Categories: July 2011PEOPLE

The Bear Truth

Ursa Major: Life-long bear biologist Lynn Rogers is known as the “Jane Goodall of Black Bears.”

Most people think Lynn Rogers is crazy. The 71-year-old wildlife biologist walks with bears. He follows black bears for miles as they search for food through the Northwoods of Minnesota, trudging through marshes, straddling fallen trees, and kayaking across lakes to keep up with them. He studies their behavior and development from extremely close distances over 24-hour periods, sometimes even resting right beside them. Because of the trust these bears have for him, he’s become known as the “Jane Goodall of black bears.”

Rogers, head of Minnesota’s Wildlife Research Institute, has authored dozens of peer-reviewed papers on black bears. Several of his discoveries are owed to his close contact with bears. In over 40 years of research, though, he believes his most important finding is that black bears are not the vicious animals we once thought they were.

Bear Basics

In the Southeastern U.S., the black bear population is growing steadily. That’s why bears are classified as game animals in states like Tennessee, Virginia, and North Carolina.

“A lot of people don’t realize how adaptable this animal is,” says research ecologist Frank van Manen of the U.S. Geological Survey. “This species is a very opportunistic one.”

Over the past 80 years, the situation for black bears has improved, van Manen says. The Southern Appalachians are no longer heavily exploited for timber as they were in the 1930s. In addition, forests in the Southeast are dominated by oak trees, which have been highly productive, he says. That means more acorns for bears.

In Louisiana and Florida, however, the situation is different. Louisiana’s subspecies of black bears is classified as “threatened” by the Endangered Species Act. Although Florida’s subspecies is not listed by the federal government, the state classifies it as “threatened.”

Across the country, the biggest threat facing the planet’s largest mammal is the shrinking and fragmentation of its habitat. As development encroaches on wild spaces, black bears are losing their homes and their natural sources of food. This is causing an increase in bear-human interactions, something that bear management experts work to avoid.

Bear Management

The Great Smoky Mountains National Park is home to about 1,600 black bears, the largest concentration of bears in the Southeast. The park also has an incredibly high concentration of humans: it’s the most visited national park in the country, receiving between 9 million and 10 million visitors each year. These colliding populations make bear management particularly challenging.

“Most of the park is wildlife habitat available for bears. But there are parts that are people habitat: campsites, picnic areas, parking lots,” explains Bill Stiver, a wildlife biologist in the Smokies who has focused on bear management for over 20 years. “If we allow bears to be comfortable around people, sooner or later they’re going to get into garbage. And when that happens, eventually you’re going to have bears climbing on picnic tables and breaking into cars.”

Bears that go searching for trash and human food are “nuisance bears.” A major part of Stiver’s job involves managing nuisance bears, both with preventative and rehabilitative measures.

Instinctively, black bears are afraid of people. “When they encounter a person, they take off running,” Stiver says. “They don’t want anything to do with people.” But if there’s food lying around after people are gone, a bear may investigate. If the problem continues, the bear will show up night after night. As long as there’s still the promise of food, says Stiver, “they’ll get bolder and bolder and show up earlier and earlier.”

The key to preventing nuisance incidents is education, he says. The biologists and park rangers in the Smokies do their best to educate people about proper food storage and proper trash disposal. Signs are posted around campsites alerting campers and hikers that they will incur fines for violating storage rules. But the park still occasionally ends up with dumpsters overflowing with garbage and campgrounds cluttered in food and trash.

Even if we’re 90 percent successful in educating the 10 million visitors to the park, that still leaves one million people who may not be aware. And it just takes a handful of people to start a problem.”

When park officials are alerted to a nuisance bear, they set a trap to catch and tranquilize it. Their goal is to fuel the bear’s fear of people. After weighing, measuring, and then ear-tagging the bear, park biologists will re-release it into the mountains. Usually, Stiver says, this strategy is successful. When a bear keeps returning to the scene of its crime, though, the biologists must resort to removing it from the area. Since bears have acute homing instincts, that means moving the nuisance bear at least 40 air miles away, Stiver says. “We don’t like doing that. But it is an option.”

Occasionally, nuisance bears will be moved into captivity. The Maymont Foundation in Richmond, Va., is home to one of the region’s only exhibits of native bears. One of Maymont’s two male black bears is a former nuisance bear who broke into a house trailer searching for food. Incidents like these occur when bears cannot find natural sources of food, something that is becoming increasingly difficult for them as their habitats shrink.

