Impact of future climate change and land-use change on habitat suitability for a long-distance avian migrant under diverse socioeconomic-emission scenarios

Climate change and the alteration of land-use and land-cover (LULC) on a global scale presents a notable threat to biodiversity, with a particular impact on long-distance migratory birds. Nonetheless, our comprehension of how these changes specifically affect these avian migrants remains limited. To address this knowledge gap, species distribution models offer a valuable tool as they allow for projecting habitat suitability and provide insights into a species’ ecological responses to changing environmental conditions. In this study, we utilize modelled climate and LULC data spanning from 2015 to 2100, coupled with GPS tracking data and open-source occurrence data of European Nightjars (Caprimulgus europaeus), to assess how suitable habitat might be affected by changes in climate and LULC under different emission and socio-economic scenarios. Our models show that climate change alone may expand suitable habitat, particularly under high-emission scenarios, while LULC change generally exerts a constraining effect across annual cycle stages. While some scenarios indicate overall stability in the amount of suitable habitat, our spatially explicit results reveal that these entail substantial redistribution of suitable habitat which may disrupt migration patterns and increase energetic costs. Our findings underscore the importance of explicitly considering spatial and temporal aspects in assessments of global change impacts on migratory species and highlight the need for targeted conservation interventions in critical stopover zones to safeguard the species' future amidst global environmental change.