Black Bear Population Estimates (1992 - 2012) Click on the map to view a larger size
California's black bear population has increased over the past 25 years. In 1982, the statewide bear population was estimated to be between 10,000 and 15,000. Presently, the statewide black bear population is conservatively estimated to be between 25,000 and 30,000.
Two subspecies of black bear are recognized in California, the northwestern black bear (Ursus americana altifrontalis) and the California black bear (U. a. californiensis). The subspecies are thought to be geographically distinguished by the crest of the Klamath Mountains. Differentiation between distinct black bear "populations" is difficult in California, even at subspecies level, because there are no significant barriers restricting bear movement between occupied habitat. However, differences in vegetation, water availability, and bear density, allow biologists to differentiate three regional "subpopulations" of black bears in California-North Coast/Cascade, Sierra, and Central Western/Southwestern.
The North Coast/Cascade subpopulation occurs north and west of the Sierra Nevada Mountains and includes both the Northwestern and Cascade floristic provinces (Jepson 1993). Roughly half of the statewide black bear population resides in this portion of the state. Previous and ongoing studies indicate that bear densities range from 1.0 to 2.5 bears per square mile (Department of Fish and Game 1993, Kellyhouse 1977, Piekielek and Burton 1972). Almost all of the bear habitat in this area is publicly owned or used for timber production. Large wilderness areas are located in each of the National Forests of this region.
The Sierra Nevada subpopulation encompasses the Sierra Floristic province (Jepson 1993) and extends from Plumas County south to Kern County. Black bears inhabit the entire region. Forty percent of the statewide black bear population inhabits the Sierra Nevada Mountains. Bear Populations are less dense in the Sierra with between 0.5 and 1.0 bears per square mile (Grenfell and Brody 1983, Koch 1983, Sitton 1982). Over two-thirds of the bear habitat is administered by the U.S. Forest Service and two large National Parks are located within this region.
The Western/Southwestern subpopulation extends south and east from Santa Cruz County to San Diego County. Prior to 1950, black bears were not believed to inhabit the Central Coast or Transition Ranges (Storer and Tevis 1978, Hall and Kelson 1959 Grinnell et al 1937) where black bears were believed to be excluded or limited by the larger California grizzly bear (Ursus arctos californicus). After the California grizzly bear became extinct around the turn of the century, black bears started to appear in Ventura and Santa Barbara Counties (Grinnel et al 1937). The Department of Fish and Wildlife supplemented this natural range expansion by moving black bears into southern California during the early 1930's (Burgduff 1935). The current black bear population in the San Gabriel and San Bernardino Mountains is believed to be at least partially descended from this supplemental introduction.
Probably less than 10 percent of the statewide black bear population inhabits the Central Western/Southwestern California bioregion and bears are restricted to the Central Coast and Transverse Mountain Ranges. In the Central Western province, bears were detected by bait stations with decreasing frequency as latitude increased (Schultz 1994). Based on studies of black bears in Chaparral habitats in Arizona (LeCount 1982) and southern California (Stubblefield 1992, Novick 1981, Moss 1972) bear density is probably less than 0.25 bears per square mile.