Predation on adult moose Alces alces by European brown bears Ursus arctos

Several North American studies have reported significant predation rates on moose Alces alces by brown bears Ursus arctos. We documented predation on moose by brown bears in south-central Sweden, where brown bears and moose occurred at estimated densities of 10-30 and 400-1,340/1,000 km(2), respectively. Bears killed 0.8% of radio-collared adult female moose (i.e. >= 1 year old) annually and no male moose (>= 1 year old). Bear predation was the least important mortality factor we documented. Based on tracking brown bears on snow during spring we recorded one successful hunt for every 372 km of tracks and documented attacks only by adult bears and successful attacks only by adult males. Autopsy of moose older than calves that were killed by brown bears revealed that yearlings were more prone to predation than older moose, and that older (i.e. >= 2 years) cows were more vulnerable to predation than older bulls. Our study suggests a lower tendency for Scandinavian brown bears to prey on moose compared to most of the North American studies.