The Effects of Edges on Grizzly Bear Habitat Selection

Proceedings of Spatial Knowledge and Information – Canada (SKI-Canada) 2011, March 3-6 in Fernie, BC, Canada

Benjamin P. Stewart, Trisalyn Nelson, Michael A. Wulder, Scott E. Nielsen, Nicholas C. Coops, and Gordon Stenhouse

“Understanding grizzly bear (Ursus arctos) habitat selection is critical for managing threatened populations. The goal of this paper is to develop a better understanding of grizzly bear habitat use through a comparison of grizzly bear location data with landscape edge inventories. We utilized GPS telemetry data from 26 grizzly bears from 2005-2009 in the foothills of the Rocky Mountains in west-central Alberta. The locations were compared to a series of landscape transitions extracted from landcover data, and linear features, such as streams, roads, and pipelines. Results show variation between seasons and sexes in edge distance, selection, and density. Wetland edges comprise a small proportion of the study area (< 2%) but females select edges of this type up to 7% of the time, with little variation between seasons. Roads are selected for by females, but avoided by males, and hydrocarbon pipelines show similar results to roads, indicating these are also important grizzly bear edges. Seasonal differences indicate that females and males select for edges more in the fall, due to changes in feeding and security, or as a result of contracting home range following the mating season. These results indicate that while managing for anthropogenic disturbances in grizzly bear habitat is of utmost concern, understanding bears’ reactions to natural transitions can provide new management opportunities not related to resource extraction activities. Specific focus should be paid to maintaining wetlands, as these areas are selected by grizzly bears, but they comprise a very small part of the study area.”