Alces alces - Moose

Picture and Reported Sightings

Skull Pictures:      
Dorsal        Ventral
Lateral     Mandible

Physical Description:

Moose are the largest cervids in the world. For adults their height to the shoulder ranges from 5 to 7 feet (1.75-2.25m) and their length from 8 to 10 feet (2.75-3.25m). Weight varies according to sex with males ranging from 900 to 1,400 pounds (400-640kg) and females ranging from 700 to 1,100 pounds (320-500kg) (WDNR 2003a).

Their coats range from dark brown to almost black in adults and red-brown in the young. The coat is made up of coarse hairs with numerous air cells which serve to keep the moose warm and provide insulation and buoyancy in the water (USFS 1981).

They can be recognized by their large size, high, humped shoulders, long legs, overhanging nose, short tail, and dewlap (USFS 1981). The dewlap hangs under the moose’s chin but its purpose is unknown (McDougall 1997).

Distribution in Wisconsin:

Current Distribution-

There are seven subspecies of moose worldwide, four which are found in North America. They are differentiated by size, color, palate shape, and geographic distribution. Alces alces andersoni ranges from northern Minnesota, Wisconsin, and Michigan into western Ontario to central British Columbia, and north to eastern Yukon Territory and the Northwest Territories (Snyder 1991).

The Wisconsin Department of Natural Resources estimated that Wisconsin’s moose population is about 20 to 40 animals, but varies quite a bit (WDNR 2003a). Currently they are found in the northern counties of Wisconsin. In 1987 Wisconsin DNR wildlife biologists compiled the number of moose in their districts according to observations reported to them (See Map 1). Since 1985, the Wisconsin moose population may have been affected by a reintroduction effort that occurred in the Upper Peninsula of Michigan in 1985 and 1987. Evidence of this is apparent in confirmed reports of moose in Vilas, Oneida, and Forest counties where no moose observations were confirmed prior to 1985 (Parker 1990).

The first moose calf birth in Wisconsin in more than a century was documented during the summer of 2002. The calf’s mother was originally collared by biologists from the Michigan DNR in 2000 and was recaptured in 2001 to be fitted with a radio collar that would allow Wisconsin biologists to track her movements while she was in Wisconsin. Wisconsin biologists have been tracking the cow during the spring and summer since the summer of 2001. Adrain Wydeven, a wildlife biologist with the Wisconsin DNR, said that during that time the moose had established a summer range in northern Forest County of Wisconsin, and then headed back to the Upper Peninsula of Michigan for the fall and winter. The calf was not spotted during the summer of 2002 but when the cow returned to Michigan in December a calf was spotted with her. The cow had spent the spring and summer in Wisconsin so it is most likely that the calf was born sometime while the cow was in Wisconsin. Wisconsin biologists have learned from her that moose can migrate between a summer range in Wisconsin and a winter range in Michigan, which other moose may be doing undetected (WDNR 2003a).

The first capture and radio-collaring of a moose in Wisconsin took place September 12th, 2003 in Forest County. The female moose was initially caught in Michigan during the winter of 2003 with her movements monitored by a Wisconsin DNR pilot (WDNR 2003c).

Historical Distribution-

Moose originally occurred across the northern half of Wisconsin in conifer-hardwoods forest, primarily north of latitude 44 degrees (Parker 1990). They were fairly common in these areas until the mid or late 1800’s, but were no longer found in the 1900’s. A few reports of sightings of moose occurred in the mid 1900s. This is thought to be from moose being moved from Isle Royale to the Michigan mainland and wandering across the border into Wisconsin. In the 1960’s moose began to be spotted in the northwestern portion of the state as the Minnesota population increased (WDNR 2003a). It is thought that during this time the Wisconsin moose population peaked at 40 to 50 animals (Parker 1990). According to the Wisconsin Department of Natural Resources, there have been more than 280 observations of moose reported over the last decade (WDNR 2003a).

