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Ungulate Research

Wild and domestic ungulates occur on nearly all national forests and grasslands across the nation. Managing for these species is a challenging balance between protecting ungulate populations and their habitats and conserving and managing other natural resources. Elk, deer, and cattle are often drivers of ecosystem patterns and processes and have million-dollar impacts on recreation, agriculture, and natural resource management. Elk and deer also generate millions of dollars annually to state wildlife agencies from sales of hunting licenses, and elk and deer viewing generates much additional revenue to local and regional economies. By contrast, the potential for elk and deer to compete with livestock, to damage agricultural crops and tree plantations, and to modify plant succession makes ungulates sources of conflict between private and public land managers.

Image Credit: Rachel Cook

Resource managers and policymakers need science-based information on how elk and deer respond to management activities and other land uses, such as fuels management, timber harvest, traffic, and livestock grazing. They also need information on how elk, deer, and livestock herbivory may influence the development of plant communities, particularly after wildfire, prescribed fire, and exotic plant invasions. Forest Service Research & Development provides information to land managers across a variety of landscapes to make informed management decisions about issues such as forage improvements, access management, and mitigation of forest browsing.


Forest Service R&D explores the dynamics of ungulate populations and their habitats to inform management practices to sustain biological diversity, economic and ecological productivity, and forest health. In the Northeastern US, white-tailed deer have been a particularly dominant force in shaping forest vegetation communities for many decades, and the problem is growing in other regions. In the 1900s, most deer were extirpated from this area by extensive market hunting, but deer populations have since rebounded to densities that exceed historic levels. High deer densities have led to shifts in patterns of plant composition and abundance throughout much of the temperate forests of the US. R&D scientists have been investigating effects of deer on forest communities since the 1940s and recently have found that the same number of deer might be too many in some conditions but just right in others. Forest Service research provides important guidance to land managers, both agency and private, with emerging deer problems. With recent changes in game management policies leading to lower deer densities locally, R&D can also provide valuable and practical information about indicators and rates of forest recovery, as well as forest restoration practices.

In the Western US, land managers are concerned with the potential effects of timber management, livestock grazing, road use, recreation, and hunting regulations on mule deer and elk as well as the constraints often associated with these activities related to sound management of deer and elk. In the 1980s the Starkey Project, a partnership between the Forest Service Starkey Experimental Forest and Range and the Oregon Department of Fish and Wildlife, began to address these key research challenges. The Starkey Project provides R&D a unique opportunity, with the largest research enclosure ever built to study ungulates (40 square miles enclosed by 27 miles of fencing), to conduct long-term studies to evaluate deer, elk, and cattle response to intensely managed National Forests within a controlled research setting.

Evaluating Effects of Ungulates on Vegetation

Forest Service scientists conduct long-term research across a variety of plant communities at multiple scales to understand how ungulates, both wild and domestic, impact ecological processes and vegetation structure and composition.

Highlighted Research

Deer and Plant Community Interactions

Image Credit: Northern Research Station. Researching the impact of deer browsing on vegetation.

A four-year Forest Service R&D study is investigating deer and plant community interactions at multiple scales. The study has two objectives: (1) evaluate the relationship between deer densities and browse-impact on vegetation, and (2) determine the degree to which forest landscape heterogeneity influences foraging behavior of deer and, in turn, the impact on browse. The research will test these relationships by building on the ongoing research conducted by R&D scientists, in which a decade of both forest and deer management has created a 30,000-hectare area where deer populations, habitat heterogeneity, and browse impact all vary by as much as two orders of magnitude. This variation provides an exceptional opportunity to evaluate impacts across a broad range of conditions. Scientists will use retrospective analyses that couple existing long-term vegetation and deer population data with spatial metrics known to influence deer behavior, such as edge density or abundance of early successional habitat. Researchers will also implement an experiment to test browsing effects on vegetation across a wide gradient of landscapes. This information will lead to the development of innovative management practices, with guidelines for a new paradigm whereby foresters work proactively to manipulate forest landscapes at appropriate scales to mitigate the impacts of deer browsing, instead of reacting to high deer populations by recommending culling programs or expensive fencing solutions.

