Habitat security and diets for recovery of Alberta grizzlies: lessons from coastal BC, Alaska and Yellowstone

Brown bears (Ursus arctos) in North America vary widely in their densities from a maximum of 550 bears /1000 km2 in coastal Alaska to less than 5 bears /1000 km2 for mountain bears in the north; this variation has been attributed to differences in food base. The impacts of security and perceived risk on the exploitation of energy rich environments also have significant impacts on demographic rates within populations. Increasing the energy density of habitat has been identified as an important step in the restoration and maintenance of small brown bear populations in Europe and this is equally applicable to bear populations at risk in North America. Where bears persist at high densities they are in productive ecosystems, where protection has been of low productivity land populations which survive are marginal. Drawing on examples from Yellowstone, coastal British Columbia and Alaska we will present the case for using areas of enhanced habit security and energy density as source populations within a source-sink model of conservation of a species at the edge of its current range to halt the retreat of bears in Alberta