Wintering - Freight Train through a Snow Bank (Moose)
We've all heard the moose called “swamp donkeys” because their preferred habitat is in the swamps and near the lakes and bogs. In the winter however, when these swamps and bogs freeze over, where do they go? The large and majestic moose are known to inhabit our forests, and we often see signs of them, but rarely catch a glimpse of them. Through the winter months it seems even less likely to see them, as these enormous animals never seem to be sighted, to such a degree that it almost seems like they must have “flown south” or “hibernated” as some of our other species do.
These animals can grow to be as large as 1400 pounds, yet they can move almost perfectly silently through our forests when they want to, undetected. They have massive antler spreads that can be over 6', and yet they are able to slip through with barely a sound. Moose are the largest member of the deer family, and their allure is such that hunter spend thousands or even tens of thousands of dollars to come to our region on guided hunts for a chance to harvest one of these enormous animals.
In the woods of New Brunswick and the other eastern provinces and states, we have a subspecies known as the “Eastern Moose.” Though some believe them to be stupid because of their tendency to not run when they encounter danger, biologists tell us this actually gives them a better chance to fight off predators. A fleeing animal only incites canids such as wolves and coyotes to give chase, whereas the moose has a better chance by standing his ground and readying for a battle. They can become aggressive when startled and one certainly would not want to tangle with a 1400 pound animal that can move surprisingly fast. The top speed of a moose is in the area of 55 kilometers per hour (35 mph), aided by their long legs.
Although they certainly do not migrate south, moose will often move into a forested “winter” range when the cold and snow begin to come. They do this before snow depths are limiting. When they encounter particularly high snow depths, they may move even deeper into a forested area to enable them to still get around. A winter range is much smaller in size to their summer and fall ranges as they don't move as much to conserve energy. Compared to open areas, the move to a heavily forested range will give them the advantages of less snow depth, less wind, and more moderate temperatures. Perhaps it is due to this move into the deep, heavily forested areas that we never seem to spot them in the winter. Interestingly, in Western Canada where they have far more mountainous terrain, sightings are greater in the winter months as the moose tend to stick down in the valleys where more of the highways and roads are, to stay sheltered. In the east however, they don't really have mountains to deal with.
Moose are able to handle the cold very well and may even find it more comfortable during the winter than in the heat of the summer. They suffer in the heat of the summer and have been known to spend several hours per day cooling off in water if it is available. It is said that calves begin to feel the cold at a temperature of -30 degrees Celsius (-22 F) however adults can handle temperatures far colder. Moose in fact are insulated so well by their hair that a temperature of -5 degrees Celsius (23 F) can make them pant! They rely on the cover of softwood to keep them cool, and will sometimes lie down flat on the snow to try to cool off.
Snow can form a bit of an obstacle, however because of their long legs they are able to handle snow depths of 3 feet quite well. A demonstration of a moose running through the snow in the winter can be found here. However, they will restrict their movement if the snow has a crust to it. Moose will sometimes “herd up” in the winter order to make their movement easier and enable them to move through the snow easier to locate food. Moose require a high water intake, and will eat snow in the winter if they need to in order to meet those needs. They will bed down in the snow, and if you find an indentation or clearing around four feet wide in the snow, it is likely you have found a moose bed.
Their diets in the winter change and they tend not to require as much food as in the rest of the year. During the spring, summer, and fall, they will eat about 50-60 pounds of food daily in order to maintain their size. In the winter they will eat somewhere in the range of 25-30 pounds of largely twigs and shrubs per day. Winter is a time of hunger for them, and they restrict their activity and food intake to preserve energy. If food is scarce they will strip the bark from trees, especially poplar. At the right you can see a picture of some small hardwood trees in the winter that were likely peeled by a feeding moose.
Male moose, known as “bulls” carry around an impressive set of antlers that can weigh as much as 75 pounds and be as wide as 2 meters. They shed these antlers around mid-December to January which will save energy and help their mobility. Some younger bulls have been known however to carry these antlers through to April. They begin to grow them again in the early spring.
A major threat to the moose population in our province in recent years have been the winter ticks, and some areas have seen their population take a serious hit from deaths due to these ticks. These moose are known as “ghost” moose because the white base of hair shaft is all that remains. Scientists are trying to study why these deaths are occurring more frequently in recent years as the two species have coexisted perfectly fine for thousands of years. They are a native parasite, and parasites should not be fatal to their hosts. However winter die-offs from ticks are increasing across North America. The winter tick grows to an impressive size of up to 15mm, peaking toward the end of winter. When infestations are significant, thousands of ticks can attack a single moose. Studies by the University of Alberta indicate that if a calf is infested by 30,000 ticks they must replace nearly 60% of their blood volume in March and April. An infestation of 70,000 ticks forces the moose to replace 112% of their blood volume in the same time frame. Moose infested by this volume of ticks will lose between 40 and 100% of their insulating hair leaving them at risk of hypothermia. They also become preoccupied with grooming to try to deal with the itching, which can put them at greater risk of predation. Time that is better spent resting or feeding is instead focused on licking, rubbing, and scratching. If the moose is heavily infested with ticks, they can exhibit abnormal behaviour, suffer weight loss and hair loss, loss of blood, poor physical conditions. The cumulative effects of all these symptoms can make them more vulnerable to predators and severely affected animals may die. In the winter of 2013-14 it was thought that perhaps as much as half the moose population in zone 20 of New Brunswick may have died, and experts say the majority were from winter tick infestations.
The state of Maine has been investigating whether it might be the combination of heavy winter tick infestations along with possible “lungworm” infections that are causing the heavy winter-tick mortality. A lungworm is a nemotode causing bronchitis and lung lesions. The combination of these two problems could be simply too much for their system to take, and are making them vulnerable to die from the parasite and disease.
Although we don't yet have a definitive answer on why the winter ticks have begun having this effect on moose across the continent, biologists are putting a great deal of effort into figuring it out. Since the 1900s, the moose population has dropped in almost every area of North America, some very dramatically. Moose hunting is an enormous industry and states and provinces alike are interested in protecting their revenue. Hunters and outdoor obsessed individuals should be hoping for their success, as a world without these majestic creatures would be a sad one indeed.
So if you're out in the deep woods in the winter months, far from the bogs and lakes where you would normally see a moose, where the limbs are thick and the canopy heavily forested... you may just happen upon a wintering swamp donkey!
Contact us and let us know!