Global range dynamics of the Bearded Vulture (Gypaetus barbatus) from the Last Glacial Maximum to climate change scenarios

Abstract

Species' ranges are dynamic, particularly at large temporal scales. The reconstruction of range dynamics has an obvious biogeographical interest and might also help to frame current knowledge on the ecology and conservation of a species within a wider biogeographical context. The Bearded Vulture Gypaetus barbatus is a charismatic high‐altitude species occurring along mountain ranges of the Old World. The species has experienced a global range contraction in the last century mainly due to unintentional poisoning and direct persecution. Despite its declining status and high habitat specialization, little is known about how climate change is impacting the distribution of suitable habitat, or about global past range dynamics of the species. We modelled the current distribution of Bearded Vulture throughout its entire range and projected the Last Glacial Maxima (LGM), Mid‐Holocene (MH) and future distribution under 2070s climate change scenarios. Overall, our models predicted that expansion of suitable areas at more northern latitudes for 2070, mostly in Russia and China, does not compensate for range contraction at more southern latitudes, resulting in a global loss of 15% of suitable habitat. Our fine‐scale predictions of habitat contraction due to climate change will assist in identifying current portions of the range that might be particularly vulnerable in coming years. African populations (34% decrease) and more thermic areas in Asia are the most impacted areas, and should be at the forefront of future monitoring and conservation efforts. Our models suggest that the predicted contraction in habitat suitability during the 21st century largely continues the contraction experienced since the LGM (7% decline), albeit over a much shorter period of time. From a biogeographical perspective, our models suggest that there have not been relevant changes in the arrangement of the main suitable areas for the species since the LGM. This result challenges some of the main hypotheses proposed to explain the observed genetic structure of the global population.