Moose (Alces alces) antlers grow at an amazing rate, sometimes over one-half inch per day, and their front feet can be lifted nearly shoulder high, enabling it to travel easily over fallen trees and through deep snow. Moose are excellent swimmers and can dive up to 18 feet for their preferred foods.
Habitat
Moose use different habitats from summer to winter. They are excellent swimmers and are frequently seen feeding on water plants in ponds during summer. Moose can dive up to 18 feet for these preferred foods which are sought because they have high concentrations of macroelements such as sodium, calcium and phosphorus. These macroelements are important for antler development, lactation, and body growth.
During the hot months moose can suffer from overheating and must have access to dense shade or cooling waters. For these reasons, lowland softwood forests, beaver ponds and other shallow bodies of water are favorite spring and summer habitats for moose.
Moose are generally not a social species, but several may be seen together especially at preferred feeding sites. Clearcuts are used throughout the year with the animals moving to hardwoods located near softwood cover in the fall. These forest types usually provide more winter food, especially in recently cut-over areas.
Moose will seek softwood shelter when snow depths reach approximately 35 inches, the snow gets a heavy crust, or during extreme cold and windy conditions.
Reproduction
The breeding or rutting season for moose occurs from mid-September through mid- October. Bulls are capable of breeding during their second fall when they are known as yearlings, but most breeding is done by older, more dominant bulls. Although both sexes usually remain within a ten square mile area throughout the year, young bulls may move much farther during the rut.
Bulls in the rut will thrash trees and shrubs with their antlers and dig pits in the ground into which they urinate and spread scent. Cow moose are attracted to these pits, and bulls will constantly travel to their various pits checking for the presence of cows. Bulls are also aided in their search by the loud "bellowing" call of the cow in heat.
Strenuous shoving matches between bulls may occur to establish dominance for breeding. If accepted by a cow the dominant bull will stay with her for up to a week. In forested habitats such as Vermont has, each bull will probably breed only a few cows before all cows pass through their "heat" or "estrus" period.
Some cows have their first calves at two years of age, but most will not calve until age three. Cows between the ages of three and nine are more likely to have twins than are two- year-old cows, which generally give birth to only one calf.
The pregnancy period for a moose is about 243 days and most calves are born in mid- to late May. Calves weigh 25 to 35 pounds at birth and grow very rapidly, gaining one pound per day during the first month and two to three pounds per day during the second month.
Calves are generally weaned by mid-October, at which time they weigh 300 to 400 pounds. A durable bond is formed between cows and their calves, which will last until the following spring when new calves are born.
Moose are prolific. In healthy populations most adult cows (2+ year-olds) are bred, and over half may give birth to twins. Up to 50% of yearling cows may also breed, especially on good habitat but generally only one calf will be born.
Under ideal conditions moose populations may expand by 20 to 25% annually and dramatic increases have occurred when moose occupy new habitats, especially in the absence of major predators. For example, 31 moose stocked in one area of Colorado in 1978-1979 had increased to a herd of 170 by 1988, even with losses to poaching. Increased cutting of forests in Scandinavia contributed to moose population explosions in the 1970s. The moose population in Finland grew from 15,000 in 1969 to 100,000 in 1980. At the same time, hunter harvests increased from 5,000 to 50,000 moose annually.
Moose numbers eventually will decline, however, if population growth continues unchecked, usually as a result of malnutrition caused by overbrowsing on winter range.
Poor winter range causes both increased mortality and reduced reproductive rates. A classic example of such a population crash occurred at Isle Royale in Michigan where a 1930 population of between 1,000 and 3,000 moose over browsed their range and declined to less than 200 by 1935.
Mortality
The primary known cause of non-hunting moose deaths (mortalities) in Vermont is motor vehicles. Since 1980, 67% of these reported mortalities were due to collisions with motor vehicles. Another 8% were suspected brainworm, and the remaining were due to a variety of causes such as winter ticks, accidents, and illegal shooting (poaching). It is unknown how many moose are lost annually to predation but it's likely that calves are occasionally killed by bears and coyotes.
The brainworm is a small worm that lives in deer and moose. Because the worm evolved with deer it does the deer no harm. Moose on the other hand, may have only recently been exposed to the worm because of northward expansion of deer range over the last century.
Moose are abnormal hosts of brainworm and it does them great harm. The life cycle of the brainworm includes several stages. The larval stage of the worm is expelled in deer droppings. Snails feeding on the droppings inadvertently ingest the worm larvae and become an intermediate host for the worm. The moose in turn becomes infected after unwittingly ingesting the snails while feeding on plants. The larvae migrate along the spinal cord to the moose's brain sometimes destroying the spinal cord as well as brain tissue. The moose may then display symptoms such as loss of balance, circling, lack of fear, blindness and paralysis. The disease generally causes the eventual death of the moose.
