Alces alces
Eurasian elk
(Also: Eurasian moose)

Alces alces, commonly called moose in North America and Eurasian elk in Europe, have a circumpolar distribution in the boreal forests of the Northern Hemisphere. (Eurasian elk should not be confused with North American elk, Cervus canadensis, which are a different species.) In Eurasia, Alces alces have a range on the west from Scandinavia, Poland and southern Czech Republic to Siberia (Russia) in the east. Its southern range extends to Ukraine, northern Kazakhstan, northern China and northern Mongolia. In North America, moose are found throughout much of Alaska and Canada and just south of the border between the contiguous United States and Canada, but extend farther southward down the Rocky Mountains to Utah and Colorado. Factors that likely limit their northern distribution are sufficient forage and snow depths greater than 70 cm for long periods. Warm climates that have temperatures above 27 C for long periods likely limit their southern distribution. (Grubb, 2005; Karns, 2007; Kelsall and Tefler, 1974)

Moose can be found in a range of habitats in the cold, northern regions of the globe that have seasonal snow cover. They inhabit the taiga and temperate forest biomes, including the tundra-subalpine zone. Forest types include boreal, broadleaf and mixed (coniferous-deciduous). Within these forests, they prefer the early successional stage, where forage is in abundance due to disturbance. Fire, logging, flooding, or glacial action greatly increase the quality and quantity of forage for moose and, ultimately, moose density. Besides forested habitats, moose will seek out areas near water, such as ponds, lakes, rivers and swamps, which also have a concentration of their favorite foods. Their large bodies, inability to sweat, and the heat produced by fermentation in their guts mean they cannot tolerate temperatures exceeding 27 degrees Celsius for long. (Bowyer, Van Ballenberghe, and Kie, 2003; Peek, 2007)

Moose are the largest species in the deer family, having long, slender legs that support a massive body, while a short, thick neck and humped shoulders that support a large head. This horse-size species can be as tall as 2.3 m at the shoulders with long ears (250 mm) and an inconspicuous tail (80 to 120 mm). One of the most distinctive features of this species is its long, bulbous, drooping muzzle. The upper lip overhangs the lower lip and between its nostrils is a triangular patch of bare skin. Under the neck hangs a flap of furred skin called the bell, which may or may not be present in females. With no upper incisors or canines, moose must nip off plants between a bony upper palate and their lower incisors. They have a dental formula of I 0/3, C 0/1, P 3/3, M 3/3 = 32. (Bubenik, 2007; Wilson and Ruff, 1999)

Males are distinguished by carrying the largest antlers of any mammal, which can weigh as much as 35 kg in North American moose. Antlers are grown in the spring and shed in the winter each year. The widest antler spread recorded is 2048 mm. Antlers of North American moose are palmate, having a main palm and brow palm in a butterfly configuration. A cervine-shape, without palmation, is more common in European moose (Alces alces alces) and Manchurian moose (A. a. cameloides). (Bubenik, 2007; Engan, 2001; Novak, 1999)

Moose are sexually dimorphic, with males being more than 40% heavier than females. Live weights of males range from 360 to 600 kg with lengths from 2.4 to 3.1 m. Females range from 270 to 400 kg with lengths 2.3 to 3.0 m. The largest subspecies of moose, Alces alces gigas, occurs in Alaska with a maximum weight of 771 kg for a male and 573 kg for a female. (Bowyer, Van Ballenberghe, and Kie, 2003; Bubenik, 2007)

Pelage is generally dark, black to brown or grayish brown, with the lower legs being lighter. An all-white color phase is rare. Their underfur and long guard hairs provide excellent insulation from cold. Young have a reddish brown pelage and are not spotted like other young in the deer family. Individual hairs are 15 to 25 cm long and hollow, resulting in excellent insulation. (Novak, 1999)

