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Research highlights predatory black bear behaviour

A predatory male black bear is far more dangerous and likely to kill people than a mother black bear protecting her cubs.

A predatory male black bear is far more dangerous and likely to kill people than a mother black bear protecting her cubs.

That’s according to the latest research by renowned bear expert Stephen Herrero, which was published on May 11 in the Journal of Wildlife Management.

His black bear research concludes females with young are not the greatest threat; instead, lone males hunting people as a potential source of food are a greater cause of deadly maulings.

The study also shows attack rates are rising with human population growth and expansion into the bear’s wilderness home ranges. Also of note is no one who was killed by a black bear was carrying bear spray.

“Fatal attacks by black bears are a rare occurrence, and the fact is there hasn’t been one in Alberta for more than 10 years, but they do happen,” said Herrero, professor emeritus at the University of Calgary.

“This is pretty strong evidence that predacious male bears are more dangerous. It fits with the nature of males and the competition they have with each other and their willingness to take risks.”

Herrero and U of C graduate Andrew Higgins analyzed the circumstances of all recorded deaths by non-captive black bears in North America between 1900 and 2009.

The study found that 63 people were killed in 59 separate incidents in Canada, Alaska and the lower 48 states.

Most fatal attacks by black bears have been judged as predatory. The researchers determined that the bear involved acted as a predator in 49 of the 56 (88 per cent) fatal incidents.

Adult or sub-adult male bears were involved in 33 of 36 (92 per cent) of fatal predatory incidents, reflecting biological and behavioual differences between male and female bears.

“That most fatal black bear attacks were predatory and were carried out by one bear shows that females with young are not the most dangerous black bears,” said Herrero.

“Females select habitat and behave to support security. On the other hand, male black bears typically have larger home ranges, exposing these bears to more risks because of more potential for interactions with people.”

While this study documents the circumstances of all recorded fatalities, there are also many instances involving serious maulings that don’t end in the death of a person.

In 2006, Town of Banff employee Greg Flaaten narrowly escaped with his life when a 125-pound black bear attacked him as he was riding on a remote Tunnel Mountain trail near Banff.

The bear was subsequently shot and killed.

Banff town manager Robert Earl and Robin Borstmayer came across Flaaten’s abandoned bike and broken helmet on the trail that May 12 evening – and knew their friend was in trouble.

Flaaten, who had been dragged more than 50 metres from the initial point of contact by the bear, suffered extensive injuries, and was destined for much worse if the riders had not come across the scene.

“I’m just so thankful that we were there last night,” said Earl at the time.

The authors of the paper also worked with colleagues from the Massachusetts Division of Fisheries and Wildlife and Brigham Young University.

They found that bears that have previously killed people are more likely to attack again and that parties of more than two people are less likely to be attacked.

As well, this study reconfirmed that human food and garbage tends to attract black bears and may increase the likelihood of serious bear attacks.

The researchers also uncovered that there were 3.5 times as many fatal attacks in Canada and Alaska, but only 1.75 times as many black bears, and much less contrast for black bears in Canada and Alaska.

Human population growth is accompanied by rising fatal bear attacks.

“We didn’t demonstrate why population growth correlated with more black bear attacks, but we suspect it is because there are more people pursuing recreational and commercial activities in black bear habitat,” said Herrero.

“Similarly, we don’t know exactly why there have been more attacks in Canada and Alaska, but we speculate it could be because bears in those areas are living in less productive habitat with periodic food stress, which may predispose some bears to consider people as prey.”

Herrero said one of the key questions that arises is why black bears don’t attack people more often, noting a 100-pound black bear is a “pretty good match” for a 200-pound human.

“The ones that have tried it have come up with a much more aggressive species – homo sapiens,” he said. “Any bears that have this tendency have been eliminated from the population.”

As a result of the research, Herrero said agencies managing black bears can more accurately understand the risk of being killed by a black bear and can communicate this to the public.

“With training, people can learn to recognize the behaviours of a bear considering them as prey and can act to deter predation,” he said.

Parks Canada officials say Herrero’s paper further reinforces the information the agency has been giving the public, which can be found on the website at

There have been several sightings of bears in Banff so far this spring, including a female black bear with four cubs spotted last week in the Lake Minnewanka region.

Parks says the best thing to do is avoid a bear encounter in the first place – make noise, watch for fresh bear sign, keep dogs on leash, travel in groups and always carry bear spray.

If an encounter takes place, stay calm, get bear spray ready, talk calmly and firmly, back away slowly, and make sure to leave the bear an escape route.

If a bear attacks, people may increase their chance by evaluating whether the bear’s behaviour is defensive or predatory.

“If you get into that exceedingly rare situation and are actually contacted, our recommendation is to do anything you can to fight back,” said Steve Michel, human-wildlife conflict specialist for Banff National Park.

Michel said it is important to note that the 100-plus years of data compiled by Herrero and his colleagues clearly indicates predatory attacks are extremely rare.

“Having said that, that doesn’t mean an incident like that wouldn’t happen here in the Bow Valley tomorrow,” he said.

“It can happen anywhere, anytime, and people need to be prepared and know how to respond accordingly.”

Michel also wanted to stress that Herrero’s report focuses only on black bears – not grizzlies.

“There is a vast difference between the two species and how they respond to people, particularly in a surprise encounter,” he said.

“If you surprise a female grizzly bear with cubs, you should expect her to exhibit defensive behaviour and that might be much more aggressive than if you encountered a female black bear with cubs.”

Parks Canada asks all bear activity be reported to 403-762-1470.

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