“Although the bear-human interface is one of the most important areas of bear management,” says Lynn Rogers of the Wildlife Research Institute, “it is perhaps the least studied area, because everybody thinks they already understand it.”

Take, for instance, the conventional wisdom that feeding bears is dangerous both for people and bears. While Rogers concedes that the warning “a fed bear is a dead bear” should be heeded in campgrounds, he and other biologists have found that feeding bears doesn’t always have negative effects. “You can lead a bear into trouble with food, but we’ve also found that food is a powerful tool for leading bears out of trouble,” Rogers insists. In an eight-year diversionary feeding study in Minnesota, Rogers found that putting out food at least one-quarter of a mile away from campgrounds stopped nuisance incidents from occurring.

A similar effort was prompted a few years ago in Lake Tahoe when forest fires and drought caused bears to break into houses in search of food. A local nonprofit called the BEAR League, led by director Ann Bryant (the subject of a new Animal Planet show called Blonde vs. Bear) began illegally putting out food in areas away from the homes. In those areas, bear break-ins dropped from two or three a day to zero. In the other areas, bear break-ins continued at high rates.

Neither of these experiments were published in peer-reviewed journals. Rogers had the support of state government, while Bryant obviously did not. What they do demonstrate, however, is how much more research needs to be done in the area of bear-human interaction.

Working in a national park, Stiver says he and his colleagues would never use supplemental feeding to manage bears. “When a bear comes into a picnic area, it’s associating any food there with human scent,” he says. “Our goal is to keep bears wild and afraid of people.”

Up Close and Personal

Back in Minnesota, Rogers has been following one family of bears over multiple generations. He no longer uses bear traps or tranquilizers, not even when putting radio collars around the bears’ necks. Instead, he uses food, like grapes or nuts, to gain their trust.

Providing them with small amounts of food not only allows him to get close enough to fasten radio collars, install GPS units, or set up video equipment, it also maintains their familiarity with him. Rogers calls to the bears to establish his presence, and they clearly recognize his voice. “I feel very privileged that they will trust me and let me see the secrets of their lives. I know they don’t have any feelings or affection for me, of course. And we don’t want them to, you know. But, at the same time, I feel close to them.”

This lack of detachment is what leaves Rogers open to critics. “When you’re dealing with behavioral research, you want to make sure you don’t change the behavior of the animal,” explains the U.S. Geological Survey’s van Manen. “It would be very difficult to not change the behavior of the animal when you’re right there with the animal or when there’s food involved.”

Rogers argues that this was the same sort of criticism directed at Jane Goodall, the world-renowned primatologist who pioneered the study of chimpanzee behavior. And since black bears are solitary animals that are difficult to track, Rogers believes his hands-on field studies are the best way to record behavior, development, and social interaction.

Rogers’ scariest moments are during hunting season. “It’s a very scary time,” he says. “We try to stay with the bears to protect them.”

It’s hard for them to see hunters, who are dressed head to toe in camouflage, and it’s hard for hunters to see them, through the forest’s thick curtain of leaves. So the researchers are just as likely to be shot as the bears they pursue.

Rogers’s brand of extreme science is seen by some as just plain reckless. But it’s hard to deny that good research has come out of it. Close contact with bears has resulted in the first-ever video footage of a wild bear giving birth. Rogers and his colleagues set up a “den cam,” which also allowed scientists to observe hibernation. They learned that bears wake up during the winter to play or eat snow, contrary to previous assumptions. Rogers’s research center also snagged the first-ever footage of wild bears mating, dispelling beliefs that this is an especially dangerous time to encounter bears.

His research has also revealed certain aspects of bear diets. Rogers has found that bears show a preference for plants like jewelweed, clovers, and wild calla. Close observation was necessary for this determination since highly digestible foods don’t appear in bear droppings the way berries, nuts, or insect larvae do.

His most powerful finding is that bears are not as threatening as television, movies, and hunting magazines would have us believe. “If the stuff I was saying was wrong, I’d be dead by now.

