Studying black bears in Washington? Use cow blood and fish oil

Carrie Lowe, a Washington Department of Fish and Wildlife assistant district biologist, pours a foul-smelling concoction of cow blood and fish oil onto a pile of logs in Northeast Washington on July 23. The effort is part of survey of bears throughout the state aimed at gathering regional density information.

On a sunny Tuesday morning in the mountains of the Colville National Forest, all was quiet except for a steady glug glug as Carrie Lowe poured an evil-smelling concoction of cow blood and fish oil over a pile of logs.

The vicious (and viscous) brew had sat for months, fermenting in the heat, finally gaining an olfactory power up to the current task: luring bears over parallel strings of barbed wire strung between four trees.

The effort is part of a larger statewide study aimed at determining bear densities in different regions of Washington.

That information has never been collected in Washington, with managers instead using notoriously unreliable hunter harvest reports and decades-old statewide population estimates to set hunting regulations.

“We’ve never done area-specific density estimates,” Lowe says.

With only 20 percent of hunters submitting teeth from their bear hunts, Lowe called the current system “really unreliable.”

“We really have very little idea of what’s being harvested,” she says. “Most other states have gone to some sort of harvest management based on density.”

Due to competing projects and limited money, the study is being conducted in two or three regions each summer. This year, Region 1 and Region 6 are on the docket.

On July 23, Lowe, a Washington Department of Fish and Wildlife assistant district biologist, Leslie King, a habitat biologist and Staci Lehman, a spokeswoman for the agency, checked traps set in Game Management Unit 117, near Chewelah.

This is how it works: The bears follow the smell of the bloody cocktail to the study site. (Although black bears’ diets are about 95 percent berries, nuts, fruits, flowers and roots, they are equal-opportunity eaters and will consume meat when available.)

There, they see a pile of logs that looks awfully similar to a food cache. They approach, digging through the logs looking for a snack, which they won’t find. But to get to the delicious smelling pile they have to step over, or crawl under, the two strings of barbed wire. As they do that, they leave samples of their hair behind (the barbed wire does not hurt the bears).

The biologists check the traps every 10 to 14 days, collecting any hair samples left. Those samples are then be sent to a lab in British Columbia for a DNA analysis, says Lindsay Welfelt, a statewide bear and cougar specialist overseeing the study. Those results give biologists a sense of how many bears they’re dealing with. That information is then used to gather a regional density estimate.

“Our first priority really is having a better idea of what our statewide population is,” Welfelt says. “We don’t have an estimate right now, so it’s hard to gauge our harvest rates.”

By doing it regionally, biologists will get a better sense of how bear densities vary depending on habitat, human proximity and other factors.

The project started in 2013 in the western Cascades, Welfelt says. Since the 1970s, wildlife managers believed there were higher densities of black bears in the western Cascades than in the eastern Cascades or eastern Washington. Researchers thought the abundance of rain and vegetation west of the Cascades made for better black bear habitat.

But the 2013 study proved that assumption wrong.

“We were finding that the density in our western Cascades was about half as much as what we thought it would be,” she says. “And it was primarily impacted by human development.”

Those findings will be published in the next few weeks in the Journal of Wildlife Management, Welfelt said.

“Our findings underscore the importance that black bear density is not likely uniform and management risk may be increased if an average density is applied at too large a scale,” states the studies abstract.

Biologists finished collecting samples in northeast Washington this week ahead of black bear hunting season, which opened Thursday.

The sampling effort, including the DNA testing, costs around $50,000 per year, Welfelt said. The barbed wire sampling method is much cheaper than capturing black bears and fitting them with a GPS collar.

Last week, in the woods of northeast Washington, Lowe, King and Lehman checked several trap sites, high-stepping over downed trees on steep, rugged terrain. In addition to pulling samples of hair, they also check game cameras placed near the traps.

Those images help biologists determine whether multiple samples are from the same bear or not.

It’s a tremendous amount of work, with individual strands of hair having to be gently pulled from the barbed wire using tweezers and then placed in bar-coded manila envelopes.

The entire tableau underscores the occasional tension between science and wildlife management decisions made for political or social reasons.

That’s because on July 1, the Washington Fish and Wildlife Commission simplified black bear hunting regulations, opening the season statewide on Aug. 1 and allowing hunters to kill two bears anywhere in the state. Previously, hunting had opened later in eastern Washington and hunters could only kill one bear from the east side of the state.

Although wildlife managers recommended the change, Welfelt said the recommendation did not come from her and was not based on any research she’s done.

“We understand trying to make things simpler, for sure. Because we do hear a lot from the public that they want things to be simpler,” she said. “But it’s kind of unknown what affect that will have on the population at that point.”

She doesn’t anticipate the rule changes will impact the ongoing study. The influence of those kinds of social pressures was highlighted in a 2018 study that found that national hunting rules and policies are largely not based on science. At the time, department officials said that they consider public opinion, history, other social factors and science when making management decisions.

As the state and others consider the complicated social landscape of big-game management, biologists like Lowe will continue to do the steady, meticulous and sometimes smelly work of wildlife science.

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