Moose are the largest members of the deer family and one of the largest land mammals in North America. Adults may stand as tall as 2.3 m high. Males are larger than females and possess elaborate, widened antlers that can measure up to 2 meters in total width, from tip to tip. These are the largest antlers carried by any mammal, worldwide. They are shed and re-grown annually. Males range from 2.5 to 3.2 meters in total length, females from 2.4 to 3.1 meters. Males weigh from 360 to 600 kg and females from 270 to 400 kg. Moose have thick, brown fur that ranges from light to almost black in color. Individual hairs are 15 to 25 cm long and hollow, resulting in excellent insulation. Moose are also distinguished by their long head with a long, flexible nose and upper lip. Moose have very long legs and a dewlap of skin on the throat. (Wilson and Ruff, 1999)
Moose are found throughout North America in the moist, cold forests of the north. They are found throughout Alaska, Canada, the northeastern United States and as far south as the Rocky Mountains in Colorado. They are generally found near streams or ponds where there are willows.
Moose generally live in forested areas where there is snow cover in the winter, and prefer moist conditions where there are lakes, ponds, and swamps. They are found in areas with snow cover up to 60 to 70 cm in depth during the winter, although deep, crusted snow makes them vulnerable to predation by wolves. Moose are limited to cool regions because of their large bodies, inability to sweat, and the heat produced by fermentation in their gut. They cannot tolerate temperatures that exceed 27 degrees Celsius for long. In summer moose seek shade and cool themselves in ponds and streams. (Wilson and Ruff, 1999)
Females attract males with their long, moaning vocalizations, which can be heard up to 3.2 km away. They also emit a powerful scent. Rival males compete for access to females during the breeding season. Males may simply assess which is larger, and the smaller bull retreats, or they may engage in battles that can become violent. (Franzmann, 1981)
Mating takes place in September and October. There is an eight month gestation period. Females give birth synchronously during late May and early June. Females generally produce single young, although twins are common. Young lack the spots that are characteristic of most offspring in cervids. Males and females are sexually mature at two years of age but full growth potential isn't reached until 4 or 5 years of age. At that age females are at their reproductive peak and males have the largest antlers. (Franzmann, 1981; Wilson and Ruff, 1999)
Young moose weigh 11 to 16 kg at birth and gain about 1 kg per day while they a re nursing. They can browse and follow their mother at 3 weeks of age and are completely weaned at five months. They stay with their mother for at least a year after birth, until the next young are born. (Franzmann, 1981; Wilson and Ruff, 1999)
Up to half of all moose die within their first year of life. Adult moose are in their prime from 5 to 12 years of age but begin to suffer from arthritis, dental diseases and wear, and other factors after about 8 years. Male moose also suffer as a result of male-male aggression associated with mating. Few bull moose survive longer than 15 years in the wild and the oldest recorded cow moose was 22 years old. (Wilson and Ruff, 1999)
Moose are active throughout the day with activity peaks during dawn and dusk. Moose are good swimmers, able to sustain a speed of 6 miles an hour. They move swiftly on land. Adults can run as fast as 56km/h (about 35 miles per hour). Moose mainly stay in the same general area, though some populations migrate between sites favorable at different times of the year. These migrations can exceed 300km in European populations.
Moose are solitary animals, although two individuals sometimes can be found feeding along the same stream. The strongest social bond is between the mother and the calf. Mothers are very protective of their calves, frequently charging people if they get too close and using their sharp hooves to strike at attackers. Moose gather in larger groups during the mating season in alpine and tundra habitats. (Wilson and Ruff, 1999)
Moose home ranges average 5 to 10 square kilometers. (Wilson and Ruff, 1999)
Moose have poor sight but their hearing and sense of smell are excellent. Their large ears can be rotated 180 degrees and their keen noses find food below deep snow. Their vision seems to serve them best to detect moving objects.
Moose eat twigs, bark, roots and the shoots of woody plants, especially willows and aspens. In the warm months, moose feed on water plants, water lilies, pondweed, horsetails, bladderworts, and bur-reed. In winter, they browse on conifers, such as balsam fir, and eat their needle-like leaves. They require 20 kg of food per day. Their stomachs, when full, can weigh up to 65 kg. Most of a moose's time is spent eating.
Because of their large size most predators cannot prey on moose when they are healthy adults. Most moose are preyed on as young or when they are ill or elderly. Their main predators are large carnivores such as wolves, grizzly bears, and black bears. Humans limit populations in many areas. Moose are also able to aggressively defend themselves and their young with their large antlers and sharp hooves. (Wilson and Ruff, 1999)
Moose have dramatic effects on the composition of plant communities through their browsing.
Moose are affected by several diseases and parasites. "Moose disease", fatal to moose, is caused by a brainworm which most commonly infects white-tailed deer. Moose can become severely infested with winter ticks and death can sometimes result in winter as a result of blood loss and nutritional stress. (Wilson and Ruff, 1999)
Moose eat young pine and spruce trees, so can damage reforestation efforts. Also, the cost of moose and automobile impacts can be very high in both injuries and property damage.
Moose are hunted for meat and for sport and are the focus of some ecotourism activities.
In some areas, moose populations have been greatly reduced by human hunting and habitat destruction. However, in the eastern United States moose populations have been expanding in recent years and moose populations introduced in Michigan and Colorado are doing well. Moose are commonly involved in car accidents and often wander into residential areas in their search for food. Moose are not listed as threatened or endangered on the national or global levels, but they are a species of special concern in Michigan. (Wilson and Ruff, 1999)
Tanya Dewey (author, editor), Animal Diversity Web.
Anne Bartalucci (author), University of Michigan-Ann Arbor, Bret Weinstein (author), University of Michigan-Ann Arbor.
Gelder, Richard. 1928. Mammals of the National Parks. Johns Hopkins University Press, Baltimore.
Stidworthy, John. 1988. The Large Plant-Eaters. Equinox Limited, Oxford.
Walker's Mammals of the World, fifth edition; Nowak, R. ed.; 1991; Johns Hopkins University Press.
Franzmann, A. 1981. Moose (Alces alces). Mammalian Species, 154: 1-7.
Wilson, D., S. Ruff. 1999. The Smithsonian Book of North American Mammals. Washington: Smithsonian Institution Press.