Pepper spray, rocks or rubber slugs are good tools for scaring bears from park picnic areas. But the best way to get rid of black bears is to not invite them over to begin with.
Trying out various techniques on bears in Sequoia and Kings Canyon National Parks in California, wildlife managers report some success in using obnoxious maneuvers, such as deploying sling shots and throwing rocks, to keep black bears from seeking people, food and garbage. But the approach was less successful with bears that already had a taste for the forbidden foodstuff, the study published in the January Journal of Wildlife Management shows.
Establishing which techniques and circumstances will thwart food-seeking bears is valuable, but such techniques should be tried only after making trash and food inaccessible, says Rachel Mazur, who led the study while she was a wildlife biologist at the Kings Canyon park. Bear-proof containers should be available and the public needs to be educated on using them, she says.
Thanks to conservation efforts, better management and shifts in hunting activities, the number of black bears has climbed in the last hundred years, says ecologist Jon Beckmann with the Wildlife Conservation Society. So has the number of people, especially in the public lands of the American West. This means more bear-human interactions.
Like parents experimenting with spanking versus time-out, Mazur and her team spent three years methodically trying "aversive conditioning" techniques on black bears. Aversive conditioning associates a negative stimulus with unwanted behavior, in this case coming near humans, human food or human developments. Negative stimulants included chasing, pepper spray and lofting projectiles of different intensity: rocks, slingshots and rubber slugs.
The team tried the conditioning techniques a total of 1,050 times on more than 150 bears. (While being as methodical as possible, concerns about the safety of park visitors dictated using chasing and rock-throwing more than the other methods). Of all the interactions, 729 involved 36 bears identifiable to the researchers as food-conditioned; that is, animals that had already bitten the apple and were after more. The remaining 321 interactions were with bears naïve to delicacies of human food and garbage.
During the study, bears were hazed from campgrounds, roadsides, picnic areas, natural areas and employee housing. Chasing and rubber slugs worked best to scare off wild bears, and bears experiencing these treatments along with pepper spray stayed away the longest. Rubber slugs worked best to get food-conditioned bears out of an area.
Such approaches can be useful to keep a bear away until food or garbage can be put away, or to get a female to stash her cubs in a tree instead of bringing the youngsters to the picnic, says Mazur. But Mazur would rather not have to use these techniques at all. "This isn't what we want," she says. "Our goal is to keep wildlife wild."
Beckmann concurs that aversive conditioning techniques can work, but "these are Band-Aid approaches," he says. "It is much better to stop these conflicts before they occur."
Once a bear has a taste for people food, they can be extremely persistent, says Mazur. Eleven of the 36 food-conditioned bears were involved in 90 percent of the hazing events, the researchers found. Only one of these 11 bears completely stopped entering developed areas; four changed their behavior but still had to be hazed every year. The remaining six were so persistent and potentially dangerous that they were killed or relocated.
One of these six bears was a cub. He didn't learn to love human food from his mother, who was food-conditioned herself but gave it up while raising her kid. But the cub was frequently near park visitors who approached and fed the animal.
"The real issue is food availability," says Beckmann. It is very difficult to get 100 percent enforcement on the human end of this interaction, he notes. It may take only one home where a grill is left outside or garbage left exposed, or one energy bar in a camper's pack, to tempt a bear, he says.
The study should inform wildlife managers, but anyone who comes across a bear should make their presence known and then get out, says Beckmann. "You can say something like, 'Hi bear,' and then back away slowly while maintaining eye contact."
Image: National Parks Service
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