Many calves, as much as 50% or more, do not live beyond their first six weeks of life due to predation by bears and wolves. Once they reach adulthood, their chances of survival are high. Adult females have an average survival of 95%. Male survival is more variable due to hunting and male-male competition. 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. Few moose live past 15 years in the wild, although one cow was recorded to have lived to the age of 22. Peak reproductive age in females is 4 to 12 years of age and 4 to 8 years in males. (Bowyer, Van Ballenberghe, and Kie, 2003; Gaillard, Festa-Bianchet, and Yoccoz, 1998; Wilson and Ruff, 1999)

Moose are the least social species among cervids, remaining fairly solitary except during the mating season. They are not territorial. Outside of the rutting period, males and females are sexually segregated: males and females are separated spatially, temporally, and/or by habitat. It has been hypothesized that this is due to the differences in nutritional needs of the sexes due to body size differences. Also, cows with calves at heel seclude themselves from conspecifics to reduce the risk of being singled out by predators. Moose are crepuscular by nature, being most active at sunrise and sunset. Despite their ungainly appearance, moose are able to run silently through dense forests. Maximum speeds have been clocked at 56 km/hr and sustained speeds at 9.6 km/hr. Moose are also strong swimmers, being known to swim up to 20 km or up to 9.5 km per hour. Most of their time centers around feeding. The daily pattern is traveling to a new site to feed, avoiding predators, browsing on plants, standing, and lying down for the rumination of their food. 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. (Boyer, 2004; Bubenik, 2007; Wilson and Ruff, 1999)

Home Range

Home range size of moose varies between 3.6 to 92 km2. During their first year of life, young moose occupy the same home range as their mother and do not establish their own home range until the age of two. Home range size of males tend to be larger than females. Some moose migrate seasonally, up to 179 km in North America and 300 km in northeastern Europe. (Hundertmark, 2007; LeResche, 1974; Pulliainen, 1974)

Moose are not as vocal as other members of the deer family, such as elk (Cervus elaphus). Most of their vocalizations occur during the rut. Females make a long, quavering moaning call when in estrus, which attracts males and can be heard up to 3.2 km away. Males make a grunt to court females or challenge other bulls. Both sexes are capable of making a loud, guttural “roaring” sound as a threat. Moose will also communicate chemically by scent-marking trees. They strip trees and shrubs of their bark and rub their foreheads and preorbital glands into the bare spot to advertise their presence to the opposite sex. Moose are not known to have good eye sight. Confirmation of this is not available due to a lack of studies, although it is known that they depend less on sight than their sense of hearing or smell. Moose have very acute hearing due in part to the large external surface area of their ears. Their ears are capable of rotating independently, giving them stereophonic hearing. Their sense of smell is exceptional due to the large surface area of their nasal cavities, which are lined with millions of sent-smelling cells. (Bowyer, Van Ballenberghe, and Kie, 2003; Bubenik, 2007; Franzmann, 1981)

The word “moose” comes from the Native American tribe, the Algonquins, which means “twig eater” in their language. It is an appropriate name because moose primarily browse upon the stems and twigs of woody plants in the winter and the leaves and shoots of deciduous plants in the summer. For moose in Poland, 87% of their diet consisted of trees and shrubs with the most important species being pine (Pinus silvestris), which represented 52% of their diet. In North America, moose have been observed to consume as many as 221 plant species and genera, and in Russia 355, although only a select few comprise a significant portion of their diet. Willows (Salix spp.) are the most preferred forage where available. In interior Alaska willows accounted for 94% of the biomass consumed in the winter. Other species that are consumed are paper birch (Betula papyrifera), quaking aspen (Populus tremuloides), and balsam fir (Abies balsamea). Moose also consume aquatic vegetation during the summer because it is highly digestible and abundant in some areas. An adult requires about 20 kg food per day. (Bowyer, Van Ballenberghe, and Kie, 2003; Franzmann, 1981; Renecker and Schwartz, 2007)

