USDA Forest Service

Pacific Northwest Research Station

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Pacific Northwest Research Station
1220 SW 3rd Ave.
Portland, OR 97204

(503) 808-2100

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2011 Wildlife

Key Findings and Products

West-side nutrition and resource selection models for elk are developed, validated, and used in local habitat evaluation and land management planning in western Oregon and Washington.

Climate change is predicted to shift wolverine distributions, habitat connectivity and dispersal corridors

Scientists map habitat connectivity, landscape integrity, and climate gradient patterns for 16 wildlife species in Washington.



New models aid management of elk habitat


Use: Tribe, state, and federal land managers use model to manage elk habitat.

Elk are widely distributed across western Oregon and Washington, and elk hunting and viewing contribute substantially to rural economies. Elk habitat models and management guidelines had become outdated, so station scientists updated elk nutrition and habitat selection models with an innovative approach that incorporates the latest research on elk nutrition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 radiotelemetry data from many sources and geographic areas to develop and validate these models. They also created maps of nutritional adequacy for elk to evaluate how public access and other factors 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. The station hosted a workshop for users where several beta testers, including biologists with the Muckleshoot Indian Tribe, Oregon Bureau of Land Management, and Forest Service Pacific Northwest Region, demonstrated how they are incorporating modeling results in local habitat evaluation and land management planning.

Contact: Mary Rowland,, Ecological Process and Function Program

Partners: 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 State University, Oregon Department of Fish and Wildlife, 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, West, Inc.


Columbian white-tailed deer avoid livestock areas as fawning habitat


White-tailed deer (Photo by U.S. Fish and Wildlife Service).Columbian white-tailed deer historically ranged throughout much of western Oregon and southwestern Washington. The deer prefer oak woodlands and savannas, ecosystems that have greatly declined since Euro-American settlement. Today, two remnant populations of the deer remain: one lives along the lower Columbia River and the second lives in the interior valleys of the Umpqua Basin in Douglas County, Oregon.

The lower Columbia River population has been federally listed as an endangered species since 1967. The Douglas County population has been protected by the state of Oregon since 1978 and is considered a discrete population with separate recovery goals. The minimum recovery goals have been met, but the deer occupies less than 5 percent of its historical range. Understanding how land use affects its fawning habitat is fundamental to supporting further recovery of the species.

Scientists found that the does avoided areas with livestock during fawning and chose to give birth in areas concealed by dense vegetation, typically along a permanent stream. Areas with livestock offered less vegetative cover.

Contact: Martin Raphael,, Ecological Process and Function Program

Partners: Oregon State University, Oregon Department of Fish and Wildlife


Thinning and slash treatments dramatically increase deer forage in older even-aged stands in Alaska


Use: Tongass National Forest uses vegetation data in new deer habitat model.

To improve the management of young-growth stands for multiple values, the station and Tongass National Forest established four operationalscale, widely replicated adaptive management experiments known as the Tongass-Wide Young-Growth Studies (TWYGS). A key goal of TWYGS is to assess the effectiveness of silvicultural treatments for improving forage availability for Sitka black-tailed deer, which is highly valued for sport and subsistence hunting and as prey for wolves and bears. In the fourth TWYGS experiment, thinning and slash treatments were applied to even-aged stands more than 35 years old. Five years after treatment, forage biomass in treated stands was four to six times greater than in untreated stands. Analysis of the biomass data with the FRESH-Deer forage availability model showed that treatments increased deer-days of forage availability by five times in summer and three to four times in winter, depending on the treatment.

The TWYGS experiments are the primary means for effectiveness monitoring of young-growth management under the Tongass land and resource management plan. The vegetation response data and outputs from the FRESH-Deer forage model are being used by the Tongass National Forest to develop a new deer habitat model for southeast Alaska. This new model will be used for project- and landscape-level planning.

Contact: Michael McClellan,, Focused Science Delivery Program

Partner: USDA Forest Service Tongass National Forest


Wolverine habitat projected to decline as climate warms


About 37 percent of current wolverine habitatis projected to persist through 2099 (Photo by John Rohrer).

