Predation on livestock and occasional attacks to people are the most conflict-causing interactions between large carnivores and humans. In turn, humans cause the majority of large carnivore mortality and have caused severe population reductions and extirpations worldwide. However, some large carnivore populations are now increasing and some people living in re-colonizing areas oppose their recovery. Minimising interactions between people and carnivores and analyzing the effects of human disturbance on wildlife are major goals for the management and conservation of these species. Carnivore behavioural responses to the perceived risk of being killed by humans may ultimately influence population distribution and demography.
The bear population in Scandinavia (~3300 bears in 2008; Kindberg et al. 2011) provides a good model to analyse the interactions between an expanding large carnivore population and people that use forests extensively. GPS-collared bears were approached by Moen et al. (2012) to document their reactions when meeting people in the forest. Most bears (80%) ran away and none behaved aggressively towards the observers, reinforcing the idea that European bears are generally not aggressive to people (Moen et al. 2012).
|A brown bear in Northern Europe. Photo credit: A. Ordiz|
We experimentally approached 52 GPS-collared brown bears (293 approaches on foot) from 2006 to 2011, to document the reaction of bears and to quantify the effect of disturbance on bear movements. Again, none of the bears reacted aggressively to the observers. Although the location of the animals was known, bears were usually in quite concealed spots and were physically detected in only 16% of the approaches; bears were seen in 42 approaches and heard in 6 approaches. However, the bears altered their daily movement patterns after the approaches. Bear movements increased at night and decreased during daytime (as also occurs after the start of the bear hunting seasons; Ordiz et al. 2012), which was most visible in days 1 and 2 after the approaches, altering bears’ foraging and resting routines. The shorter the distance between observers and bear and the denser the cover, the stronger the effect of the approach on bear movements, i.e. bear behaviour was especially disrupted where the bear detected humans at short distance and in the highly concealed spots where bears hide and rest during the day (Ordiz et al. 2011).
The lack of aggressive reactions to approaching observers reinforces the idea that European brown bears generally avoid people, although bears can respond aggressively if they feel threatened (e.g. when wounded). Management should secure the protection of cover where large carnivore populations persist, and the restoration of cover in areas where current carnivore recoveries are to succeed. Furthermore, people should be kept away from areas with shrub cover that provide concealment for resting carnivores during daytime, when people are outdoors. Unfortunately, the shrub layer is often destroyed, considered unproductive and/or to reduce fire risk, to increase pasture for cattle, or even to promote conservation of endangered species. Preserving cover and avoiding the most densely vegetated spots in the forests is a simple, but reliable way to avoid encounters with carnivores, which would ultimately benefit both human safety and large carnivore conservation.
Ordiz, A. a, Støen, O-G. a, b, Sæbo c, S., Sahlén, V. a, Pedersen, B. E. a, Kindberg, J. b & Swenson, J.E. a,d (2013). Lasting behavioural responses of brown bears to experimental encounters with humans. Journal of Applied Ecology, 50, 306-314 doi: 10.1111/1365-2664.12047
a Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5003, NO-1432 Ås, Norway.
b Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences. SE-901 83 Umeå, Sweden.
c Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Postbox 5003, NO-1432 Ås, Norway.
d Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway.
Kindberg, J., Swenson, J.E., Ericsson, G., Bellemain, E., Miquel, C. & Taberlet, P. (2011) Estimating population size and trends of the Swedish brown bear Ursus arctos population. Wildlife Biology, 17, 114-123.
Moen, G.K., Støen, O.-G., Sahlén, V. & Swenson, J.E. (2012) Behaviour of solitary adult Scandinavian brown bears (Ursus arctos) when approached by humans on foot. PLoS ONE, 7, e31699.
Ordiz, A., Støen, O.G., Delibes, M. & Swenson, J.E. (2011) Predators or prey? Spatio-temporal discrimination of human-derived risk by brown bears. Oecologia, 166, 59-67.
Ordiz, A., Støen, O.G., Sæbo, S., Kindberg, J. & Swenson, J.E. (2012) Do bears know they are being hunted? Biological Conservation, 152, 21-28.