Rangers vs Yogi the Bear

Rangers get tough on picnic-stealing bears

It may sound more like riot control than wildlife management, but at last there is now a scientifically backed method for dealing with “nuisance bears”.

Firing rubber bullets, backed up by chasing and yelling, can deter the animals from entering picnic sites and campgrounds in search of human food, say biologists with the US National Park Service.

Black bears (Ursus americanus) overcome their natural fear of people if they smell food, and have little trouble popping a car’s window or ripping off a door if they see a picnic hamper, backpack or drinks can.

“They’re very clever and they learn very quickly,” says Rachel Mazur, a biologist with the Sequoia and Kings Canyon National Parks in California.
Bear-proof chests

Visitors to national parks in the US are told to store their food in bear-proof metal chests, available at campsites, picnic areas and trailheads. Even so, it is difficult to keep people and bears apart.

And once a bear starts hanging around where people congregate, it usually has to be shot, or relocated to an unfamiliar area – which in most cases is also a death sentence.

Bears that are habituated to people also tend to get hit by cars. Sadly, the slogan “a fed bear is a dead bear” is all too true.

Early attempts to deter bears by adding foul-tasting chemicals to food baits, or rigging cars or picnic tables to deliver electric shocks, met with failure. Bears are too intent on filling their stomachs to care much about a nasty taste, says Mazur, and they soon learn to distinguish a picnic table that has been electrified from one that is not.
Aggressive tactics

So since 2002, rangers at Sequoia and Kings Canyon have been trying more aggressive tactics, responding to bears that encroach onto campgrounds and picnic sites by throwing rocks, firing rubber bullets, chasing the animals and yelling.

Mazur revealed the results for 36 different bears at the Society for Conservation Biology’s meeting in San Jose, California this week. For those that were already known as nuisance bears, only the rubber bullets had any real effect.

And six of the 11 bears that had to be driven off more than 24 times proved recalcitrant and had to be shot or relocated.

But for bears with little previous experience with human food, the deterrent worked remarkably well. After a few encounters with aggressive rangers, most subsequently kept away from people.

This is the first evidence that nuisance behaviour can be changed in its early stages – which tend to occur around picnic sites, rather than the more densely populated camping sites.

“I was really surprised at how well it was working,” Mazur admits. So the programme is now being expanded, with more park staff being trained in the strong-arm tactics.