NCASI study addresses nutritional ecology of elk in the Pacific Northwest

Elk (Cervus elaphus) in the western United States are valued economically and socially, and have featured species status for federal land management planning. As a result, consideration for elk habitat conditions can have significant influence on management of federal lands.

Considerable effort has been devoted to modeling relationships between land management practices and habitat conditions for elk. However, these models vary greatly in the extent to which they consider the nutritional aspects of habitat conditions.

For many years, NCASI has been conducting research intended to develop greater understanding of how habitat conditions influence foraging dynamics and nutrition of elk in summer and autumn, and to develop information that allows the nutritional needs of elk to be integrated within landscape-scale plans, population models, and habitat evaluation models.

Recently, three NCASI scientists [John G. Cook, Rachel C. Cook, and Larry L. Irwin (retired)] and Ronald W. Davis of the University of Illinois at Urbana-Champaign reported results from a long-term study of foraging responses of elk to clearcut logging and commercial thinning, forest succession, and season across a range of stand ages and ecological conditions.

The study, which was conducted on private and public timberland in the Pacific Northwest, also assessed the extent to which plant communities satisfied nutritional requirements of lactating female elk and their calves.  The publication appears in the November 2016 issue of Wildlife Monographs. The authors’ conclusions, which are summarized in the monograph’s abstract, follow.

“Our data demonstrated that nutritional resources in forests of western Oregon and Washington are generally deficient for lactating elk in summer and early autumn. They provided evidence that inadequate nutritional resources are largely responsible for low body fat in autumn and reduced pregnancy rates reported for many elk herds in the Pacific Northwest. Our data also illustrated that nutritional value of habitats is highly variable depending on ecological context, disturbance, and succession. Thus, how, if, and where forested elk habitats are managed can greatly influence the nutritional suitability of an area. Finally, our data indicate a considerable need for integrating nutritional assessments in landscape planning processes where maintaining abundant and productive elk populations is one of several forest management goals in the Pacific Northwest.”



Cook, J.G., R.C. Cook, R.W. Davis, and L.L. Irwin. 2016. Nutritional ecology of elk during summer and autumn in the Pacific Northwest. Wildlife Monographs 195(1):1–81. http://dx.doi/org/10.1002/wmon.1020