Kio, a 390-pound grizzly, is trying to break into a 30-gallon cooler. She’s rolled it over, gnawed on the plastic, and tried to pry open the lid with her claws.

When Kio loses interest in the cooler, Peeka⁠—a subordinate female⁠—moves in for a turn. But Kio growls possessively. The bears snarl and engage in body bluffing before Peeka slinks away.

“Peeka was like, ‘Cool, sister. I’m going to steal this,’” says Chelsea Davis, animal care facilities manager at the Washington State University Bear Research, Education, and Conservation Center. “But Kio came back with, ‘I wasn’t through.’”

“That’s why I test coolers with two bears,” Davis adds. “There’s jealousy; there’s competition.”

WSU grizzlies frequently contribute to science. Researchers study them to learn about bear behavior, nutrition, habitat needs, and the physiological changes that occur during hibernation.

This year, the bears are collaborators in a new project⁠—testing coolers for manufacturers.

For manufacturers to earn “bear-resistant” certification from the Interagency Grizzly Bear Committee, their cooler designs must withstand a full hour of bruin contact or pass a technical evaluation.

Most of the testing takes place at the Grizzly and Wolf Discovery Center in West Yellowstone, Montana, where captive bears have been mauling coolers in the name of research for nearly two decades. But recently, the thrill started wearing off.

“Those bears were getting burned out,” Davis says. As their interest waned, the bears put less effort into breaking in, creating a backlog of untested product.

Enter WSU’s bear center. Manufacturers pay a fee for the testing and send their designs to the Pullman center, where the grizzlies have responded enthusiastically to the coolers Davis packs with bait.

“We want something smelly, something noisy, and something familiar from their diet,” she explains, tossing two sausages, a handful of apples, and bear kibble into the cooler. The bait gets drenched with honey water before Davis secures the cooler’s padlocks. “It leaks out and keeps their interest.”

“[A bear is] basically a mouth on legs,” says Heather Havelock, a WSU graduate student who works at the bear center. From spring through fall, they’re packing on pounds.

Grizzlies have insatiable appetites during hyperphagia, the weeks leading up to hibernation. Kio and Peeka look lanky in early July but will bulk up to 450 pounds before they hibernate. For wild bears, coolers represent a potentially easy food source.

The Pullman community donated about 60 picnic coolers to the bear center to train WSU grizzlies to associate coolers with food. The average break-in time is two to three minutes.

“Their teeth go through regular plastic like butter,” Davis says. “If you stored fish in a cooler six months ago, they’re still going to smell it.”

The sturdier coolers sent for testing pose more of a challenge, and break-in methods vary by gender.

Male grizzlies hurl coolers to the ground, attempting to smash their way in. Females spend more time with the coolers, trying out different techniques.

At one point, Peeka got control of the cooler and climbed on top of it. If the plastic cracks, bears will apply CPR-like pressure to enlarge the opening so they can rip apart the container.

The bears spent about 20 minutes trying to break in before they lost interest. Davis checked the cooler for damage, finding scratches, bite marks near the locks, and some give in the outer wall. She’ll retest the container later with different bears. If the inner walls remain unbreached during 60 minutes of bear contact, the cooler’s design can qualify as “bear resistant.” That makes the product a good option for a backcountry trip.

Through the testing, WSU grizzlies are helping wild bears stay out of trouble. Once bears become habituated to human food, they lose their fear of people. Many are captured and put down or relocated.

Four of the grizzlies at the bear center came from conflict situations, Davis says. Two were cubs who picked up bad habits from their mothers.

Nine WSU grizzlies took part in testing coolers this year. Besides the value of the product research, “we think of this as an enrichment activity for our bears,” she says.


Web exclusive

Video: WSU grizzlies attempt to open a cooler  (Video produced by Ted S. Warren/WSU College of Veterinary Medicine)


Read more

The Bear in Your Back Yard: Throughout North America, they’re showing up in unexpected places. Can we coexist? (The New Yorker, July 17, 2023)