Abstract

Seasonal movements, habitat selection, physiological health, and demography of Shiras moose (Alces alces shirasi) were studied in the Jackson Valley of northwest Wyoming. Moose congregated on low-elevation ranges during winter and migrated to more dispersed, mid-elevation ranges during summer. Moose selected winter habitat dominated by deciduous shrubs, whereas they selected summer habitat that was more variable. Blood parameters indicated that moose were in moderate physical condition. Ultrasonic rump fat measurements were relatively high, but there were indications of nutritional deficiencies. Diseases and parasites appeared to have minimal population-level effects. Population modeling suggested that the moose population was more likely to be declining than stable or increasing and the population growth rate was influenced primarily by late-winter and early-spring adult female mortality. Pregnancy rates were high, but calf production was relatively low. Neonate and annual calf survival were relatively high. Habitat quality appeared to be the primary factor limiting population growth while the effects of predation appeared to be less important.