In 1989 the Wisconsin DNR was directed by the State Legislature to investigate the likelihood of successfully reintroducing elk, moose, and caribou into the state. The publication, “Feasibility Assessment for the Reintroduction on North American Elk, Moose, and Caribou into Wisconsin” (Parker 1990) determined that elk reintroduction could succeed but moose or caribou would likely not (WDNR 2003b).

According to this report, there are two factors suggested that have limited the moose population in Wisconsin for the latter half of the 20th century. The first is the lack of suitable moose habitat. According to the report, suitable moose habitat would consist of 20% shrubs or other young cover types, 5-10% spruce/fir greater than 20 years old, and 5-10% wetlands (Parker 1990).

Elkie and Gluck (1997) show that if landscapes were managed to imitate the structure of natural burns, moose density could increase. This could be done with progressive clearcutting. Their results show that progressive clearcutting created higher moose densities and that moose densities did not change with modified cutting with smaller clearcut blocks (Elkie et al 1997).

Moose survival is threatened in areas where deer densities exceed 10 deer/mile2, and this density is exceeded throughout most of northern Wisconsin. One reason their survival is threatened in this situation is due to the presence of Parelaphostrongylus tenuis, or brainworm which is carried by white-tailed deer. This parasite has proved to cause high mortality in moose populations. In 1990, the occurrence of brainworm in white-tailed deer in northern Wisconsin was believed to be between 40% and 70%, which would most likely cause moose mortality (Parker 1990).   

Ontogeny and Reproduction:

Moose reach puberty at 1.5 years of age (USFS 1981). Females may breed at this time but most males won’t be competitors for females until age 3 or 4 (McDougall 1997). Their life span is approximately 8 years in length (Anonymous 1981). Except for mating season the two sexes do not intermix (McDougall 1997).

Moose rut or the breeding season begins in mid-September and continues through October (USFS 1981). During this time the bulls are at their peak size and strength. Moose are polygamous with the bull competing for one female at a time but mating with several others throughout the season. The dominant bulls will drive the younger bulls away and fight among themselves for the females. Threat displays are usually enough to drive one away but battles do occur. The purpose is to lock antlers with the opponent and force his head to the ground which in turn will lead to the subdued bull submitting to the dominant bull (USFS 1981).

The antlers are at their peak during this time from the moose rubbing up against trees to polish them. The antlers have been developing since April and will be shed in late November to January. The antler will be eaten by porcupines, squirrels, and other rodents for the calcium and other nutrients that they contain (McDougall 1997).

The cow gives birth to one or two young in spring after an 8 month gestation (Snyder 1991). Calves are lighter colored than the adults and cannot walk for the first few days. During this time they are very dependent on their mother’s milk. Within two or three weeks they begin to browse for food and are able to swim well. At five or six months the calves are weaned off of their mother’s milk and at one year old, before she gives birth again, they are driven off to fend for themselves (McDougall 1997).

Ecology and Behavior:

Moose are shy, solitary creatures but can reach speeds up to 35 miles per hour when approached by humans. They are good swimmers and swim up to 12 miles at a rate of 6 miles per hour. Mothers with calves of any age most likely will be aggressive and quick to anger while bull moose in rut have been known to charge anything they perceive as an intruder into their territory (McDougall 1997).

The moose’s vocalization sounds much like domestic cattle. Females communicate with calves using a low mooing sound, and calves respond with higher-pitched bleats. During rut, females communicate with males with a loud, cattle-like bawling to advertise their willingness to mate. This sound can be heard for a much greater distance than the female sounds to the calves. Bulls are silent most of the year except for rut. The bull’s bellow is a challenge to other bulls and also an invitation to the cows. They also have a low, huffing grunt during rut (McDougall 1997).

Moose are found throughout the boreal forests of North America (Snyder 1991). Moose may or may not migrate with the seasons due to terrain and food available. In the spring and summer they prefer low-lying areas, often with lakes and marshes. In the winter the moose prefer forested areas and move into dense conifer forests (McDougall 1997). Ideal winter habitat is composed of conifers taller than 18 feet with a canopy closure of 75 percent or greater (Snyder 1991). Moose can travel through snow depths up to 36 inches but become helpless in very deep snow. This factor enables them to live further north than the white-tailed deer (Parker 1990).

