Fun Facts to Know
Moose evolved on European continent more than a half-million years ago. Over hundreds of thousands of years, they migrated eastward across northern Europe and Siberia. During an extended cold period in the history when vast amounts of the Earths water was deposited in glacial ice sheets, the level of the Bering Sea dropped significantly. A passing over snow and ice across what we now call the Bering Strait was possible and moose (and other species) migrated from Siberia to Alaska. Migration across the North American continent continued. Today, moose inhabit an extensive area of land in the Northern Hemisphere around the globe.
Habitat and Diet
Moose prefer cool climates and inhabit various types of forests in the Northern Hemisphere. During warmer summer months, areas near water are desirable.
Moose eat a variety of different plants. Available vegetation depending on season dictates their diet. Leaves and small branches of trees and shrubs are common food choices (called "browse") for much of the year. Because they have no upper front teeth, one browsing method is to grip a branch and pull sideways to strip off all the leaves with their tough lips and tongue.
Areas previously burned by forest fires with new growth of small trees and shrubs provide good browsing areas for moose. It is possible the increased control of forest fires by humans has inhibited availability of these areas.
In summer months, water plants such as pondweed and certain types of pond lilies attract moose to lakes and streams. It is now believed the high sodium content of water plants is significant for their diet. It is common to see moose standing in water with only their heads exposed. They may disappear completely when lowering their head to pull up the soft plants. Moose have even been known to dive as deep as 18 feet to grasp the plants they desire!
Cold winter seasons force moose to rely on browse with lower nutritional value. By instinct, they concentrate on eating late in the fall following the mating season. It is necessary to add nutritional resources to their body prior to the harsh winters when moose may loose up to 30% of their body weight.
Only male moose grow antlers and the broad web with extending points give the moose a unique and recognizable appearance. Antlers begin to grow early in the spring from areas attached to the upper skull in front of and above their ears. As they grow they are covered with a soft skin called "velvet" which has fuzzy appearance. The velvet covering of the antlers encases blood vessels which feed the growing antlers. While antlers are growing, they are relatively soft and susceptible to injuries. An injury during the growing phase often causes some degree of deformity to the final shape. If the injury is not great, the deformity may not be apparent the following year.
Following the end of warm summer months, the antlers reach the maximum growth and begin to harden. The velvet skin is no longer needed and begins to die. Bulls vigorously rub their antlers against shrubs and trees to dislodge and remove the velvet and display the long-covered bony structures.
Like many types of antlered animals, moose antlers generally increase in size each year. Exceptions include antlers on unhealthy animals due to sickness or lack of adequate nutrition. Antler size of prime bulls is impressive. They may weigh 50 to 60 pounds or more and the largest recorded set measured nearly 7 feet across. Antlers are important visual symbols indicating social position and condition of the bull to other bulls and cows. Late in autumn or early winter, following the mating season, antlers are shed and the bull is freed from a heavy burden to carry during the harsh natural winters. Shed antlers are not common to find because they contain desirable nutrients and are eaten by small woodland animals such as squirrels, mice, and porcupines.
Seasons of the Moose
During the spring season, when the increasing length of daylight has once again warmed the woods, expecting cow moose give birth to one or two calves following a gestation period of about eight months. Twin calves are less frequent if moose population density is higher, if the food supply (or its nutritional value) is lower, or if the cow is not in the best health. For young moose as with most wild animals the first months of life are the most dangerous. Wolves and bears are natural predators and a threat to calves. The cow will vigorously defend her offspring using hard, sharp hooves and a powerful kick as weapons. Even though calves can run within a few days of birth, avoiding detection often is a better defense. Calves are a much lighter color than their dark-haired parents and more difficult to see in brush and tall grasses.
Warmer temperatures also initiate the growth of a lighter fur coat for the moose. They may rub against shrubs and trees to scratch themselves and remove clumps of heavy fur. The resulting scraggly appearance is not a problem unless the weather turns unusually cold again. Moose which have rubbed off too much fur may no longer be insulated well enough and die from hypothermia.
New growth and buds on vegetation provide much better nutritional browse for the moose as they wander from their winter feeding territory. As the spring progresses and frozen lakes and ponds thaw and warm, many moose move near wetland areas.
Hot summer days are likely not relaxing for moose. They may spend extended periods of time in the water browsing on plants or simply attempting to stay comfortably cool. Another potential reason for entering the water is to avoid thousands of swarming flies constantly pestering the animals. Biting flies appear to be mostly a nuisance and not a serious threat to moose.
Autumn is the most active season for moose. This time of year begins the mating period, called the "rut". Bull moose thrash shrubs and trees to shed the velvet from their antlers. Bull moose challenge each other for territory and mating rights. Visual supremacy of antlers avoids many direct challenges without physical contact. When bulls do engage in physical duels, only rarely is one of them seriously injured.
The mating season is usually the only time when moose may be seen together as a "family" including bulls, cows and calves. In reality, this is not a family unit at all. In fact, the calves may well be offspring from a different bull. The bulls only intention during this time is mating with one or more cows.
Prime bulls generally are the first to gather cows and mate. Lesser bulls may not acquire suitable cows until later in the season. Following the rut, and commencing with colder weather, antlers are no longer a vital necessity and are shed roughly relating to order in which mating occurred. Carrying the burden of antlers longer into the colder season may be a detriment to lesser bulls. Browsing intensifies during this time as moose instinctively prepare for the harsh winter to come.
Cold winter months are the most difficult for moose mainly due to a significant decrease in available browse. Deep snow inhibits their ability to move to areas where additional browse is obtainable. Occasionally, groups of moose will gather, or "yard" together in an area where browse is more abundant. Unusually heavy snow, especially if it accumulates early in the season, can have a dramatic impact on moose fatality. This occurred in northern Minnesota and mid-Canada during the 1996-1997 season. (It also affected other species, such as deer, in a similar manner.)
Both the type of browse and its nutritional value are limited by the winter months. Obviously, water plants are unavailable to due frozen lakes and ponds. Missing also is tender, new growth on trees and shrubs causing moose to feed inward on the barren branches. Moose may even tear strips of bark off certain types of trees for browse. (Could one say their bite is worse than the bark?) Long, cold months consume moose body reserves hopefully well-stocked from fall browsing. Up to thirty percent of its weight may be depleted before renewed food sources appear in spring.
Spring season starts the new life cycle once more. It is time for a rude awakening for the yearling calves. Following a year a nurturing, guidance and protection, cows now use body language and aggressive behavior to inform the yearling it is no longer welcome company. The demands of caring for an expectant new-born likely cause cows to act instinctively in this manner. A perplexed calf is left to fend for itself for the first time in its life. Fortunately, having survived its most precarious year, a much longer existence is a high probability.
Threats to the Moose
Due to their size, healthy, adult moose have few natural predators. Large brown bears, or grizzlies, are a potential threat. However, the habitation range of bears that size is much smaller than that of moose. Black bears and wolves are serious threats to calves and in some areas cause fatal results for a relatively high proportion of offspring, in spite of valiant defensive actions by cows. The most serious life-threatening disease is called brainworm, a parasite carried by white-tailed deer. While the parasite apparently does not affect deer, it is excreted in their droppings. Organisms feeding on droppings find their way to browse and are unknowingly consumed by moose. The parasite inflicts usually fatal damage to the moose nervous system.
Moose face an unnatural threat only from human actions. Hunting, loss of habitat, chemicals and accidental fires may impact moose populations. However, moose also have many human allies working hard to guarantee future generations will be able to see and appreciate this magnificent animal.