NOROCK Large Carnivore Research Program

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NOROCK has substantial expertise in large carnivore research, primarily involving species listed as Threatened or Endangered.  NOROCK’s Large Carnivore Research Program includes scientists from NOROCK’s Headquarters, West Glacier Field Station, and the Southern Appalachian Field Station.  Studies are conducted in a wide variety of landscapes throughout the U.S., as well as international research collaborations.  The Large Carnivore Research Program is focused on 1) bear ecology and management, 2) ecological restoration, 3) diseases of predators, and 4) development of analytical tools. 

Mother grizzly and cub at Gibbon River, Yellowstone National Park.

A USGS grizzly bear researcher snapped this picture of a mother grizzly bear and her cub in Yellowstone National Park. Adult females are the most important segment of the grizzly bear populations because they are the reproductive engine.

Bear Ecology and Management:  The Interagency Grizzly Bear Study Team (IGBST) is an interdisciplinary group of scientists and biologists whose main objectives are to monitor the status and trend of the grizzly bear population in the Greater Yellowstone Ecosystem (GYE) and determine patterns of habitat use by bears and the relationship of land management activities to the health of the bear population.. The team, led by USGS, includes representatives from the National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, the Eastern Shoshone and Northern Arapaho Tribal Fish and Game Department, and the States of Idaho, Montana, and Wyoming. A recent food synthesis analysis addressed grizzly bear responses to changing food resources.  Findings suggest a paradigm shift away from dependence on whitebark pine to the dynamic ability of grizzly bears to use a wide variety of food resources, depending on their availability in space and time. These data were used to inform policy decisions, including a recommendation by the Interagency Grizzly Bear Committee that the U.S. Fish and Wildlife Service produce a new proposed delisting rule.  As required by the ESA prior to any delisting decision, the U.S. Fish and Wildlife Service reviewed the best available scientific information, much of it based on the food synthesis analysis and other IGBST studies. 

Huckleberries are central to the diets of bears, grouse, and other animals, as well as being a cultural and food resource.

Huckleberries are central to the diets of bears, grouse, and other animals, as well as being a cultural and food resource for humans. 

In northwestern Montana, NOROCK scientists at the West Glacier Field Station conducted the largest genetic-based study of population size and trend for grizzly bears from 2004-2012.  They then constructed a grizzly bear family tree based on the genetics to learn how dispersal and reproductive patterns influenced genetic diversity and to assess whether conflict behavior is passed down from mother to offspring. Building on this family tree, the next objective is to create a map quantifying where bears are most likely to disperse for use in conservation planning and mitigating for highway effects on bear movement.  Scientists have also begun pilot work for a study on huckleberries, an important bear food, seeking to create a predictive map for the location, number, and timing of huckleberries across site conditions and weather.  This tool will help managers prioritize places where conservation and management may improve the consistency and number of huckleberries available for wildlife.   As a way to collect data on huckleberry growth and pollinator presence, NOROCK scientists in collaboration with the Fort Collins Science Center developed a phone app that functions similar to geocaching applications and can be used by any scientist to facilitate citizen science. 

Recent research at NOROCK’s Southern Appalachian Field Station involved a comprehensive population assessment and viability analysis of the Louisiana black bear.  This subspecies of the American black bear was listed as a federally threatened species in 1992.  Over 10 years of research indicated that the long-term viability of the Louisiana black bear population was high and based on these findings the U.S. Fish and Wildlife Service removed from the Endangered Species List in March 2016.  Most recently, scientists led a study to obtain a statewide, spatially explicit population estimate for bears in Florida, which included DOI and other federal and state lands.  The data from this project were the basis for a decision by that state of Florida to reinstitute a black bear hunting season in 2015. 


Black Bear and Cub in Montana

This is a black bear and cub in Montana.

Ecological Restoration:  Research at NOROCK’s Southern Appalachian Field Station has been focused on ecological restoration.  Past projects include an evaluation of the effects of deer and feral hog hunting on the behavior of the federally endangered Florida panther and an in-depth assessment of prospective panther reintroduction sites.  In a collaborative study with the National Park Service, reintroduction of elk into Great Smoky Mountains National Park in North Carolina and Tennessee was closely monitored, including a population viability analysis to predict population growth and identify limiting factors.  Calf survival was found to be an important determinant of population growth and results from a follow-up study indicated that predation by black bears contributed to low calf survival.  On the Cumberland Plateau of Tennessee and Kentucky, scientists developed methods whereby denning adult female black bears and their cubs were moved from Great Smoky Mountains National Park to the Big South Fork National River and Recreation Area.  A subsequent study showed that the bear population had increased from 18 in 1998 to 190 in 2012.  Using the winter den release method, scientists reintroduced black bears were to Felsenthal National Wildlife Refuge in Arkansas and to the Three Rivers Complex in Louisiana.  Genetic results indicate that those reintroductions have greatly increased movement and interchange between the isolated and fragmented bear populations in both states.  


Comparison of traditional and thermal imagery to show mange.

Thermal imagery is one tool to assist researchers in measuring temperature loss from the mange patches (red) and compare this with temperature loss from natural fur (blues and greens). As you can see in the two contrasting images, the hairless areas associated with mange are much easier to see using thermal imagery due to heat loss versus a standard photograph from a remote camera. Public domain

Diseases of predators Scientists at NOROCK have been studying the effects of disease such as canine distemper virus (CDV) on wolves and bears for the past 8 years. Although diseases seldom lead to host extinctions, they are often contributing factors. CDV is potentially the most important disease of predators worldwide as it infects most carnivore species and is widely distributed. Periodic CDV outbreaks in wolves result in large pup loses in the year of the outbreak and are currently unpredictable. As a result, CDV can increase the variation in wolf populations, which is one of many issues to consider in setting of hunting and trapping quotas for wolves in the Northern Rocky region. NOROCK researchers have also worked with collaborators in Chile and Russia on potential vaccination of dogs and wildlife for CDV. In addition to CDV, researchers at NOROCK have worked on the effects of Sarcoptic mange in wolves since its introduction into Yellowstone National Park in 2007. Using a combination of field research and citizen science efforts, scientists have discovered that although mange seldom kills wolves directly, it is a predisposing factor, and those survival impacts seem most severe in the smallest packs. This suggests that carnivores in larger packs can sometimes provide a social safety net for infected individuals when they are sick. Recent work used thermal imagery to estimate the calorie costs associated with mange infections of wolves in the winter.


Researcher tracking grizzly bears using telemetry in Wyoming.

Researcher tracking grizzly bears using fixed wing telemetry in Wyoming.

Development of Analytical Tools:  Scientists in NOROCK’s Large Carnivore Research Program integrate spatial ecology, conservation biology, genetics, and statistics to answer applied management questions related to 1) identifying wildlife movements, distributions, and interactions in response to humans, land use, and climate across multiple scales; 2) developing new analytical tools to study the influence of habitat and human activity on animals; and 3) improving efficiency of research and monitoring through optimal study design.  In Alberta, for example, scientists studied spatial capture-recapture designs for estimating the size of a small population of grizzly bears.  This work showed that robust results were possible with a less expensive sampling design.  In Florida, scientists developed a study design for DNA-based population studies of black bears using sampling arrays.  These arrays consisted of a small cluster of DNA sample sites, but distributed over very large areas.  Study findings showed that reliable population estimates can be obtained in a cost-effective manner.  In the GYE, scientists developed advanced tools to identify grizzly bear visitation and use of ungulate carcasses based on location and activity data from satellite GPS collars.


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