Use: U.S. Fish and Wildlife Service uses findings in decision to list wolverine as a candidate species under the ESA.

The wolverine ’s range is confined to cold areas, typically arctic or alpine habitats, where relatively deep snow cover persists through the end of the reproductive denning period in mid-May. In the western contiguous United States, wolverine habitat occurs in an archipelago of alpine meadows and subalpine parklands that contain the climatic conditions necessary for their persistence. In that region, continued warming is expected to cause wolverine habitat to shift upward in elevation, decreasing both its geographic extent and connectivity. Consequently, understanding the potential effects of continued climate warming on the distribution, extent, and connectivity of wolverine habitat is essential for their conservation in the contiguous United States.

Researchers modeled the distribution of spring snow cover within the Columbia, Upper Missouri, and Upper Colorado River Basins. They projected that 67 percent of suitable wolverine habitat in the study area will persist through 2030–2059, but only 37 percent will persist through 2070–2099. Although large (>600 square miles) contiguous areas of wolverine habitat are likely to persist throughout the 21st century, such areas will become smaller and more isolated over time. Dispersal modeling indicated that by the late 21st century, habitat isolation will occur at or above levels associated with the genetic isolation of wolverine populations. These findings played a key role in the recent decision by the U.S. Fish and Wildlife Service to list the wolverine in the contiguous United States as a candidate species under the Endangered Species Act.

The lead scientist was interviewed by several media outlets, including National Public Radio and the Wenatchee World, Yakima Herald-Republic, and Methow Valley News, about this wolverine research.

Contact: Keith Aubry,, Ecological Process and Function Program

Partners: University of Washington Climate Impacts Group, USDA Forest Service Rocky Mountain Research Station


Population demography of northern spotted owls analyzes best available science


Barred owl (Photo by Wendy VanDyk, northern spotted owl, a threatened species under the Endangered Species Act, has become a well-known environmental symbol, and managing for the owl has been a complex issue for land managers. Station scientists collaborated with 27 owl researches associated with 12 institutions or agencies to produce a monograph that provides the most complete picture of the spotted owl’s population status to date. It assesses relationships between reproductive and recruitment rates and covariates such as habitat, weather, and the invasive barred owl. Population Demography of Northern Spotted Owls demonstrates how collaboration among scientists can provide an analysis template for species assessments and conservation.

The U.S. Fish and Wildlife Service used results from a draft version of this analysis when developing its Spotted Owl Recovery plan. With general release of the book, conservation biologists, federal and state land managers, and the public will have a clear picture of the current population status of northern spotted owls.

Contact: Eric Forsman,, Ecological Process and Function Program

Partners: Colorado State University, Green Diamond Resource Company, Hoopa Tribal Forestry, Olympic National Park, Oregon State University, Raedeke Associates, Inc., Simon Fraser University, USDA\APHIS National Wildlife Research Center, USDI Bureau of Land Management, Mount Rainier National Park, USGS Patuxent Wildlife Research Center For more information: Forsman, E.D.; Anthony, R.G.; Dugger, K.M. [et al.]. 2011. Population demography of northern spotted owls. Studies in Avian Biology No. 40. Berkeley, CA: University of California Press. 103 p.


Understanding barred owls habitat preferences may help northern spotted owl recovery


Interactions with barred owls are a leading cause of the northern spotted owls’ continuing decline in the Pacific Northwest. Substantial information on forest structure characteristics used by spotted owls has been collected over the past two decades, but little is known about forest structure characteristics used by barred owls. Understanding barred owls’ habitat preferences will help managers evaluate how forest restoration treatments in fire-prone forests may affect interactions between spotted owls and barred owls.

Station scientists used radiotelemetry to conduct the first extensive study of habitat use by barred owls. They learned barred owls use structurally diverse mixed grand fir forest more intensively than open ponderosa pine or even-aged Douglas-fir forest types within their home ranges in central Washington. The scientists shared their findings with the Barred Owl and Modeling Working Groups of the Northern Spotted Owl Recovery Team convened by the U.S. Fish and Wildlife Service. This information has contributed to recovery planning for the northern spotted owl.

