Northeastern California has seen an increase in black bear (Ursus americanus) abundance over the last 25 years.  This population growth has led to increased human-wildlife conflicts near the town of Adin, just over 100 miles east of Redding near the California, Oregon, and Nevada borders.

In collaboration with Humboldt State University, the Integral Ecology Research Center, and the California Department of Fish and Wildlife (CDFW), SCI Foundation will help shed light on bear demographics in northern California.  Researchers intend to determine how black bears from Nevada and Oregon are entering the Warner Mountains inside the Modoc National Forest.  Bears are moving between multiple areas of suitable habitat, but we don’t know the location of wildlife corridors that make this movement possible.  Once established, this project could determine where possible harvest zones should be.


This project will assist CDFW in implementing responsible wildlife management strategies in the future by implementing  three methods of estimating black bear abundance: spatially explicit capture-recapture (SECR), multiple survey occupancy, and single survey occupancy.  Comparing the three methods will help researchers determine which method is the most cost-effective.  At the moment, single survey occupancy has been useful in determining migratory bird abundance inexpensively and efficiently, however it has not yet been applied to large mammals such as bears.

Once the initial estimates of black bear sex-ratio and abundance are made using all three methods, the second objective will be to provide the first estimates of black bear spatial variation across the study area. CDFW will then determine from these estimates if there are enough bears to warrant a hunting season, and where harvest boundaries should exist.  Using the best available science to guide management, bear hunting in northeastern California could be reopened for the first time in decades.

California Black Bear Hair Snare Areas USFWS Photo 2017

The third objective of this project will be to collect and build a database of black bear DNA.  Researchers will then reference this database to determine if northeastern California black bears are primarily local, or emigrants from other populations in nearby states. Hair snares have proven to be the most cost-efficient and least invasive method of collecting bear DNA.  Five primary grids of 20 contiguous hair snare grid cells will be placed strategically throughout the study area.

The final objective will be to recruit and provide training to at least 10 local community members, primarily hunters, to assist with survey activities.  The project will benefit by gaining additional field support by those who know the area, as well as empowering the local community to manage and benefit from their own natural resources.  Dr. Jared Duquette, who previously worked with SCIF on the Michigan Predator-Prey Project, will be leading this project and its community outreach components.  This volunteer opportunity will maintain a positive working relationship with hunters, the local public, private, academic, and tribal groups, which will foster good relations between the community and the state on black bear management.


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