A diversity of habitats close together is important for moose (Parker 1990). These include cattail/sedge, young open shrub, young deciduous, young coniferous, semi-open conifer lowland, mature conifer, lowland, wetland shrub, shallow marsh, and deep marsh (Anonymous 1981). Ideal moose habitat found in northeastern Minnesota has been described as upland brush and/or poorly stocked aspen-birch which are less than 20 years old, with scattered areas of spruce and balsam and mature aspen-birch areas. Small amounts of lowland conifer stands are also present along with many lakes and ponds (Parker 1990). Moose are habitat forming and paths made by moose through the forest become used by many other species (USFS 1981).

Moose browse for food during the day but are most active at dawn and dusk. Compared to smaller herbivores, moose exhibit high consumption rates mostly achieved by taking bigger bites. However with seasonal changes moose display considerable adaptability within their diet (Renecker and Hudson 1986). From spring to fall moose mostly eat aquatic plants such as pondweed, water shield, pond lily, lotus, and marsh marigolds. Moose will feed along shorelines until winter snows and ice make it impossible. During the winter willow is a staple food but aspen, birch, dogwood, pine, cedar, and maple twigs and buds are eaten (McDougall 1997). By over browsing moose are capable of altering the species composition of plant communities and changing the overall character of the communities (Snyder 1991).

Their droppings appear in two basic seasonal forms. The pellets appear darker in the winter months and form a lumpy mass during the summer when more succulent food is eaten. The pellets can be up to 2 inches in length and have a sawdust or grainy appearance (USFS 1981). Estimation of daily defecation rates for moose can vary between 9.6 to 32.2 deposits. This variability makes defecation rates not a good source for population estimates but the droppings can be used to determine diet composition, food quality, baseline physiological profiles, and dry matter uptake (Joyal and Richard 1986).

Remarks:

The name moose comes from the Algonquin word which means “cuts or trims smooth.” This probably comes from the fact that moose are woodland browsers that use their flexible lips to strip twigs, leaves, and bark from shrubs and trees (Jones 1999).

Literature Cited:

Elkie, P. C., M. J. Gluck, R. S. Rempel, and A. R. Rodgers. 1997. Timber-management and natural-disturbance effects on moose habitat: landscape evaluation. Journal of Wildlife Management 61(2):517-524.

Jones, D. 1999. North American wildlife. Whitecap Books Ltd., Vancouver, British Columbia, Canada.

Joyal, R., J Richard. 1986. Winter defecation output and bedding frequency of wild, free-ranging moose. Journal of Wildlife Management 5(4):734-736.

McDougall, L. 1997. The complete tracker: tracks, signs, and habits of North American wildlife. The Lyons Press, New York, New York, USA.

Parker, L. R. 1990. Feasibility assessment for the reintroduction of North American elk, moose, and caribou into Wisconsin. Wisconsin Department of Natural Resources, Bureau of Research.

Renecker, L. A., R. J. Hudson. 1986. Seasonal foraging rates of free-ranging moose. Journal of Wildlife Management 50(1):143-147.

Snyder, S. A. 1991. Alces alces. http://www.fs.fed.us/database/feis/animals/mammal/alal/all.html
Accessed 23 October 2003.

United States Forest Service. 1981. Mammals of the Superior National Forest in Minnesota. Superior National Forest, Forest Service - U.S. Department of Agriculture.

Wisconsin Department of Natural Resources. 2003a. DNR news. http://ua.dnr.state.wi/org/caer/ce/news/on/2003/ON030204.htm  Accessed 15 September 2003.

Wisconsin Department of Natural Resources. 2003b. Elk in Wisconsin. http://www.dnr.state.wi.us/org/land/wildlife/Elk/index.HTM  Accessed 9 September 2003c.

Wisconsin Department of Natural Resources. 2003. Moose on the Loose! http://www.dnr.state.wi.us/org/caer/ce/eek/critter/mammal/moose.htm  Accessed 9 September 2003d.

Reference written by Erin Williams, Biology 378 student.  Edited by Christopher Yahnke.
Page last updated 4-5-04.