Moose (Alces alces), are the largest living member of the deer family (Cervidae). Cows may weigh up to 350 kg and bulls may reach 600 kg. Moose have a black coat; long, stiltlike legs for wading through deep snow; a humped back; and a long face with an overhanging upper lip, large ears and a dewlap of skin (bell) hanging from the throat.
Distribution and Habitat
Moose inhabit the boreal forest from Newfoundland (introduced) and the Québec-Labrador Peninsula, through Nova Scotia and New Brunswick, west to British Columbia and north to the Arctic Ocean in Alaska. Called elk in Europe, they range from northern Asia to Scandinavia.
Bulls have long, horizontally spreading, palmate (flat handlike lobes) antlers, which begin to grow in April. Antlers remain velvet-covered until August and early September when they are used for fighting during the breeding season, September and October, and are shed December to February.
Reproduction and Development
In breeding season, cows are vocal; hunters can attract bulls by imitating the female call. Females can breed at 16-17 months and reproduce as long as they live, up to 18-20 years of age. Calves are born in late May and early June. Newborns weigh 11-16 kg are reddish-brown and are cached in concealing forest cover where the females remain nearby foraging prepared to defend her calf.
Moose browse birch, aspen, and willow twigs and leaves; and in winter the needles of balsam fir. They seek new regeneration in logged or burned habitats. Moose frequent lakes to eat aquatic vegetation, at times submerging completely.
In the fall after leaves fall moose shift from their summer home ranges to winter home ranges seeking reduced snow depth under snow-laden canopies. Bedding in fluffy snow aids thermoregulation and the best thermal cover is dense conifers that guard against the heat sink on cold clear nights. The size of winter home ranges varies between geographical areas and habitats (extreme values 5 to 30 km2). Size varies inversely with plant biomass and/or quality of the forage, that is, the better the forage the smaller the home range. Small winter ranges minimize scent detection by wolves. Moose take advantage of forest obstructions in flight but at times stand and fight. Wolves commonly test the vigour and strength of moose and if they judge the animal will be very difficult to kill, often move on looking for a less fit individual.
Moose have a huge capacity for population growth. With good nutrition yearlings often conceive and twinning can be as high as 30-40%. Moose only need 25 calves for every 100 females at 12 months of age to maintain their numbers. The major predators are wolves and bears, and hunting is a major mortality factor. Starvation can occur (mostly calves) when numbers are high and excessive snow depths occur. Moose have a winter tick problem than can predispose them to predation. Wolves kill mostly calves and adults older than 8 years. Longer growing seasons in the boreal forest and Arctic due to climate change has allowed moose populations to prosper and extend their ranges north.