Wildlife migrating to people centers

Dec 10 2012 - 6:29pm


Suburban deer
Suburban deer


At Foothills Park in Palo Alto, Calif., a mama deer and her family emerged from the woods and grazed in the meadow just beyond a crowded picnic area. They paid no mind to the dozens of onlookers.

In Marin County, on the slopes of Mount Burdell at Olompali State Park, many hikers had similar encounters. A multitude of deer, almost tame, were everywhere.

Yet on the western slopes of the high Sierra, you could go days and never see a deer.

In Yosemite Valley last summer, the combination of many bears scrounging for food and speeding cars on the park's roads resulted in 17 bears hit by cars. Last year, there were 19. Yet outside the park in wilderness on the Pacific Crest Trail, you could hike for weeks and never see a bear.

Landmark changes in wildlife behavior in the past 25 years, caused by a variety of reasons, are transforming the scope of the outdoors in California.

-- The "suburban deer": A GPS collar tracking survey in the Bay Area and Sierra foothills found that most deer in California live their entire lives within a 5- or 6-mile radius. They are prolific at parks, golf courses and the yards of sprawling homes that adjoin open space areas. These deer are virtually domesticated and bear little resemblance to the mountain-bred mule deer of the northern part of the state that migrate according to weather and snow lines.

-- Sierra Nevada/Cascade deer: Gone are the great herds of wild deer that once migrated every fall from the high Sierra and Cascade ranges to their wintering grounds in the foothills. Best estimates say the number of deer in California has plummeted from 2 million in the 1960s to about 450,000 (of which most are "suburban deer"). Expanded highways and new subdivisions have blocked historic migration routes. Timber companies cut down forests and replanted them with conifers, which deer can't eat, so there's less food. Record-high populations of mountain lions eat a deer or two per week.

-- Mooching bears: Bears go where there's easy food and away from where they might get shot. That's why there are so many in Yosemite Valley around the campgrounds -- even when there are 15,000 people in a 2.5-square-mile area on a summer day -- or along Highway 198 in Sequoia National Park. In areas like the Golden Trout Wilderness, where people are few and those few use bear-proof canisters for food, the bears head elsewhere for easy pickings.

-- Ducks: Back in the day, deep in a marsh in the Sacramento Valley, you could witness spectacular dawn fly-outs of waterfowl. The ducks would wake for the day and depart en masse from resting areas in the marsh to feed at nearby rice fields. No more. Ducks have become largely nocturnal in the Sacramento Valley. They feed at night and then predawn, before shooting time, they return to the marsh to sleep or fraternize with other ducks in protected no-hunt zones.

-- Striped bass: Forty-four years of pumping has turned the Sacramento-San Joaquin River Delta upside down. The pumps suck down 70,000 gallons of water per second and send it to points south, and with it go juvenile fish and eggs. Striped bass once spawned in great numbers, roughly 4.5 million adults, in the delta and associated waterways. They're all about gone.

(Reach Tom Stienstra at tstienstrasfchronicle.com. Distributed by Scripps Howard News Service, www.shns.com.)


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