Population Dynamics and Habitat Relationships of Black Bears and Grizzly Bears in the Northern Rocky and Appalachian Mountains

Sow grizzly bear with cubs in Yellowstone National Park.

Predators such as Grizzly Bears and wolves are icons of the rugged American West, and yet remain misunderstood and are often feared by the general public. Grizzly bear populations in the continental United States were listed as “threatened” under the Endangered Species Act in 1975. NOROCK scientists have been studying grizzly bear populations in the Greater Yellowstone ecosystem for over 30 years and for over a decade in the Northern Continental Divide Ecosystem. Scientists have used radio collars to track grizzly bear movements, monitored habitats and key foods, and most recently have developed non-invasive hair snaring techniques to genetically identify individual bears and to estimate population size in the Northern Continental Divide ecosystem. This work has been done under the guidance of the Interagency Grizzly Bear Committee (IGBC), which includes representatives from various state and federal agencies and NGO’s. The IGBC meets regularly to review management policies, monitor the success of bear recovery efforts, and determine future research needs. USGS scientists, as part of interagency working groups have provided valuable scientific information in support of the recovery and de-listing efforts undertaken by management agencies. Science conducted by the Interagency Grizzly Bear Study Team, led by USGS scientists, has provided the foundation for the current de-listing proposed for the Greater Yellowstone. Similarly, science provided by the USGS Northern Divide group will provide a credible, defensible population size that is the initial benchmark for the NCDE. Detailed information about this work is available by clicking on the project links below.

Current Projects

Additional Links to Bear Information

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