Tracking bears by their hair in SLO County

Using a network of 54 stations set up across eastern San Luis Obispo County, biologists are gathering a cache of hair samples, which will be genetically analyzed at UC Davis to provide a comprehensive profile of the area’s black bear population

dsneed@thetribunenews.comJuly 28, 2013 

High in the La Panza range of eastern San Luis Obispo County, wildlife biologists climb out of their dusty pickups and approach a bizarre barbed-wire enclosure in a stand of blue oaks.

The powerful stench of rotting flesh emanates from a pile of sticks in the middle of the enclosure. Incongruously, the sweet smell of honey wafts from a tampon dangling from a string 8 feet above the stick pile.

The biologists set to work examining every inch of the barbed wire. Soon, they find what they are looking for — a tuft of bear hair snagged on one of the barbs.

The tuft is carefully removed from the wire and placed in a small envelope. It will be sent to a laboratory at UC Davis for genetic analysis.

This and dozens of other hair samples collected over nine weeks this summer will give biologists an unprecedented, detailed picture of the county’s thriving black bear population and what it means for public safety.

“This is the first largescale genetic sampling of black bears in the state that we’ve ever done,” said Marc Kenyon, coordinator for the state Department of Fish and Wildlife’s black bear program.

The program began in late June and will conclude in August. A similar study will be done in the fall in Monterey County.

When the study is complete next year, wildlife managers will have a much more accurate idea of how many bears live in the county and where. The data will also form a baseline for tracking trends in the population.

Bears are a beloved wildlife species in the county, but they can cause problems for humans. The bear population is expanding, and bears are beginning to show up in places where they have never been seen before.

Here are a few examples:

• Two weeks ago, a bear was hit and killed by a car as the animal crossed Highway 101 just north of the Cuesta Grade. This is a particularly dangerous stretch of highway for both bears and drivers.

• Bears are attracted by the easy picking they find in orchards, farms and backyards. Bears that become in the habit of seeking out these food sources can cause considerable property damage and be a danger to public safety.

• A bear recently was spotted at locations along the coast from Point Buchon to Morro Bay, areas where the animals are not normally seen. It was eventually captured at Morro Rock and relocated to the Los Padres National Forest.

Additionally, in 2010, the state Fish and Game Commission turned down a proposal to allow bear hunting in San Luis Obispo County, saying the department needed more time to study the bear population before a hunt could be approved.

Biologists say the genetic study will help them manage the bears and minimize these conflicts. Wildlife managers hope the genetic study on the Central Coast will allow them to get ahead of the challenge of managing bears before they become a more serious problem, as they have in such places as Lake Tahoe and Mammoth Lakes.

"Understanding this expanding population will help us make informed planning decisions that are in the best interest of bears,” Kenyon said.

Where to look

The Department of Fish and Wildlife began the study by mapping the interior of the county for suitable bear habitat. Ideal bear habitat is oak woodland interspersed with stands of manzanita. Acorns and manzanita berries are prime sources of food for bears.

Biologists then picked 54 accessible locations on private land or in Los Padres National Forest as sites for the sampling stations, or corrals, as the biologists call them.

Each corral consists of two strands of barbed wire forming an enclosure of 10 or 15 feet across. One strand is about a foot off the ground, and the other is about 2 feet high.

A large pile of dead sticks is placed in the center of the corral. Two bottles of stinky fermented fish and steer’s blood is poured over the pile. A tampon soaked with concentrated honey, raspberry or anise scent is suspended about 7 or 8 feet above the sticks.

These traps depend on a bear’s acute sense of smell. A bear can detect food from as far as three miles away, biologists say.

The sweet scent from the loftily positioned tampon will be carried long distances by the wind, and is liable to attract the bear’s attention first. Sensing food, the bear will investigate and soon catch wind of the scent of the blood and fish bait.

The bear is liable to think that the pungent pile of sticks is where a mountain lion or another bear has cached a carcass. The bear will squeeze between the strands of wire to investigate this possible easy, high-protein meal, leaving behind hair samples as it enters and exits the corral.

Biologists visit each of the 54 traps once a week to collect any hair samples snagged on the wire and to refresh the bait scents, said Bob Stafford, DFW biologist assigned to San Luis Obispo County.

The baited corrals were designed to have as little impact on the bears as possible. The barbed wire does not injure the bears, and the corral contains only scent and nothing the bears can actually consume so the bears are not liable to change their foraging habits due to the bait stations.

Once the hair samples arrive at the UC Davis Wildlife Genetics and Population Health Lab, they will be subjected to DNA testing and analysis. Lab technicians will concentrate on the hair follicle, the tiny skin sac from which the hair grows.

The DNA analysis will allow biologists to identify individual bears and determine whether they are related to one another, as well as detect breeding trends and insights into their movement patterns.

“It’s impressive that we can get that much genetic information from such a tiny, tiny sample,” said Jamie Sherman, a graduate student at UC Davis who is helping with the DNA analysis.

The bear study in San Luis Obispo County cost $95,000. A federal wildlife grant covered 80 percent of the cost, with state funds from hunting license and tag fees paying for the rest, Kenyon said.

See more photos of the bear-tracking team at work »

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