Habitat composition and spatial response of white-tailed deer to forestry treatments in moose range, Grand Portage Indian Reservation, Minnesota

Abstract

Moose (Alces alces L.) have long been an important subsistence species are of great cultural value to the Ojibwe peoples. White-tailed deer (Odocoileus virginianus Z.) have been implicated in negatively impacting ecosystems as distribution shifts northward with changes in climate and land cover. In response, moose populations have shown declines due to transmission of brainworm (Parelaphostrongylus tenuis D.) where ranges overlap spatially with deer. Brainworm was identified as a primary factor in moose mortalities in the Grand Portage Indian Reservation of northeastern Minnesota. Spatial data was collected over a nine-year period from GPS collared moose and deer captured within the reservation. Home and seasonal ranges were delineated from GPS locations using kernel density estimation (KDE). Outputs were evaluated in ArcMap to determine spatial and temporal overlap, habitat composition of moose relative to deer, and responses to forest harvest and silvicultural treatments. Hypotheses tested include 1) white-tailed deer habitats are different from those of moose, 2) deer range overlaps significantly with moose range during the summer months, 3) forest management treatments aimed at benefitting moose, do not encourage deer use, while 4) forest management treatments made in deer range are utilized by deer. Results for deer show larger ranges and seasonal movements, unlike moose. Deer habitat use differs from that of moose with the exception of cover types that are limiting or support browse communities that are used similarly by both species. Both moose and deer utilize all forestry treatments showing the same order of intensity in use, with the exception of Prescribed Fire treatments that are concentrated in core deer range and rarely visited by moose because they are not in moose range.