Wolves, brown or grizzly bears, black bears, and cougars are major predators of moose, and to a lesser extent coyotes and Amur tigers. Major predators can have such an impact on moose populations that they can slow their population growth and hold them below the carrying capacity of the habitat. Whether or not predators can hold (regulate) a moose population at an equilibrium point is controversial. Predation by bears tends to be the highest in the spring when calves are the most vulnerable. Predation by wolves is higher in the winter when snow depths are high enough to impede the movement of moose. Moose aggressively defend themselves and their young with their robust antlers and sharp hooves. (Ballard and Van Ballenberghe, 2007; Bowyer, Van Ballenberghe, and Kie, 2003; Franzmann, 2000; Matyushkin et al., 1996)

Moose can have a significant impact on ecosystems because of their daily activities of feeding, trampling, defecating, and urinating. One researcher estimated that the Swedish moose population contributed 300,000 metric tons of feces each year to the land. This equals about 5,600 tons of nitrogen, which is essential for plant growth. Moose can affect the rate of nutrient cycling, floral composition, rate of forest succession, and biological diversity of a forest. For this reason, they are considered to be a keystone species. (Kie, Bowyer, and Stewart, 2003; Kielland and Bryant, 1998; Molvar, Bowyer, and Van Ballenberghe, 1993; Persson, Danell, and Bergstrom, 2000)

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)

Vehicle collisions with moose are a serious problem in North America and Europe. In North America, nearly 3,000 occur each year. In Sweden alone, 4,500 occur per year on average, as well as 10 to 15 human fatalities. Beyond the incalculable cost in terms of human life, moose collisions cause significant property damage, escalate insurance premiums, can cause a local moose population to decline and reduce recreational opportunities. Moose can also be a pest to agriculture and forestry in some areas. Moose foraging can inhibit the growth of young trees. In Russia, damage to the forestry industry was estimated in millions of rubles, during the 1950's. (Child, 2007; Kuznetsov, 2002; Seiler, 2005)

Moose are hunted throughout much of their range and provide millions of pounds in meat to humans each year. In 1983, 152,000 moose were harvested in Sweden, representing 14% of the total meat consumption of the country. Moose hunting also generates a considerable amount of money to local economies. Moose hunters contribute $31 million annually to Alaska’s economy and $50 million to Canada’s. Moose also draw many tourists for wildlife viewing opportunities. Moose milk is harvested from captive moose in some areas, including Russia and Sweden. (Bowyer, Van Ballenberghe, and Kie, 2003; Novak, 1999; Regelin and Franzmann, 1998)

IUCN lists moose as a species of “Least Concern” because a majority of populations are expanding and extremely abundant despite heavy hunting pressure in parts of their range. The Eurasian populations are estimated to be 1.5 million individuals, one-third of which consists of the European populations. In 2002, populations of the United States and Canada were estimated at 1,000,000. Some exceptions to this favorable assessment are moose in Manchuria and Mongolia (A. a. cameloides), which are scarce, and a population in Nova Scotia (A. a. americana), which Canada has deemed endangered. (Geist, Ferguson, and Rachlow, 2008; Henttonen et al., 2008; Novak, 1999; Timmermann, 2003)

Alces, which has been traditionally classified as a monotypic genus, has been recently divided into two species by some researchers: the European species, Alces alces, and the North American species, Alces americanus. Such a division has caused confusion and does not represent the latest genetic research. The division of moose into European and North American species was believed to be supported by morphological differences and evidence that European moose have 68 chromosomes and North American moose have 70. It is now known that moose in Central Asia (Yakutia) also have 70 chromosomes and share mitochondrial DNA halotypes with European and North American moose. Furthermore, moose exhibit low variability in mitochondrial DNA worldwide and have relatively low overall genetic diversity compared to other mammals. It is more likely that all extant lineages of moose originated from Central Asia within the last 60,000 years, supporting a single species hypothesis rather than a two or three species hypothesis. (Grubb, 2005; Hundertmark and Bowyer, 2004; Schwartz et al., 2002)