Challenges for transboundary management of a European brown bear population

Pan-European legislation stimulates international cooperation to overarching challenges of large carnivore management across jurisdictions. We present an analysis for current transboundary brown bear (Ursus arctos) population management in Croatia and Slovenia. Slovenia's bear management attempts aimed to reduce human-bear conflicts, by limiting the size and distribution of the bear population, with a relatively frequent use of intervention shooting. In contrast, fewer conflicts occur in Croatia and bears have been traditionally managed as a valuable game species, with heavily male-biased trophy hunting. On average 9% of the estimated bear population was removed annually in Croatia and 18% in Slovenia for the years 2005–2010. In Croatia, a greater proportion of adult males were shot than in Slovenia (80% vs 47% of total hunted males, respectively). We model a scenario for the shared panmictic population and two scenarios assuming that Croatian and Slovenian bear populations were spatially closed. When isolated, each countries' policies lead to potentially undesired management directions. The Slovenian bear population showed a stable or slightly decreasing trend that maintained its sex and age structure, while the Croatian bear population showed an increase in size but with a possible lack of older male bear. The panmictic scenario showed that different management policies buffered each other out with the overall combined population trend being slightly increasing with a sustained age/sex structure. The recent geopolitical refugee crisis has led to the partial erection of border security fencing between the two countries. Our data illustrate how the impacts of constructed fencing put in place to address border security issues may also impact the fate of Europe's bear populations and other wildlife species that use shared ecosystems. Keywords: brown bear (Ursus arctos), Croatia, Slovenia, Modelling, Population dynamics, Transboundary managemen