Contact: Peter Singleton,, Threat Characterization and Management Program

Partners: USDA Forest Service Okanogan-Wenatchee National Forest, U.S. Fish and Wildlife Service


Study identifies causes for demise of sage grouse populations


Sage grouse (Photo by G. Kramer).

Use: Public and private land managers are using results to design and implement sage grouse recovery strategies.

Greater sage grouse populations in North America have declined for decades as their habitat has decreased. Station scientists examined how changes in land use could be contributing to these declines. They found that areas where local sage grouse populations had been eradicated had less sagebrush, were at lower elevations, were farther from power lines and communication towers, and were privately owned. Areas of extirpation were more often found along the periphery of the sage grouse range. Rates of habitat decline are increasing across large areas of western sage grouse range from continued and pervasive expansion of invasive plants and associated changes in wildfire regimes. Oil and gas development is also leading to habitat decline.

The scientists also measured the threshold values of sagebrush cover and elevation needed by sage grouse. These thresholds values are easily and accurately measured with existing spatial data across the range of the sage grouse.

The U.S. Fish and Wildlife Service used these findings when deciding if listing under the Endangered Species Act was warranted. The agency decided not to list the sage grouse and continues to negotiate changes in landscape management with other federal agencies to prevent future listings. This research provides the scientific foundation for these negotiations. These findings also are being used by private landowners and many different administrative entities that include county, state, and federal planning activities across western North America.

Contact: Michael Wisdom,, Ecological Process and Function Program

Partners: U.S. Geological Survey, Washington Department of Fish and Wildlife


Hope remains for polar bears’ sea ice habitat if greenhouse gases are reduced


No “tipping point” has been reached or is foreseeable for polar bear sea ice habitat over the next century, researchers determined. And, if global greenhouse gas levels are reduced, polar bear populations could be conserved or recovered. This work continues the research that led the U.S. Fish and Wildlife Service (USFWS) to list the polar bear as a threatened species in 2008. It provided new analyses on how several future greenhouse gas scenarios will likely affect polar bear sea ice habitat and populations. The analysis indicates that only major mitigation of greenhouse gasses will avoid sea ice loss and reduce the probability of polar bear populations becoming more vulnerable. It indicates that current sea ice loss resulting from climate change may still be reversible, providing new hope for conserving polar bears. This information can be used by the USFWS to help develop recovery actions for polar bears.

The research appeared as the December 2010 cover story in Nature.

Contact: Bruce Marcot,, Ecological Process and Function Program

Partners: National Center for Atmospheric Research, U.S. Geological Survey, University of Washington


Pacific walrus is vulnerable to continued loss of Arctic sea ice


Ice floes in the Artic Ocean north of Alaska. Global warming in causing ice floes to melt sooner inthe summer, forcing  walrus to haul out on land where they are more vulnerable to predation and have less access to food (Photo by Bruce Marcot)

Use: U.S. Fish and Wildlife Service uses study as basis for listing walrus as potentially threatened.

The Pacific walrus was recommended as a candidate for federal protection under the Endangered Species Act. Before making a final decision, however, the U.S. Fish and Wildlife Service (USFWS) needed more information on the potential viability of Pacific walrus populations, particularly under climate change and associated human impacts. To help inform that decision, a station scientist projected potential effects of climate change and other stressors on populations of Pacific walrus in the foreseeable future.

The findings were presented to the USFWS, which, as a result, reversed its previous draft finding not to list the Pacific walrus, and instead, listed the species as potentially threatened. This work also provides information on key stressors that could inform the USFWS recovery plan.

Contact: Bruce Marcot,, Ecological Process and Function Program

Partner: U.S. Geological Survey


Assessing habitat connectivity, land use, and climate gradients facilitates regional wildlife planning


Use: Washington Department of Transportation uses findings in statewide planning.

