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A descendant of the black bears that pushed the frontier into California's Central Coast Range. |
Before the demise of our late and great state mammal -- the Grizzly -- black bears didn't trod the trails of the Chimineas Ranch.
The two bears coexisted in much of pre-over-developed California, but not in the Central Coast Range.
Nor were black bears found in in the Central Valley, the Los Angeles basin, and the San Francisco Bay/Delta region where Grizz reined supreme.
Something about those exclusively Grizz areas was unsuitable for black bears.
The smaller bear couldn't compete with the big bear for food, and in sparsely treed areas, it couldn't climb out of the Grizzly's reach when there were altercations.
Well, those are the hypotheses.
Before the last Grizz died in the 1920s however Joseph Grinnell noted that black bears were starting to show up in the mountains of southern California.
The Department of Fish & Game approved of the immigrant bears as a tourist attraction, and in the 1930s lent a helping hand by capturing and moving 28 black bears from Yosemite to the San Gabriel and San Bernardino mountains.
Recently Sarah Brown and colleagues at UC Davis, Cal Fish & Game and the US Fish & Wildlife Service examined the molecular genetics of 540 California black bears to better understand their relationships and history.
They found that California's black bears fall into 4 major groups based on population genetics.
The North Coast/Klamath bears are the most genetically diverse, while the southern Sierra Nevada/ Central Coast population are the least diverse, though still within the range of genetically healthy populations elsewhere in the US.
Depending on analysis Sierra Nevada black bears fall into 2 or 3 genetic clusters along the mountains 650 kilometer length.
Pioneering bears of the Sierra Nevada invaded the exclusive domains of Grizz in Southern California and the Central Coast Range.
Southern California bears, the descendants of pioneers and translocated animals resemble bears of the Central Sierra Nevada.
Central Coast Range bears, including the bears of the Chimineas Ranch and Carrizo Plains are genetically related to the bears of the Southern Sierra Nevada.
That bear at the top of the page has no idea of its ancestors who forsook the Sierra Nevada for the hot summers and rainy winters of the central coast.
Come to think of it, I know as much about my own ancestors.
[
Nota bene: the young bear above was camera trapped on the Chimineas Ranch in July, 2010. The photo is uncropped.]
References
Brown, S.K., J.M. Hull, D.R. Updike, S.R. Fain, and H.B. Ernest. 12009. Black bear population genetics in California: signatures of population structure, competitive release, and historical translocation. Jounral of Mammalogy, 90(5):1066-1074.
Grinnell, J., J.S. Dixon, and J.M. Linsdale. 1937. Fur-bearing mammals of California. University of California Press, Berkeley
Storer, T.I. and J. Tevis. 1996. California grizzly. University of California Press, Los Angeles.