Abstract

In Scandinavia, native brown bears (Ursus arctos) were reduced to about 130 animals, but are increasing (now over 2500) and are re-colonizing huge areas from which they have been absent for many decades. We evaluate den site selection of brown bears, because their effective management and conservation needs accurate information on specific habitat requirements. Furthermore, because previous studies suggest that disturbance by humans can affect both den site selection and den abandonment, we tested if roads of various sizes are important. In a study area of 20,700 km2, the vegetation types within a 500-m radius of 250 dens used from 1990 to 2000 in south-central Sweden were analyzed using a GIS. Compositional analysis tested if bears selected or avoided certain habitat types for denning. Bears showed distinct preferences in denning habitats; selecting for open canopy (Scots pine, Pinus sylvestris) forests and bogs with deciduous swamp forests, before closed canopy (older Norway spruce, Picea abies, and Scots pine) forests, young forest & clear cuts, mountain coniferous forests, and bogs. Denning bears avoided water, alpine mountain-birch forest, deciduous forest, peat, exposed bedrock and gravel pits. Bears denned more on lower altitudes, easterly aspects and steeper slopes than was available. Furthermore, bears avoided intermediate-size roads, likely because they are a major source of human disturbance, providing a combination of easy winter access (because they are plowed), and a relatively high traffic intensity. Major highways were not avoided (likely because these roads do not allow access to the forest), nor were minor forestry roads avoided (likely because they are not ploughed in winter, and thus do not allow access during the denning period). We suggest that as bears continue to re-occupy more areas, managers must consider the role of roads and human disturbance in decisions regarding the protection of habitats for bears

Published in

Title: Book of Abstracts of the International Union of Game Biologists XXVIII Congress, Uppsala 2007
Publisher: Sjöberg, K

Conference

International Union of Game Biologists XXVIII Congress

SLU Authors

• Ball, John

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Permanent link to this page (URI)

https://res.slu.se/id/publ/17360