On private property near Kings Beach, a bear we will, for the purpose of this article, call “Yogi,” is trapped inside a brown California Department of Fish and Wildlife pen after loitering around a trash compactor. Yogi viciously lunges at people who get too close, letting out a powerful, gargling huff of rage. Fish and Wildlife bear biologist Mario Klip, who captured the beast, opens the cage and, despite the barking dogs he is holding, the confused bear does not leave until someone jabs it with a stick, sending it racing out, the dogs hot on its tail and nipping its hind-quarters. It blasts across a stream, so startled it leaves a trail of diarrhea behind, and claws up a tree to escape.
This is called aversion conditioning, the key tool for Nevada and California wildlife managers as an alternative to killing problem bears. The goal is to train a bear to associate people and garbage with a bad experience so that it doesn’t come back. But past and present research into the effectiveness is contradictory; one study claims that the technique is unsuccessful 92 percent of the time, and is more successful as a public relations campaign to educate people to stop leaving trash around for bears.
A 2010 study published in the Journal of Wildlife Management by Rachel Mazur shows that aversive conditioning in Sequoia National Park worked for bears that were not conditioned to eating human food. Of 29 bears that did regularly eat human food, nearly two-thirds abandoned their love of garbage after the conditioning.
However, that research was done in an area where there aren’t neighorhoods full of people and unsecured garbage like Lake Tahoe. Regardless, managers like Klip are hoping some of Tahoe’s bears can be saved with the conditioning.
“We are focusing on animals that are not habituated to people and not habituated to garbage,” said Klip. But even that can be hard to tell. “Well, you don’t know for sure if it is a garbage bear or not. A bear this time of year will not pass up the opportunity for a nice snack.”
Nevada and California’s tactics of aversion conditioning differ slightly. Nevada releases bears far away from where they were caught digging into garbage, while California releases the problem bears right where they were captured.
“We pretty much don’t do it (relocation) at all here in Tahoe because of the fact that they come back,” Klip said.
However, a 2002 University of Nevada, Reno study shows that aversion conditioning in the Tahoe area doesn’t work at all.
“Our analysis revealed that 92 percent of the time, black bears exposed to deterrents returned to the urban patch,” wrote Jon Beckmann in the 2002 study. The “objective will most likely always be met with failure,” and that deterrents may be an effective management tool “if the goal is to establish positive public relations,” he wrote.
Despite differing management techniques, research, and aversion approaches, the end result is often the same — bears come back and are eventually killed. Nevada has a three strikes rule: if the bear is caught three times it gets put down. California issues depredation permits, which gives homeowners permission to kill bears that cause property damage.
In the case of Yogi, Klip says the private property owners have decided to install electric fences to keep the bear away from their yummy-smelling trash compactor. “It’s the only thing that works,” he said.
In this case, Klip achieved a side effect of aversion conditioning. By inviting the property owners to witness the bear’s traumatic experience, he has taught the humans a lesson rather than the bears.
“The use of non-lethal deterrents may have the added benefit of increasing public awareness of human-bear conflicts that are created through the availability of urban food sources in the form of garbage,” Beckman wrote in his 2002 paper, noting that two homeowners associations in South Lake Tahoe spent $100,000 on 350 bear-proof trash containers.
In the case of Yogi, the property owners witnessed a perfect example of the problem. Immediately after he was caged, poked, yelled at, shot with paint balls, chased by dogs, and climbed a tree, he came back down and started sniffing the loose human garbage that was strewn about the ground, seemingly having forgotten his prior experience when faced with irresistible trash.
The message consistently resonates through the body of research and from managers like Chris Healy, Nevada Department of Wildlife spokesman, and Klip. “Garbage is the main attractant,” Klip said. “If you don’t control their access to garbage, the problem will never end.”
New Research and Solutions Recently, Klip, in conjunction with UC Berkley, has been affixing GPS collars to bears, alerting them to what the animals do after they are caught munching on garbage. Preliminary information shows some bears are spending months in both urban and wilderness areas.
“What is definitely expanding is that they are showing up in places where they haven’t been seen for some time,” said Klip.
He says bears caught in Tahoe are showing up in Auburn. Bears are also being found in new areas like Petaluma and Monterey. While the range is expanding, it could also mean the population is expanding too, Klip says.
One possible driver of the expansion, according to Healy, is that bear density is increasing in areas like Incline Village because of unsecured garbage. Where bears once had ranges of 25, 50, or 100 miles, “You have home ranges for garbage bears that are 1 or 2 square miles. That’s not normal. You have to deny them the use of that garbage.” The density may be driving bears out of areas and possibly taking their garbage habits with them.
The Nevada Department of Wildlife has recently called on people to better manage their garbage through local government mandated bear-proof trash containers. The Incline Village General Improvement District Board heeded that call, and on Dec. 10, in a 3-2 vote, approved proceeding with its proposal to mandate bear-proof containers for both residential and commercial properties. A public comment period will open in January on the proposal, with a final board vote in February.
“When you are not managing your garbage properly, it’s those entities [local governments] that aren’t pulling their weight,” Healy said. “Remember, the attractant is what? The garbage. Who manages the garbage? Not the Nevada Department of Wildlife.”
If bear-proof trash containers are mandated, it may be a tough transition for area residents, but even tougher for the bears that eat nothing but garbage.
“Will you end up having bears that will not survive that transition?” Healy asks. “Most likely.”
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