Supplementary ungulate feeding affects movement behavior of brown bears

Abstract

Food availability plays a key role in animal movements. Anthropogenic provisioning of food to wildlife is a common practice of unprecedented magnitude worldwide and is of increasing conservation concern. Ungulate supplementary feeding is widespread in game management; however its effects on non-target species have received little attention. Here, we investigate how ungulate feeding affects the movement behavior of a non-target species, the brown bear (Ursus arctos). We tracked bear movements in the Northeastern Carpathians (1500km2) and inventoried 212 ungulate feeding sites. We analyzed encounter rates of nine GPS-collared bears with ungulate feeding sites (1658km, n=49 tracks) and compared them with the corresponding encounter rate of simulated tracks. We also estimated the encounter rate with feeding sites using snow-tracking of unknown bears (232km, n=40 tracks). GPS-tracked bears encountered feeding sites three times more frequently (mean±SE=0.154±0.022 per km travelled) than would be expected if they were moving randomly (0.054±0.0010 per km random walk). The rate was even higher for snow-tracked bears, which visited on average 0.926±0.271 feeding sites per kilometer travelled. This suggests a link between the winter activity of some individuals and their frequent use of feeding sites. Bears seemed to rely on spatial memory and patrol known sites, independent of whether food was available at the feeding sites. This alteration of the natural behavior of species with behavioral flexibility, such as brown bears, could be interpreted as a sign of environmental degradation. Our results demonstrate an important effect of ungulate feeding on the movement ecology of non-target species. We warn of the impacts of this practice on species and ecosystems and highlight the need to preserve natural movement behaviors and urgently reevaluate management practices involving food provisioning to wildlife.