High Habitat Potential but Limited Connectivity for Brown Bears Throughout Europe

Abstract

Aim Large carnivores worldwide have experienced substantial range contractions due to human activities, though several species are recolonising parts of their historical range. We aimed to assess current and potential European brown bear (Ursus arctos arctos) habitat as well as habitat connectivity on a continental scale.

Location The extended biogeographical regions of Europe, spanning from Portugal to central Russia, longitudinally, and from Norway to Türkiye, latitudinally. Excluding inland seas; this area covers 11,151,636 km2.

Methods We assessed habitat suitability throughout the study area using an ensemble species distribution model with nine submodels, using data from 10 European bear populations and Türkiye. We used the resulting habitat suitability maps to conduct a least-cost path connectivity analysis and an omnidirectional circuit connectivity analysis.

Main Conclusions Habitat suitability was strongly associated with low percentages of agricultural cover, low percentages of human development, and proximity to forest. Of our entire study area, 37% (4.09 million km2) is occupied or potentially suitable for bears. Connectivity analyses identified corridors that could facilitate movement among southern European bear populations, though agricultural land and human development limit connectivity between northern and southern European bear populations. Previous research estimated bears occupied 0.5 million km2 across the European Union, while our results estimate 1.82 million km2 of this part of our study area is potentially suitable for bears, though connectivity is limited. Our results inform conservation strategies and policy development for the future of brown bears in Europe, emphasising the need for transboundary conservation efforts.