Resource heterogeneity & grizzly 'foraging' behaviour
Photo: Scott Nielsen - buffaloberry shrub in a forest opening
Spatial heterogeneity of buffaloberry (Shepherdia canadensis) in relation to forest canopy patterns and its importance for grizzly bear (Ursus arctos) resource selection
Hinton, Alberta
Principle Investigator
Associate Professor & Alberta Biodiversity Conservation Chair
Graduate Student
Research Assistant
Status: Completed,

Catherine studied the spatial heterogeneity of Canada buffaloberry (Shepherdia canadensis), a key fruit resource for grizzly bears (Ursus arctos) in Alberta, and its role in bear habitat selection. She applied a fractal analysis approach to examine relationships between the forest overstory and buffaloberry shrubs in the understory, and found that evergreen canopy heterogeneity significantly predicted buffaloberry heterogeneity, while deciduous canopy had no effect. The influence of canopy patterns on those of the understory also varied with spatial scale. She additionally used resource selection function (RSF) models to assess the importance of buffaloberry heterogeneity, represented by shrub abundance and variability in fruit density, for grizzly bear habitat use during the pre- and fruit ripening periods through a comparison of foraging strategies. Buffaloberry heterogeneity was the resource property that best explained habitat selection, which may relate to the generalist nature of grizzly bears and alludes to their broad level of spatial perception, or environmental “grain”. Catherine’s findings emphasize the need to consider both spatial scale and resource heterogeneity in analyses of animal habitat use to inform the conservation and management of wildlife species at risk.

Further details can be found in her M.Sc. thesis and Denny and Nielsen (2017).