Drivers of Arctic female grizzly movement-related habitat use from den emergence to green-up

Arctic female grizzly bears (Ursus arctos) with cubs face a challenging period following den emergence to find quality resources when risk of infanticide is high and food is scarce. We used global positioning system (GPS) telemetry data grouped by reproductive state (solitary, females with cubs <1 yr old, females with cubs ≥1 yr old) to examine trade-offs between access to security cover and access to food during the hypophagic period from 5 June to 4 August (2003–2006), in the Mackenzie Delta region, Northwest Territories, in the Canadian Arctic. We used step-selection functions to model habitat selection with parameters for land cover, land cover diversity, and topography measured along the step and at the end. We fit the models for each individual and used 2-stage model-averaging to determine the top model for describing landscape factors influencing movement. We found that while female movement rates (i.e., step length = m/4-hr location interval) differed with reproductive state, movement-related habitat selection was similar. Females with cubs <1 year old moved the least (x̄ step length = 700 m, 95% CI [655–745]) compared with females with cubs ≥1 year old (x̄ = 1,484 m [1,415–1,553], P < 0.001), and females without cubs (x̄ = 1,652 m [1,581–1,723], P < 0.001), who moved the most. Across all reproductive states, our results suggest that females prioritize security over food availability along movement paths. Our results contribute to a better understanding of the behavioral decisions made by female grizzly bears and provide insights into trade-offs between security and food resources, when resource availability is uncertain.