Moose (Alces alces) are one of the largest land mammals in North America and are quintessential residents of northern latitudes. Given the cold northern climates that they reside in, many wonder, do moose hibernate?
Despite living in some of the coldest places in the northern hemisphere, moose do not hibernate. Living and working in Alaska, I regularly see moose active all year long. In fact, I probably see more moose in the winter as they try to avoid the deep snow found in the woods.
Moose are very well-adapted for an active life during winter despite the cold temperatures and potentially deep snow.
In this post, I’ll dive into the science behind why moose don’t hibernate and how they actually survive living in harsh winter climates.
Do Moose Hibernate?
Moose do not hibernate in winter. They evolved to be active all winter long. In fact, no species in the family that moose are part of (i.e., Cervidae; the deer family) hibernate. In North America, these include both black-tailed (Odocolieus hemionus) and white-tailed deer (Odocoileus virginianus), elk (Cervus elaphus), and caribou (Rangifer tarandus).
Why Don’t Moose Hibernate?
Hibernation in a physiological process by which an animal significantly reduces their metabolism (i.e., reduced heart rate, reduced respirations, reduced body temperature) to help conserve energy during winter when food is scarce or weather conditions too extreme. So, if moose could simply hibernate and reduce their energy needs until spring, why wouldn’t they?
Well, unlike other species that hibernate (e.g., arctic ground squirrels; Urocitellus parryii), moose still have access to a lot of different foods during winter. Additionally, moose are able to survive in extremely cold temperatures without needing to spend a lot of extra energy given their physiological adaptations.
So because food is not limited for them and it doesn’t cost them a lot of extra energy to deal with cold, moose don’t have a need to hibernate.
How Do Moose Survive the Winter?
Moose live in northern climates where the snow can be quite deep and the temperatures quite cold. In the most northern portions of their range, moose can experience winter temperatures that drop below -40° F (-40°C). They must therefore have a variety of adaptations to survive in such harsh winter conditions.
Cold Tolerance
Moose are extremely adapted to living in cold environments. One study found that moose can tolerate temperatures as low as -22°F (-30° C) without needing to increase their metabolism to keep warm. That means, they don’t need to expend extra energy to stay warm at these temperatures. In reality, warm temperatures are more a challenge for moose than the cold!
What Do Moose Eat in Winter?
Moose store large quantities of fat during summer and autumn which allows them to compensate for reduced access to their forage species during winter.
Moose reduce their rate of feeding in winter but still must eat to ensure they have sufficient energy to last through winter. While winter diets will vary across the range that moose occur, they generally consist of deciduous trees and shrubs (i.e., those that loose their leaves in winter) such as birch (Betula sp.) and willow (Salix sp.). Moose prefer to the new growth of plants as they are easier to digest and typically more nutritious.
But, as the snow gets deeper throughout winter, their access to forage declines and they can only eat vegetation that is above the snow line. While this generally limits the availability of their food, they may access to some forage that was inaccessible to them when the snow is absent.
Moving Through Snow
Snow is a significant factor affecting moose movement during winter. When snow depth is around 1.5 feet deep, moose have been shown to reduce their daily movements to as little as a 1/3 a mile (500 m) compared to 1-2 miles when snow is absent.
The time I am most worried about running into moose, aside from a cow with a newborn calf (scary!), is when I’m on a trail in winter and the snow is deep off the trail. Moose love using packed down snow trails in winter because it significantly reduces their energy expenses. As a result, moose generally avoid areas with deep snow within their home ranges.
Predator Avoidance
Moose can be quite vulnerable to predation during the winter time because they are generally in lower body condition during winter when food is less available. They can also be more at risk of predators when moving through deep snow where species like wolves (Canis lupus) can more easily move and attack moose.
As a result, moose choose areas in the landscape with lower densities of wolves and shallower snow. But moose can still be taken by wolves in winter, especially adult females and young moose.
Summary
So, do moose hibernate? Nope! Moose are quite adapted to cold winter climates and actually have a harder time regulating their temperatures when it’s warmer out. They eek out a living in winter by eating shrubs and other woody vegetation.
We see moose regularly during the winter here in Alaska. When the snow is more than a foot deep, we often run into them on the trails because it’s easier for them to walk on. Every Alaskan is on high alert for moose in winter (and the rest of the year!).
Curious to learn more interesting facts about wildlife? Check out my other wildlife information posts. Or check out my post on whether moose can swim or not.
