What does it take to move elk to new pastures?

By Bruce Auchly

FWP Region 4 Information Officer

On the last day of the 2014 general hunting season on the Rocky Mountain Front, a large number of the Sun River elk herd were still in the back country not out on the windswept hills of the Sun River Wildlife Management Area.

Perhaps 85 percent were on U.S Forest Service lands, including the Bob Marshall Wilderness. This despite two subzero periods in November and a foot or more of fluffy snow in places.

A large number of elk in the unreachable back country as the season ends translates into fewer elk taken by hunters. For the curious, perhaps, it helps to understand what it takes to move elk from their fall gathering spots to wintering areas.

Until winter weather pushes them, elk quickly respond to hunting pressure by seeking secure, or safe, areas. Sometimes that can be privately owned lands that do not allow hunting. Other times it can be public lands that are inaccessible.

Then, elk will move from a mountain redoubt only when there is the right combination of snow and cold.

Now snow will move hunters, and cold will move hunters; believe me, I know from personal experience.

But elk are different. They are big animals with lots of body mass that produces lots of heat. That and their thick fur coat can take a lot of winter.

An elk's winter coat has two layers: a dense, woolly undercoat topped with thick, long guard hairs.

Each guard hair contains thousands of tiny air pockets making it waterproof and providing insulation. In very cold weather, snow on the thick guard hair coat often doesn't even melt because the animal's body heat is held in by the undercoat. Also, elk can make their hair stand on end, creating a thicker coat that traps more air.

Typically, it takes deep or crusted snow, or some combination, and a prolonged period of temperatures below freezing to force elk to migrate. Of course a snowstorm that produces incredibly deep snow will move them, but crusted snow or ice makes it more difficult for elk to reach food.

In Montana, elk are primarily grazers; that is their food is grass, though they are adaptable and if necessary can browse like deer and nip the ends and buds of trees and shrubs.

Where 8 to 12 inches of snow may force deer to move, elk are much bigger and not threatened by a little snow. The average chest height of a bull is 35 inches; for cow elk the average is 33 inches.

That means a foot or two of fluffy snow is not an impediment to an elk to move or dig. However, snow that has melted and refroze, presenting a sheet of ice, can be a barrier to an animal searching for grass.

Throw in several days or a week of subzero temperatures and elk will move to find food. East of the Continental Divide, they often seek out grassy windswept or south facing hills that offer exposed grass and the security of openness to watch for predators.

Some years, when winter hits hard and early, elk will leave their secure habitat even when faced with hunting pressure.

Other years, like this past hunting season, elk will stay put where they can elude hunters and have plenty of food.