Road Visibility Influences Habitat Selection by Grizzly Bears

bears on road

Article published in the Canadian Journal of Zoology. Citation and abstract only.

Abstract

Anthropogenic disturbances, including roads, are known to influence animal habitat selection and mortality. In this study, we consider the role of sensory perception in understanding why and how animals respond to disturbances. Our goal was to investigate the effect of visual perception (visibility) around roads on grizzly bear (Ursus arctos Ord, 1815) habitat selection and mortality in Alberta, Canada. We used detailed topographic and vegetation data from airborne Light Detection and Ranging (lidar) to estimate visibility around roads. We modelled habitat selection as a function of road visibility and environmental variables using GPS telemetry data from 39 grizzly bears and integrated step selection analysis (iSSA). Finally, we assessed mortality risk in visible areas by comparing habitat selection between grizzly bears that died and those that survived. We found that grizzly bears were less likely to select visible areas when moving slowly or resting, but more likely to select visible areas when traveling. We found that grizzly bears that survived selected for areas farther from roads than grizzly bears that died. However, no difference in selection for visible areas was observed. An exploratory analysis showed that grizzly bear mortalities commonly occurred in visible areas. Our findings highlight the importance of sensory perception in understanding animal behaviour.

Citation

Parsons, B. M., Coops N. C., Kearney S. P., Burton C., Nelson T. A., & Stenhouse G. B. 2020. Road visibility influences habitat selection by grizzly bears (Ursus arctos horribilis). Canadian Journal of Zoology. e-First. doi:10.1139/cjz-2020-0125