SURVIVAL, REPRODUCTION, AND MOVEMENTS OF MOOSE IN THE WESTERN UPPER PENINSULA OF MICHIGAN

Abstract

Moose were extirpated from the Lower Peninsula of Michigan by the late 1800s. Although it is not clear if moose were extirpated from the Upper Peninsula (UP), the population was at the very least, reduced to a low level by ca 1900. Attempts to re-establish a population of moose in the UP during the mid-1930s failed. The Michigan Department of Natural Resources made a second attempt to reestablish moose by translocating animals from Canada to the western UP in 1985 and 1987. Based on optimistic estimates of survival and reproductive rates and habitat surveys, a population of 1,000 moose was expected by the year 2000. However, aerial surveys conducted in the winters of 1996 and 1997 produced population size estimates that were well below 1,000. To determine possible reasons for the slower than expected population growth, 84 moose were outfitted with radio-collars in the winters of 1999-2001. The survival, reproduction, and movements of these moose and 12 others radio-collared in 1995 were monitored from January 1999-June 2001. Overall, 1999-2001 pregnancy rates averaged 75%. Annual adult survival rate (0.88) was higher than yearling survival rate (0.82). First-year calf survival rate (0.71) was high, relative to highly preyed on populations. Annually, approximately 6% of radio-collared moose, primarily yearlings, dispersed out of the study area. The size of moose home ranges was typical of those found in the deciduous/coniferous ecotone of the upper Great Lakes region. Migratory adult moose had larger annual home ranges than did non migratory adult moose. Low productivity appears to be the likely cause of the slower than predicted population growth. Data from this study can be utilized to facilitate management of moose in the upper Great Lakes region.