What We Can Learn From Black Bears

1. What we can learn from bear body control Bears can regulate temperatures in variable cycles during hibernation. Bears’ body temperatures fell by 43°F, their heart rates slowed from about 55 beats-per-minute to 14 beats-per-minute, and their metabolism dropped by 75 percent. After waking up, the bears’ metabolism remained at low levels for up to three weeks, indicating the presence of a biochemical mechanism at work. Biologists believe these findings bring us one step closer to determining how hibernation-like states can be induced in humans.

2. What we can learn from bear bones Even after months of inactivity during hibernation, black bears exhibit very little loss in bone and muscle mass, allowing them to become physically active almost immediately. Bears may work their muscles during hibernation by shivering or isometric activity. Understanding these mechanisms could lead to new treatments for osteoporosis and disuse atrophy. NASA also funds bear research to help astronauts fight muscle and bone loss in space.

3. What we can learn from bear breaths When hibernating black bears breathe in, they can increase their heart rate by 800 percent; when humans breathe, they can only increase their heart rate by 20 percent. Scientists believe that mimicking bears’ “respiratory sinus arrhythmia” could benefit humans with poor heart function.

4. What we can learn from bear kidneys During hibernation, bears can go for months without urinating. Unlike in humans, bears’ microbes successfully recycle the waste urea in urine. Humans’ microbes don’t work as effectively, so the inability to recycle urea causes kidney failure. As a result, doctors from Harvard Medical School are conducting further research of bear kidneys.

5. What we can learn from bear biochemistry Hibernation allows bears to take in less oxygen without harming the brain or heart. It’s triggered by opiate-like compounds called deltorphins, which have been found to help mice and rats survive strokes, severe hemorrhaging, and heart attacks. Understanding their possible activity in bears could lead to use of these compounds in human medicines.

Black Bear Myths

Myth: Black bears are mostly carnivorous. Although black bears are omnivores—meaning that they eat both vegetation and animal meat —their diets are on average about 85 percent vegetarian.

Myth: A black bear standing on its hind legs is getting ready to attack. Black bears stand up on their hind legs when they want more information about their surroundings. Standing helps them see farther and take in the sights, smells, and sounds of their environment.

Myth: The most dangerous time to approach bears is when a mother is with her cub. Although grizzly bears can attack when a human comes between mother and cub, black bears are likely to, at most, bluff charge and vocalize. According to bear biologists, black bears are too afraid of people to attack defensively.

Myth: All black bears hibernate all winter long. In areas with warm weather and plentiful food during the winter, black bears may not hibernate at all, or may only do so for short periods of time.

Myth: Carrying a gun is the most effective way to guard against a bear attack. The U.S. Fish and Wildlife Service recommends using pepper spray as opposed to firearms to protect against a bear attack. The government bureau found that shooting a bear can escalate an attack. “Experienced hunters are surprised to find that despite the use of firearms against a charging bear, they were attacked and badly hurt,” the Fish and Wildlife Service reported in a fact sheet. On the other hand, people defending themselves with pepper spray have escaped injury the vast majority of the time.

Myth: Bear attacks are common. Only 15 people have been killed by black bears in the past decade. You’re 40 times more likely to be struck by lightning than attacked by a bear.

When Black Bears Do Attack

One thing black bear experts can agree on is how rare attacks are. You are far more likely to be killed by a dog or an earthquake than you are by a bear.

But that doesn’t mean you should act carelessly around bears. Buz Bireline, who works with bears at the Maymont Foundation in Virginia, was hiking through Cades Cove in the Great Smoky Mountains. “I saw people running after a bear to try and get its picture,” he recalls. “I believe we have an innate drive to connect with the wild. But it can lead us to make bad choices.”

When black bears exhibit aggression, their behavior is either defensive or offensive. A defensive bear says “you are too close” by swatting the ground, bluff charging, blowing, and vocalizing. A female with her cubs may act this way. Back up slowly, without making direct eye contact, and the bear will likely do the same.

An offensive bear exhibits predatory behavior by keeping its head down, following you, and not vocalizing. If this happens, stand your ground. Shout loudly, act aggressively, and try to make yourself appear larger than you are. If you’re with other people, group together and try to move to higher ground. Throw rocks and anything else you can find.

Carrying pepper spray is the best way to protect against a worst-case scenario. Dog-deterrent brands like Halt shoot straight streams, whereas bear-deterrent brands like Counter Assault shoot fogs which, while more powerful, can get in your eyes.

 

Published by
Suemedha Sood