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Understanding Ungulate Movements and Distributions in Space and Time

Scientists develop models and other tools to predict where elk, deer, and cattle occur given current conditions or those resulting from planned management activities or from climate change.

Highlighted Research

New Models Aid Management of Elk Populations and Habitat

Elk are widely distributed across the Pacific Northwest, where they are an integral component of the landscape. Elk management and land-use plans, however, often incorporate models that do not reliably estimate suitable elk habitat. To meet this need, FS researchers updated elk nutrition and habitat selection models with an innovative approach that incorporates the latest research on elk nutrition and current spatial data. They used elk radio-telemetry data from many sources and geographic areas to develop and validate the models. R&D scientists also created maps of nutritional adequacy for elk to evaluate how land management activities, like road closures and thinning, limit the degree to which nutritional resources are available to elk. Modeling results are being used to coordinate management of elk habitat and populations among state and federal agencies, Indian tribes, hunting organizations, and other interested groups. R&D hosted a workshop for model users in which several beta testers, including biologists with the Muckleshoot Indian Tribe, Bureau of Land Management, and FS National Forest System, demonstrated how they are incorporating modeling results in local habitat evaluation and land management planning.

The elk modeling project is being conducted in two phases. The first phase entailed the development of Westside models that apply to elk on summer ranges in western Oregon and Washington. The second phase of modeling, nearing completion, addresses summer habitat conditions in the Blue Mountains of eastern Oregon and Washington. A final workshop will be held in late April 2013 to explain the Blue Mountains models and demonstrate their utility in local management with hands-on sessions for model application.

Partners cooperating with the FS Pacific Northwest Research Station for this research include: Boone and Crockett Club, Lower Elwha Klallam Tribe, Makah Nation, Muckleshoot Indian Tribe, National Council for Air and Stream Improvement, National Fish and Wildlife Foundation, Oregon Department of Fish and Wildlife, Oregon State University, Quileute Tribe, Rocky Mountain Elk Foundation, Sauk-Suiattle Indian Tribe, Sporting Conservation Council, USDA Forest Service Pacific Northwest Region, USDI Bureau of Land Management, Washington Department of Fish and Wildlife, and West, Inc.

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Predicting Responses of Ungulates to Human Activities

Research investigates the effects of human activities on ungulate habitats and animal performance at landscape scales commensurate with restoration and land use planning. Activities range from traditional management activities (e.g., timber harvest, road construction) and energy development to recreational uses such as hiking, off-road vehicle use, and hunting.

Highlighted Research

Examining the Response of Elk and Deer to Off-road Vehicle Activities

Recreational use is increasing rapidly on public lands, but few studies have evaluated its effects on wildlife. To address this need, R&D scientists with the Starkey Project conducted a three-year study to evaluate responses of mule deer and elk to ATV riding, mountain biking, horseback riding, and hiking. Elk movement rates were substantially higher during all four activities, particularly during ATV and mountain bike riding compared to hiking or horseback riding. Mule deer were much less responsive to off-road activities. Results have national implications for recreation management and have been used in travel management planning for National Forests in the western United States.

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Research Contacts

Scientist Contacts
Thomas Hanley Research Wildlife Biologist, Boreal Ecology Team Leader, Pacific Northwest Research Station
W. Keith Moser Research Forester, Northern Research Station
Todd Ristau Research Ecologist, Northern Research Station
Mary Rowland Research Wildlife Biologist, Pacific Northwest Research Station
Alejandro Royo Research Ecologist, Northern Research Station
Mark Rumble Research Wildlife Biologist, Rocky Mountain Research Station
Mike Wisdom Research Wildlife Biologist, Pacific Northwest Research Station
Scott Stoleson Research Wildlife Biologist, Northern Research Station
Susan Stout Project Lead and Research Forester, Northern Research Station
Mike Schwartz Research Ecologist, Rocky Mountain Research Station
John Kilgo Research Wildlife Biologist, Southern Research Station
Additional Contacts
Monica Tomosy Wildlife Research National Program Lead

Additional Resources and Publications