The winter tick is a unique species of tick that specializes on moose. The life cycle of winter ticks is different from other species of tick. Winter ticks find a host animal in the fall and complete all three stages of their life cycle – larva, nymph, and adult – on that same animal over the course of the winter. Due to the poor grooming practices of moose, they can end up carrying tens of thousands of winter ticks. The blood loss from that many ticks can severely debilitate adult moose and is enough to kill smaller moose, especially calves. Winter ticks only reach these problematic levels where moose are relatively abundant. In Vermont, that is primarily in the northeast corner of the state.
Diet
In Algonquin the word "moose" means "eater of twigs". Indeed, moose are mainly browsers, eating the new leaves and twig growth of trees and shrubs. They also graze on grasses, forbs, lichens and mushrooms, occasionally kneeling to do so.
Tender shoots of water lilies and other aquatic plants are preferred summer foods when available but moose are not dependent on them. After the fall frosts and winter snows either kill or deeply bury non-woody (herbaceous) foods, moose must turn to woody twigs for food.
Foods consumed by wintering moose vary, depending on preference and availability. Moose in the Northeast often browse on aspens; red, mountain, and striped maple; grey and white birch; willow; ash; pin cherry; hobblebush; and balsam fir. Moose also will strip and eat the soft bark of mountain ash and red, mountain and striped maples.
Moose and other closely related wildlife such as deer and elk like to feed at salt licks. At these areas moose lick or eat soil which has a high concentration of minerals such as sodium and calcium. Historically, naturally occurring salt licks were known to North American Indians and colonists as good hunting areas for large mammals. With the advent of civilization a new type of salt lick has developed. These man-made licks occur where road-salt runoff accumulates in the soil. The attraction of moose to these roadside salt licks often creates a hazard to both moose and motorists.
Management
The management of Vermont's moose technically began in 1896 when a law was passed affording the species complete protection. Modern moose management began in Vermont in 1992 with the adoption of a Moose Management Plan. The plan was developed by the Vermont Fish & Wildlife Department from biological data derived from studies conducted in Vermont since the early 1980s, applicable results of studies conducted in nearby states and provinces of Canada, and public opinion derived from a series of public meetings held throughout the State in 1991 and 1992. This plan was updated in 1998 and 2010.
Many Vermonters and tourists enjoy the thrill of observing or photographing moose. Others are pleased just to know moose are doing well in Vermont and may have no desire to "use" moose in any sense of the word. As far back as 1980, some sportsmen expressed a desire to legally hunt moose, and several bills to that effect were introduced into the legislature. The department opposed these proposed bills until 1991 when the data indicated the population could support a limited moose hunting season.
Moose population management through regulated hunting is an important component of the Moose Management Plan. Moose hunting in Vermont is regulated by a special license and is limited to a specific area with a specific number of licenses for the area determined annually. The license allows a party of up to two hunters and a guide to take one moose during the October moose seasons. Hunters are selected by random draw from a large pool of applicants.
Vermont's first modern moose season was held in 1993 in the Essex County area where 25 moose were taken under 30 permits. In the first decade of modern moose management in Vermont, the department chose to be deliberately conservative, slowly expanding the hunt to new areas and increasing the number of permits.
By the beginning of the 21st century, however, moose populations in the Northeast Kingdom region were causing significant damage to forest regeneration and large increases in permit numbers were prescribed for these units beginning in 2004. It was estimated that the moose density in WMU E was double what the habitat could sustain, causing over-browsing and poor forest regeneration, which was not only impacting the moose, but also other wildlife species that utilize low growing trees and shrubs for food and cover. Landowners, especially large industrial forestland owners whose livelihood and investment depends on a healthy and growing forest, were especially anxious to see moose densities reduced. After several years of very high permit allocations, the populations in D2 and E were reduced to target levels and permit numbers were reduced accordingly.
However, several other factors have combined to limit moose numbers over the past decade. In most of Vermont, a lack of young forest habitat limits the number of moose the landscape can support. A higher incidence of brainworm, associated with higher deer numbers, also limits the number of moose. In WMU E, the colder climate and abundant commercial timberland result in ideal moose habitat. However, due to their greater abundance, or population density, moose in that region are heavily impacted by winter ticks. This causes lower reproductive rates and higher mortality, particularly for calves. Vermont's 2020-2030 Big Game Management Plan sets moose population objectives for each wildlife management unit. Currently, moose hunting occurs only in WMU E, where moose remain abundant and moose numbers must be controlled to limit the abundance and impacts of winter ticks.
Biological data and public desires will continue to be used to guide future moose management. With careful management, moose will continue to be an important, fascinating and enjoyable component of Vermont's wildlife resource.
Status
Moose primarily inhabit the northern evergreen (boreal) forests and tundra regions of the world including Europe, Asia and North America. In the eastern United States they are found in New England, New York, northern Wisconsin, Michigan and Minnesota. They are also found throughout Alaska, Canada and parts of the Rocky Mountains from Idaho to Colorado.
Moose occur throughout much of Vermont but are most numerous in the Northeast Kingdom (roughly half of all moose in Vermont are found in Essex County) and along the spine of the Green Mountains from Canada to the Massachusetts state line. The Vermont moose population is relatively stable at around 2,000 animals.