Species: Alces americanus

Depending on habitat, home range may be up to several thousand hectares (Lawson and Rodgers 1997). Population density has been reported as up to 1-3 per sq mile (= 11.6 per 10 sq km) (Peterson 1955), but 18-20 per 10 sq km in unhunted area in eastern Quebec (Crete 1989). May herd in winter. <br><br>Winter weather (snow accumulation) may strongly affect populations, even more so than wolf density (Mech et al. 1987); however, Messier (1991) found that competition for food, but not wolf predation and snow, had a regulatory impact on moose. Van Ballenberghie and Ballard (1994) found that in naturally regulated ecosystems predation by bears and wolves often is limiting and may be regulating under certain conditions. See also Messier (1994, Ecology 75:478-488) for population models of moose-wolf interactions. <br><br>Under favorable conditions, capable of large annual increases (20-25%) in population size; large populations may degrade habitat, resulting in population crash. See Albright and Keith (1987) for study of population dynamics of introduced population in Newfoundland (poor winter condition but high calf-survival [few predators]). <br><br>See Nudds (1990) for discussion of relation between white-tailed deer, moose, and meningeal (brain) worms. Brainworm may limit moose populations in areas where white-tailed deer are common. Deer are not negatively impacted by the brainworm, the larval stage of which is passed in deer feces. Snails, often inadvertently ingested by moose feeding on vegetation, are the intermnediate host for the worm. Deer, through worm-mediated impacts, commonly are believed to exclude moose and caribou from areas where deer occur; however, an analysis by Schmitz and Nudds (1994) concluded that moose may be able to coexist with deer, albeit at lower densities, even in the absence of habitat refuges from the disease. Whitlaw and Lankester (1994) found that the evidence that brainworm has caused moose declines is weak. <br><br>Moose may alter the structure and dynamics of boreal forest ecosystems. At Isle Royale, Michigan, moose browsing prevented saplings of preferred species from growing into the tree canopy, resulting in a forest with fewer canopy trees and a well-developed understory of shrubs and herbs; also, browsing may have caused an increase in spruce and a decrease in balsam fir (McInnes et al. 1992).