Brown bear (Ursus arctos) den site concealment in relation to human activity in Scandinavia

• Main Author: Sahlén, Ellinor
• Format: Other/Unknown Material
• Language: English; Swedish
• Published: SLU/Dept. of Wildlife, Fish and Environmental Studies 2009
• Subjects: brown bear; den site; denning habitat; habitat; cover; concealment; rugged terrain; human activity; infrastructure; sighting distance; villages; roads; Ursus arctos
• Online Access: https://stud.epsilon.slu.se/550/

As a hibernating species, the brown bear spend most of the winter months in a den as a strategy to avoid unfavorable conditions. The denning period is a vulnerable time for bears, making them unable to flee disturbances without losing valuable amounts of energy. Brown bears' wariness of humans and avoidance of anthropogenic disturbance often steer denning bears away from human infrastructure, and bears thereby avoid possible disturbance and its associated energetic costs. This study was carried out to test the hypothesis that bears denning closer to infrastructure select more covered den sites to compensate for the close distance. Dens from 32 individuals were visited and analyzed in terms of sighting distance (a measurement for den horizontal cover) and habitat ruggedness, in relation to distances to infrastructure. This study showed that bears tended to have more concealed dens and/or dens situated in more rugged terrain closer to roads and settlements with the highest human activity. Expanding human infrastructure might affect bear categories differently, since younger bears were shown to den closer to human activity areas than older bears. Close distance to human activity might therefore alter bears’ natural behavior evolved to endure unfavorable conditions during winter. Undeveloped forest regions are important to decrease anthropogenic effects on bear denning behavior, and presumably also for the spatial distribution concerning different bear categories (e.g. age classes). Som en övervintrande art så spenderar brunbjörnar de flesta av vintermånaderna i iden som en strategi för att undvika ogynnsamma förhållanden. Idesperioden är en känslig tid för björnar eftersom de då inte kan undvika störningar utan att därmed förlora värdefull energi. Brunbjörnars undvikande av mänskliga störningar driver björnar och deras idesområden bort från mänsklig infrastruktur och på detta vis undviker björnar möjliga störningar och de energimässiga kostnader som är förenade med dessa. Denna studie utfördes för att testa ...