Identifying priority areas for restoring large mammal populations in the Caucasus Ecoregion

Abstract

Large mammals play critical roles in ecosystems, yet their populations are across the globe as a result of habitat loss, overhunting, and human-wildlife conflicts. Some of these threats have lessened considerably in parts of Europe, particularly in mountain regions, and this offers unique opportunities for restoring large mammal populations to ecologically functional levels. However, many species require active conservation planning and management for achieving this goal. We focused on the Caucasus Ecoregion, a global biodiversity hotspot at the crossroads of Europe, Central Asia and the Middle East, with a variety of large carnivore and herbivore species. The collapse of the Soviet Union in 1991 brought about major changes in this region, including armed conflicts, low levels of institutional control, and economic hardship. Altogether this resulted in plummeting populations of many large mammal species that today hold out only in small and fragmented populations. In contrast, the institutional changes in the post-Soviet countries have also led to widespread land-use changes, such as agricultural abandonment and declining livestock numbers, providing opportunities for restoring large mammal populations. We mapped suitable habitat for Bezoar goat (Capra aegagrus), European bison (Bison bonasus), Gmelin’s mouflon (Ovis orientalis) and Goitered gazelle (Gazella subgutturosa), all of which are of conservation concern, across the ecoregion. To do so, we used species distribution models, a range of environmental and human-disturbance-related covariates, and extensive datasets of large mammal occurrence. We then identified areas of high and low risk of human-wildlife conflict (e.g., hunting and/or competition with livestock), and assessed the connectivity among core habitat areas using cost-surface and circuit flow analyses in order to identify priority habitat patches for conservation interventions. Our results highlight widespread areas with suitable habitat for all species, including many areas with potentially low risk for human-wildlife conflicts. Most of these suitable habitat patches, however, are currently unoccupied (e.g., 60 out of 69 for European bison) and are largely outside the current protected area network (e.g., >80%% of priority areas for mouflons and Goitered gazelles). Many habitat patches are also fairly isolated in regards to extant populations, highlighting the need for protecting stepping stones and corridors, and for additional reintroductions. All countries contained several candidate sites for reintroductions, particularly in Russia, Azerbaijan and Georgia for European bison, in Armenia and Iran for mouflon, Azerbaijan and Georgia for Goitered gazelle, and all countries in regards to bezoar goat. Finally, our study highlights that habitat networks and key corridors extended across national borders, emphasizing the need for Ecoregion-wide cooperation, conservation planning and enforcement of wildlife protection laws.