Europe. The already considerable degree of climatic niche overlap between the three species will increase further in future. On the basis of our findings, within the new areas potentially colonised by all three species in future, alterations in community-level balance might occur, bringing about effects that are only partially predictable. In view of this, we highlight the need for further research and improved monitoring of bat communities in areas that are predicted to be particularly vulnerable to climate change.