Why do elk seek shelter? The case against the need for thermal cover.

Abstract

Many elk populations in the Northwest are declining (20 to 40 percent or more). Why? Nobody really knows. But the situation calls for a more explicit understanding of the influence of habitat management on elk herd demography and productivity. John Cook and Larry Irwin, scientists with the National Council of the Paper Industry for Air and Stream Improvement; Larry Bryant and Jack Ward Thomas, scientists formerly with the PNW Research Station; and Bob Riggs, wildlife biologist with Boise Cascade Corporation, conducted a 4-year study in the Blue Mountains of northeast Oregon to clarify elk habitat requirements specifically--the need of elk for thermal cover.

No positive effect of thermal cover was found on body condition of elk during any of four winter-long and two summer-long experiments. Although such studies cannot prove that thermal cover is never important, researchers concluded that management decisions regarding thermal cover should be considered in relation to other habitat variables, in particular, the relative contribution of each variable to herd productivity and management emphasis on providing thermal cover should be relatively low in most climatological settings.

Citation

Duncan, Sally. 2000. Why do elk seek shelter? The case against the need for thermal cover. Science Findings. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. February (22): 1-5.