MOVEMENTS AND HABITAT SELECTION OF SHIRAS MOOSE (ALCES ALCES SHIRASI) IN COLORADO

Abstract

From December 1991, through November 1995, we recorded 3,897 locations of 66 radio-collared moose (Alces alces shirasi) (25 males and 41 females) in northcentral Colorado, to determine seasonal movements and selection of habitat. Few significant differences (P <0.05) were found between sex or age categories in median size of seasonal minimum convex polygon (MCP) areas, or in median distances moved between seasonal median activity centers (MACs), because movement depended mainly upon characteristics of individual animals. However, subadult and adult males used larger seasonal MCP areas than females, and adults used larger seasonal MCP areas than subadults. Sixty-two percent of subadult males and 17% of subadult, females dispersed from natal areas at distances ranging from 13 to 120 km. Moose >2 years old, of both sexes occupied annual home ranges that usually included several smaller areas which the animal used seasonally. Winter MCP areas usually included lower elevations than spring, summer, and autumn MCPS suggesting most moose migrated to higher elevations in other seasons. The only significant difference(P < 0.05) between sexes in proportional use of habitat types during seasons of the year was in lodgepole pine habitat in winter. Willow (Salix spp.) Was the most commonly selected habitat by moose in all seasons, and lodgepole pine (Pinus contorta) was second. Other habitat types used by moose were aspen (Populus tremuloides), spruce-fir (Picea engelmannii - Abies lasiocarpa), and grass meadow. Locations of radio-collared moose in lodgepole pine or spruce-fir usually were near willow habitat. We infer that willow habitat in riparian areas is important to maintain moose populations and should be protected from influences that could reduce its value to moose. During logging operations strips of uncut, mature timber should be maintained within 250 m of willow bottoms and clearcutting patterns should be designed to produce a mosaic of relatively large patches (> 0.7 km²) of uncut, mature timber. We suggest that no point in a clear cut be more than 100 m from adequate hiding cover.