Habitat condition and the nutritional quality of seasonal forage and diets: Demographic implications for a declining moose population in northwest Wyoming, USA

Recent research suggested that habitat quality was likely limiting Jackson moose population growth. Thus, we evaluated seasonal browse condition and the quality of forage and diets, and monitored numerous demographic rates for this population. Winter range was more consistently and intensely browsed than summer range. Forage and diet quality was fairly homogeneous and of lower quality in winter than summer. Within summer, moose forages were of lower quality in burned compared with non-burned habitats. Despite selective foraging, the nutritional quality of diets resembled that of the habitat. Habitat-specific demographic rates were typically lower in burned compared with non-burned habitats. Overall the population is declining, however, habitat-specific population models suggest the portion of the population using burns is declining more rapidly than in non-burned habitats. Study findings suggest that wildfire on the summer ranges of these migratory moose is partially responsible for the observed population declines to present.