Risk of mortality and maternal status are key determinants of the dynamic use of cover by moose in a landscape characterized by forest harvesting.

Abstract

Human-caused landscape disturbance is one of the most widespread threats to wildlife. Forest harvesting reduces canopy closure, an important component of habitat that allows ungulates to mitigate warm temperatures and deep snow. These pressures may be exacerbated by the warming temperatures and increased snowfall associated with climate change. Also, linear features that result from human activities increase the movement rate and efficiency of predators. We used LiDAR and GPS-collar data to test three hypotheses that explained the use of forest cover by female moose (Alces americanus) in a landscape characterized by extensive forest harvest; the Thermal Stress, Locomotion, and Direct Mortality Hypotheses. The risk of direct mortality by predation and during the licensed hunting season was the primary factor influencing the use of horizontal and vertical cover by moose. Moose used less horizontal cover when accompanied by a neonate and in areas with greater risk of predation by wolves. Maternal status of moose mediated their use of vertical cover to avoid predation. Moose also used more horizontal and vertical cover during peak hunting season and in the spring and summer. Our results suggest that the use of forest type and cover by moose differs, from open to closed, depending on the type of threat and reproductive status. When managing moose habitat, we recommend maintaining forests that vary in structure and cover, attributes often associated with a spatially adjacent mix of young and old forest.