Abstract

Topic: Movements and habitat use

Habitat selection by moose in northeast Minnesota, USA: a warming environment

Deahn Donner¹, Amanda McGraw², Michelle Carstensen³, Jessica Fowler⁴, Jacob Hurd⁴

USDA Forest Service, Northern Research Station, 5985 County Highway K, united states
Minnesota Department of Natural Resources, 1201 E Highway 2, Grand Rapids, Minnesota, United States
Minnesota Department of Natural Resources, 5463 West Broadway, Forest Lake, MN, United States
USDA Forest Service, Northern Research Station, 5985 Highway K, Rhinelander, WI, United States

Abstract
Moose populations in northeast Minnesota, USA, experienced a 60% reduction in the mid 2000s. The population has since stabilized but continues to face numerous challenges related to warming temperatures; individuals are experiencing thermal stress and potential increased contact with white-tailed deer that transmit fatal parasites. The projected loss of temperate-boreal forests to deciduous forests with warming climates may reduce options for thermal refuge. Understanding how moose make space-use decisions currently under challenging climate in the southern edge of their range is important for informing future forest management activities that could be implemented to lessen these challenges in the future. We used adult moose (n=161; 115 females, 46 males) location data from 2013 – 2018 to conduct a multi-grain resource selection function analysis that incorporates fine-grained habitat types and browse resources (quality and quantity of trees and shrubs <2.8-m tall). We quantified resource selection at multiple grains using buffers of increasing radius (100 – 2000 m including average step length) around telemetry and random locations to examine the scale at which moose selected each forest type, and the influence of edge and browse resources by season (winter, summer) and sex on selection. In winter, males and females selected areas with greater proportions of mixed woodlands (primarily aspen, birch), northern hardwoods (primarily maples, closed canopy), young mixed woodlands (< 5 m in height), and high quantities of highly preferred browse species at small grains (102 – 121 m buffers). In summer, males and females selected areas with greater proportions of mixed woodlands at the average step length grain (228 m females; 345 m males) followed by northern hardwoods at the smallest grain (100 m); browse resources did not have as great of an effect on space use as in the winter. For both sexes and seasons, moose selected for cedar swamps (thermal habitat) at larger grains, especially males in summer (1000 m). Results suggest heterogenous landscapes with thermal habitat at small- and large-grains are more preferred, but the effect of each habitat type varies by season. Forest managers can use this information to incorporate multiple scales in future habitat management plans.