WINTER HABITAT SELECTION OF MOOSE IN MAINE AND RUMINATIONS ON THE IMPACT OF CHANGING WEATHER CONDITIONS

Abstract

Winter habitat use by moose (Alces alces) in response to climate change may reflect shifts in biotic and abiotic stressors that pose both environmental challenges and opportunities. Snow depth, temperature, winter length, and forest composition influence moose mobility, habitat use, and access to forage and cover resources. We analyzed habitat selection in winter home ranges of adult female moose (n = 96) over the course of six winters (2014–2019) to explore the influence of winter weather and forest composition on landscape and habitat use. Second order (home range) resource selection functions were estimated using generalized linear mixed models. Moose selected most strongly for forest habitat, specifically evergreen and mixed forests, which had similar strength of selection and represented ~50% of home ranges. The models identified a slight positive association with regenerating forest, although high levels of variance indicated a weak relationship. Contrary to our prediction, we did not detect any influence of weather conditions on winter habitat selection. Maine’s mosaic of forest types and commercial forestry seemingly provide adequate food and cover resources for moose regardless of winter conditions, with the three habitat types selected for representing ~70% of home ranges. Due to the coarse resolution of the data we analyzed, more specific data on forest structure such as stand age, canopy, and forage species may be required to identify finer relationships in habitat use and specific resource requirements during winter. It is possible that other factors associated with climate change, such as increases in deer (Odocoileus virginianus) populations, parasites, and disease will have greater influence on moose than habitat per se. However, because these potential influences are indirectly related to habitat use by moose, further research is warranted to best understand the multiple factors and relationships affecting winter habitat use.