Many wildlife species need to be able to move across the landscape in search of food throughout the year. As human populations increase and more land is developed for human use, links between wildlife habitats are being lost. To address this, the Western Governors Association Wildlife Corridors Initiative and state wildlife action plans call for incorporating wildlife corridors into regional-scale, long-range landscape management planning.

To help with this process, station scientists worked as part of the Washington Wildlife Habitat Connectivity Working Group to assess regional habitat connectivity patterns for 16 focal species, natural landscape integrity connectivity patterns, and climate gradient patterns. The group completed a geographic information system (GIS) analysis of habitat conditions in the state, which can be incorporated into climate change adaptation connectivity planning. Station scientists provided technical guidance on model development and interpretation and facilitated technical peer review of modeling procedures and reports.

The Washington Department of Transportation is using the information and GIS data produced by the group in statewide transportation planning. The Washington Department of Fish and Wildlife also is using the information in planning efforts, and it is being used to develop decision-support tools under the Western Governors Association Wildlife Corridors Initiative.

Contact: Peter Singleton,, Threat Characterization and Management Program

Partners: Conservation Northwest; The Nature Conservancy; USDA Forest Service Pacific Northwest Region; USDI Bureau of Land Management; University of Washington; Washington Departments of Fish and Wildlife, Natural Resources, and Transportation; Western Transportation Institute For more information:





Equations for Evaluating Nutritional Quality of Available Moose Forage

Description: These equations for evaluating the nutritional quality of moose forages are based on laboratory analyses of small quantities of forage samples. Prior to their development, predictive equations for quantifying the nutritional quality of wild, native forages for moose in their natural habitats did not exist.

Use: Wildlife scientists and land managers can use these equations to quantitatively evaluate habitat for moose anywhere in the world.

How to get it: Spalinger, D.E.; Collins, W.B.; Hanley, T.A.; Cassara, N.E.; Carnahan, A.M. 2010. The impact of tannins on protein, dry matter, and energy digestion in moose (Alces alces). Canadian Journal of Zoology. 88: 977–987.

Contact: Tom Hanley,, Ecological Process and Function Program


New Model Predicts Marten Age Based on Genetic Material

Description: Researchers developed a Bayesian network model for predicting the age of martens based on chromosomal evidence and other environmental factors. This is the first model of its kind—calibrated and tested with empirical data—that can accurately predict a marten’s age by using hair samples or other genetic material collected without actually trapping the animal.

Use: Researchers can now estimate the population structure (number of animals by age class) solely from indirect evidence such as hair samples, rather than needing to trap and mark or biopsy individual animals. With further testing, such an approach could revolutionize wildlife field research of mammals.

How to get it: Pauli, J.N.; Whiteman, J.P.; Marcot, B.G. [et al.]. 2011. DNA-based approach to aging martens (Martes americana and M. caurina). Journal of Mammalogy. 92(3): 500–510.

Contact: Bruce Marcot,, Ecological Process and Function Program


Framework Facilitates Designing Effective Wildlife Corridors

Description: Wildlife populations in fragmented landscapes experience reduced gene flow, lose genetic diversity over time, and ultimately face greater extinction risk. Improving connectivity in fragmented landscapes is a major focus of conservation biology. Designing effective wildlife corridors for this purpose requires understanding of how landscapes shape gene flow. Station scientists developed a framework that uses expert opinion as a starting point and then systematically either validates the assumptions of expert opinion or identifies a peak of support for a new model more highly related to genetic isolation. This approach also accounts for interactions between variables, allows for nonlinear responses, and excludes variables that reduce model performance. Station scientists demonstrated its utility on a population of mountain goats inhabiting a fragmented landscape in the Cascade Range, Washington. Wildlife planners with the Washington Department of Transportation are using this tool to assess landscape connectivity along the I-90 freeway in Washington.

How to get it: Andrew Shirk,, Ecological Process and Function Program


US Forest Service - Pacific Northwest Research Station
Last Modified: Tuesday,18November2014 at14:53:04CST

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