Abstract

Animals adapt their foraging behavior to variations in food availability and predation risk. In Sweden, brown bears (Ursus arctos) depend on a nearly continuous intake of berries, especially bilberries (Vaccinium myrtilius) during late summer and early autumn to fatten up prior to hibernation. This overlaps with the bear hunting season that starts on 21 August. Bilberry occurrence varies across space, as does human-induced mortality risk. Here, we hypothesize that brown bears select for areas with a high probability of bilberry occurrence across a boreal forest ecosystem in Sweden (H1), and that human-induced mortality risk reduces bear selection for bilberries (H2). In addition, we hypothesized that hears that survived the hunting season avoided bilberry areas associated with high risk, whereas bears that were later killed selected more strongly for berries and less against risk prior to the hunting season (H3). To evaluate our hypotheses, we used resource selection functions to contrast bear GPS relocation data (N = 3 5, 2012-2015) and random positions within the bears home range with generalized linear mixed effect models against two focal variables: a map predicting bilberry occurrence and a map predicting human-induced mortality risk. We found that bears selected for areas with a high probability of bilberry occurrence (supporting H1), but avoided these areas if they were associated with and high risk of hunting mortality (supporting H2). The killed and surviving bears did not differ in their selection for bilberries, hut they did differ in their selection against risk (partially supporting H3). Surviving bears strongly avoided high risk areas, whereas killed hears responded less to risk and selected for high-risk areas with a low probability of bilberry occurrence. This suggests that killed bears selected for other food sources than berries in high risk areas, which exposed them to human hunters. We conclude that bears respond to a landscape of fear during the berry season and that different foraging strategies may have a direct impact on individual mortality during the hunting season. (C) 2018 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

Keywords

Brown bears; Bilberries; Foraging behavior; Human induced mortality; Hunting; Landscape of fear; Ursus arctos; Vaccinium myrtillus

Published in

Basic and Applied Ecology
2019, Volume: 35, pages: 18-27
Publisher: ELSEVIER GMBH

SLU Authors

• Domevscik, Matej

  • Unit for Field-based Forest Research, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology
Fish and Wildlife Management


Publication identifier

DOI: https://doi.org/10.1016/j.baae.2018.12.001

Permanent link to this page (URI)

https://res.slu.se/id/publ/99323