Cows give birth to calves in late May when it is still cold and spring has not yet really arrived in the boreal forest. At this time cow moose are malnourished and not yet recovered from the past winter’s ticks. It seems too early, but an early start is essential so that calves are prepared to survive winter.
At birth calves weigh only 30 pounds, but can walk within hours of birth. For the first two months of life, much of the calf’s nourishment comes from the mother’s milk. Calves begin testing different foods within a couple of weeks, and by late July calves eat large amounts of vegetation. By late fall, calves are fully weaned. At this time, healthy calves weigh 300 pounds, almost ten times their birth weight.
For an entire year, calves depend on the protection of their mothers. A healthy mother is a formidable defense.
Typically, eight of every ten cows are pregnant each fall. By the following spring, twenty months later, only one or two of every ten cows still have a surviving calf. By some standards the survival of a calf is miraculous; by any standard it is against the odds.
Just before their first birthday, when cows are ready to give birth again, calves are rejected by their mothers. After being with their mother for every moment of their lives, they begin a largely solitary existence.
While many cows are in the last months of pregnancy and raising a young calf, bull moose begin re-growing antlers each spring. During peak growth, antlers may grow three-quarters of an inch in a single day. During summer bulls spend about 25% of their energy growing antlers. This is energy that otherwise would have increased body reserves necessary for surviving winter.
By Fall, antlers stop growing and bulls prepare to mate. So focused are bulls at this time that they stop eating for a couple of weeks, and may lose 100 or more pounds. They use their antlers to compete with other males and attract females. Mating success is not guaranteed. Only healthy, experienced bulls mate. Success is determined by antler size and symmetry.
In early winter, bulls shed their antlers. They face winter handicapped by the legacy of their antlers. If they survive, they will begin growing new antlers in spring. Each year bulls grow larger antlers. They die shortly after old age makes it impossible for larger antlers.
Antlers are extravagant and disposable sex symbols, like a young man in a hot sports car. Why spend so much on antlers? It seems so wasteful.
Surviving the winter means nothing if doing so comes at the cost of not mating. Antlers are a sign of male fitness and health, and are usefully thought of as a handicap. Only the fittest moose are able to devote substantial energy to antler growth. A moose in poor health is unable to grow large antlers, and in this way antlers are an honest sign of a moose’s fitness.
Whereas cows may only give birth every other year, bulls nurture their antlers every year. This intensity takes its toll. Compared to cow moose, bulls have higher rates of osteoporosis and arthritis and shorter life spans.
During summer, moose consume thirty to forty pounds of vegetation a day. That would be like you or me eating 7 pounds of salad every day. Because each bite may contain only a few grams of food, moose bite and chew several thousand times every day. Moose patiently feed for about eight hours every day.
Moose forage is voluminous, but not very rich in nutrition. To accommodate this kind of food moose possess one of the most complicated digestive systems ever created by Mother Nature (aka, natural selection). To get the most out of their food, moose digest it a bit, regurgitate it, chew on the cud, and re-swallow it for a second round of digestion. Moose patiently chew their cud about eight hours every day.
In preparation for winter, moose increase their body weight by as much as twenty-five percent. Imagine gaining twenty-five percent of your body weight by eating only vegetable salads – no salad dressing, just the salad.
More than any other member of the deer family, moose spend time in the water. The moose’s association with water is so distinctive that moose may appropriately be considered the hippopotamus of the north country.
Moose are well-suited for spending time in water. Long, strong legs allow moose to walk easily in shallow waters and swim in deeper waters. Moose also have large, complex noses. Of all members of the deer family, moose have the biggest noses. The narial architecture of a moose includes massive cartilage, specialized muscles, folded and recessed skin, and fatty pads (see lower image). All these features may represent a complex, nostril-closing system, that allow moose to forage underwater without breathing in any water.
Aquatic environments offer much to moose. Water brings coolness. In the water, moose reduce their respiration rate by almost 30%, and their overall energy expenditure by about 10%. Water also brings nutrition. Of all the food that moose consume, aquatic plants are the richest in protein and sodium. Water also brings safety. Even a weak, vulnerable moose is considerably safer from an attacking wolf when standing in just a few feet of water.
For moose, winter is full of suffering and triumph over that suffering. It is not the cold. Moose are hardly bothered by cold. It is the difficulty of getting food. During winter, moose mostly eat twigs from deciduous trees and shrubs and the twigs and needles of balsam fir and cedar. Each bite of food is a mere gram – just 1/28th of an ounce. Moreover, twigs and needles contain only one third the nutrition of leaves that moose eat during summer.
The fare is not only meager, but also difficult to gather. The snow is deep and moving from tree to tree is difficult and energy consuming. Imagine yourself walking through chest or knee deep snow from tree to tree collecting about nine thousand twigs – one twig at a time – every day. This is how moose – an 800 or 1000 pound creature – survive the winter.
When snow is deep and foods sparse, moose restrict their intake of food because the costs of eating exceed the gains. Moose pass much of the winter resting and ruminating, in solitude and hunger. Ultimately, moose lose weight every single day, for about five months of every year. Nevertheless, most moose live to see the spring that follows each winter.
One might rightfully think that moose are awe-inspiring for their adaptations to winter. Just as rightfully, one might also think that winter is full of suffering and triumph over suffering. It is quite a powerful thing to give one’s attention to another’s suffering and triumph.