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PRI's Environmental News Magazine

How to Scare a Bear

Air Date: Week of February 5, 2010

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What’s the most effective way to scare a black bear? Bear technicians in California have been trying a variety of techniques on "nuisance bears" to determine how to keep them from raiding picnic areas and campgrounds. Host Jeff Young spoke with biologist Rachel Mazur, author of a recent study about how to reduce unwanted human-bear interactions.


YOUNG: The giant trees of Sequoia National Park in California attract nearly a million visitors each year. All those people and their picnic baskets also attract a lot of black bears. Last year alone, the park reported over a hundred human-bear conflicts. So park officials wanted to know how to reduce those risky wildlife encounters.

Bear biologist Rachel Mazur has been working on the problem – and published a study on how best to scare a bear.

MAZUR: Basically, I've been working at the Sequoia and Kings Canyon National Parks where we have massive numbers of human-black bear conflicts, as they do in many other parts of the country and other parts of the world, and we're looking for solutions and using hazing, or aversive conditioning, on these bears was something we'd been doing but we didn't know how well it was working.

YOUNG: Aversive conditioning – what are we talking about here? Trying to scare them?

MAZUR: Yes, in a way. I mean, basically what you’re doing is trying to retrain behavior. And so you’re trying to make them associate something negative with what they thought was something positive. So, where they would go into a campground or go into a car or something to receive human food, we want them to think of that as something they don’t want to do.

YOUNG: So what kind of things are you doing here – what are we talking about actually?

MAZUR: The most common one is really just yelling at bears: get out of here bear! Waving your arms, looking big.

YOUNG: [LAUGHS] And how does that work?

MAZUR: [LAUGHS] It works pretty well on naïve bears, or – we call them naïve bears, but bears that aren’t very food-conditioned, used to human food, or very habituated. But then there’s other methods that are much more intense using pepper spray, using paintball guns, using rubber slugs, which are basically the rubber bullets you think go with riot teams or something like that.

YOUNG: And how do those techniques work?

MAZUR: They’re mixed. So on the naïve bears, they work great; they work great in saying, don’t come into these areas, this is not a good place for you, you want to go back and eat acorns and eat berries and that sort of thing. With bears that have already received a lot of human food and are used to entering human areas, they’re not very successful.

They will, however, keep bears away from humans, increase their fear of humans, and make them change their techniques for getting human food. So, instead of coming in boldly in the middle of the day and walking up to a picnic table, they might sneak in at night and grab a cooler that’s hidden behind a tree.


YOUNG: So at least you’re reducing the chance of something really bad happening, but they’re still going to raid the trash can occasionally, that sort of thing, but –

MAZUR: Exactly. In terms of, you know, re-wilding them or however you want to phrase it, the success rate’s pretty low.

YOUNG: You know, I find this very interesting in part because a couple summers ago I had a bear encounter of my own, and I tried to scare that bear, or so I thought. And I got to tell you, the bear was not impressed, and he did what I think you call a bluff charge, and –

MAZUR: Okay.

YOUNG: I ran away, I may have screamed like a little girl, but lets just say I did not succeed in scaring the bear. What did I do wrong, and what should I have done in that situation?

MAZUR: [LAUGHS] Well, first of all, you never run from a bear because –

YOUNG: There’s strike one against me: I should not have run screaming like a little girl – probably not good, either. [LAUGHS]

MAZUR: As a side note, the gender and size have nothing to do with it, but what people do a lot is a bear will come into their campground, and they’ll say, “Get out of here bear!” And they get all excited and go running after the bear and they leave their food on the picnic table, so we say it’s great to yell, it’s great to try to make them afraid of you, but put your food away! That’s the most important thing.

YOUNG: Well, you know, it sounds to me like what you’re really after is not so much changing bear behavior, but changing people behavior.

MAZUR: Exactly. It’s way easier to just put your food away to begin with than creating this problem and trying to fix it. And so, if you’re in one of these parks where you have a million visitors in a place like Yosemite, several million visitors coming in a year; you have a lot of people to train.

Sometimes when you talk to people, everyone has a story of a bear getting their food. So, if you imagine a million people all letting a bear get at their food once. You’ve got a problem. And so there’s constant education of people: holding your food, how to be around bears, giving them space. We don’t want people near bears; they should be 50 meters away from bears. People like to say, “Oh I could get really close and get a good photograph.” Well, instead get a telephoto lens. Stay away from them. What you’re doing, the closer you’re getting to them is you’re habituating them or muting their response to humans.

YOUNG: I guess that’s something that a lot of visitors to parks need to keep in mind is it may seem harmless to throw a marshmallow to a bear, and oh isn’t it cute? But, in the long-term you may doom that animal because if it becomes a regular there park managers may have no choice but to kill the animal, right?

MAZUR: That’s true, and I think a lot of times the people who first gave food to the bear are long gone by the time the bear’s behavior is so, I guess you’d say, risky that you need to take its life. And so near the end of a bear’s life, the people that have left their food out, they might have just left out a candy wrapper or something small. And so they feel horribly guilty, but it was really the person three months earlier that had left a cooler unattended while they went to the bathroom that really caused the problem.

YOUNG: Did you ever feel like the ranger in a Yogi Bear cartoon during all this?


MAZUR: [LAUGHS] You often feel, yeah, they would sneak, you’d be looking for them, we’d spotlight around – where are the bears, looking around. And they’d be hiding behind the dumpster, but their butt would be sticking out one end, so you could see –



YOUNG: Bear biologist Rachel Mazur telling us about the best ways to scare bears. Thanks very much.

MAZUR: Thank you.



Check out Rachel Mazur’s book, “If You Were a Bear”


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