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Native Californian, biologist, wildlife conservation consultant, retired Smithsonian scientist, father of two daughters, grandfather of 4 small primates. INTJ. Believes nature is infinitely more interesting than shopping malls. Born 100 years too late.

Wednesday, September 1, 2010

Chimineas' black bears -- descendants of pioneers

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.

2 comments:

Anonymous said...

In '92 my folks rented a houseboat at Shasta lake. we spent the week with them, with our then 8 year old. On our last night, we tied up to a tree on the shore. About 2am, my dad, then 80 and recovering from angioplasty, woke us up with the news that there was a bear on the boat! We went forward and sure enough, there was a very large cinnamon colored bear in the garbage can on the front deck. We were tied up in very deep, cold water, with no safe egress and were only separated from the bear (which looked about the size and shape of the grizzlies we had seen in Alaska) by a sliding glass door. Noise and yelling didn't do any good and after he finished the cake I had brought for father's day, the bear looked way too interested in what might be in with us. John finally decided to call the bears bluff, with the rest of us poised to take our chances in the lake. John gingerly opened the door and pounded on the deck with a plastic patio chair. The bear gave us a long look and went back over the rail to the hillside. We still have the cardboard cake disc perforated by the bears canines as a souvenir. No doubt, we were very lucky! The funny thing is, that I had commented that "good thing we were going to be on a boat as I draw bears {I do- there are bears wherever I go}". So there's my bear story- never occurred to us that a bear would look at a houseboat as a floating cafeteria, but in retrospect, why not?

Britta Hald

Camera Trap Codger said...

Glad the post brought back some bear memories that had a happy ending.