When Kerry Gunther takes on a backpack, he likes to visit the desert Southwest.
There are two reasons why the lead bear biologist in Yellowstone National Park mentions for his penchant for traveling south. One is that he has more time off in the winter, where bears go to sleep, and the weather in the southwest in the winter is quite mild and free of tourists. The other reason is that he does not have to worry about grizzly bears when pitching his tent.
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“You do not have to keep that in mind,” he said.
The rest of the year, when bears roam the countryside, black bears and grizzlies are always at the forefront of Gunther, who has spent 39 of his 62 years working with brownies in the country’s first national park.
“There are so many ways they can come into conflict with people, usually because of people’s guilt, and we’re called to deal with them,” Gunther said.
Thanks to the protection from the creation of Yellowstone National Park, Gunther works in one of the few places where grizzly bears have survived the onslaught of Euro-American settlements in the lower 48 states. While the great browns were hunted and captured for extinction elsewhere, grizzlies were able to hide in the more than 28,000 square miles of the Greater Yellowstone Ecosystem.
Even with that protection, the number of grizzly bears in the GYE dropped to an estimated low of only 136 animals in the mid-1970s, although it is difficult to verify this figure for a species occupying remote terrain. Due to the low bear populations, the species was protected by the US Fish and Wildlife Service in 1975 under the Endangered Species Act.
Dan Wenk noted in the book “Yellowstone Grizzly Bears: Ecology and Conservation of an Icon of Wildness” that grizzlies were rare when he first worked in the park from 1979 to 1984. He saw only five throughout that period. When Wenk returned to Yellowstone in 2011 as superintendent, he noticed a clear shift. In one day on a drive through the park, he counted 10 grizzlies.
“It was quite clear that this was a different park than the one I left more than 25 years earlier,” he wrote.
Thanks to recovery efforts, GYE’s grizzly bear population is now estimated by wildlife officials to be 690 bears with one star. Bear populations can be underestimated by 40% to 50%, the agency’s scientists claim.
“We probably reached ecological sustainability in the mid to late ’90s,” Gunther said. “The population is now quite stable.”
These numbers have been challenged by grizzly advocates outside of federal and state agencies. Environmental groups have repeatedly and successfully fought to keep grizzlies on the list of endangered species due to the many threats to traditional food sources. These include a loss of 70% of white bark pines whose seeds are high in protein, and dramatic declines in Yellowstone brown trout and elk populations inside Yellowstone.
Bears have also coped with the 1988 fires in Yellowstone, which burned more than 800,000 acres, and the reintroduction of wolves, which started in 1995.
Despite the loss of traditional foods, grizzly biologists note that Yellowstone’s bear population has grown due to the animal’s ability to adapt and its omnivorous nature. By collecting and analyzing scat, researchers identified more than 260 items on the grizzly bear’s menu, led by 20 to 30 most consumed. What’s more, researchers through capture studies noted that despite the decline in some food sources, grizzly bears have maintained a healthy body condition.
“They can survive almost anything as long as we do not kill them,” Gunther said.
But loss of food sources could lead to bears seeking new home areas outside of Yellowstone, as competition for food could push out less dominant bears as males seek out places to avoid confrontation, Gunther noted.
“They wander as far as they need to eat,” he said.
Migratory bears are the main cause of people management, Gunther noted. By protecting waste containers, homes and campsites, these bears do not receive food rewards that could cause them to associate humans with a meal.
“What’s lucky for us is that almost all (human) visits take place in developed areas,” Gunther said.
So the hinterland, where bears want to be, is mostly free of human intervention. Visitor surveys have shown that the majority of the park’s 4 million annual visitors do not get more than two to three miles away from the boardwalks. Although there are 300 designated backcountry campsites, they are rarely filled every night.
“So bears still have millions of acres with little human use,” he said. “In the best habitat in the park, the use can only be so high,” as the use of backcountry is controlled by a permit system.
Researchers continue to expand their knowledge of Yellowstone grizzlies, including a recent study examining a decade of data from GPS collar bears showing how they exploit the landscape of Bear Management Areas, which are temporarily closed or restricted to human access to avoid conflicts.
BMAs were created in 1983 to reduce bear-human encounters in designated areas, such as around Old Faithful in the spring. Bears will seek out winter killers, often bison bodies, to feed after waking from hibernation. The BMAs were created based on recommendations from park staff. The new study, expected to be completed next spring, will point to what habitats bears use.
“Anything that restricts recreational use is controversial, so this will be useful,” Gunther said.
At these backcountry campsites, Park Service has made it easier for campers to store their food safely by installing metal “bear boxes” or rods to hang food out of a bear’s reach.
“If you make food storage easy and convenient, people will use it,” he said. “We try to make it easier for people to do the right thing, which keeps bears out of trouble.”
The effort has been largely successful with few human-bear conflicts despite increasing visits. Yellowstone visitors have a 1 in 63.4 million chance of being injured by a grizzly bear, which drops to 1 in 1.7 million for those camping inside the park.
During his tenure in Yellowstone, Gunther has seen the visit double from about 2 million people a year to 4 million.
“The ecosystem used to be very remote and rural, and now a lot of people live in the ecosystem,” he said. “So the human-bear interface becomes more of a challenge.”
Some of these people are building homes in what is now referred to as the Wild Urban Interface, or WUI, next to national forests and trout streams, which are seen as facilities that increase the value of a property. Such a development means fewer places where wildlife can avoid contact with humans.
In the Greater Yellowstone Ecosystem, which extends beyond the park, more people visiting to hunt and hike have also increased the number of encounters between humans and bears. The leading cause of grizzly bear mortality in GYE is from hunters who shoot bears in the fall when brownies actively seek food before going to sleep. Some moose hunters joke that a rifle shot in the fall is like ringing a dinner bell for a grizzly.
“Currently, the highest proportion (30%) of all reported grizzly bear deaths is associated with shots fired by ungulate hunters (mostly self-defense killings), followed by conflicts with humans in developed areas (25%) and extinction of livestock (19%), “according to the book” Yellowstone Grizzly Bears. “
The key to reducing these bear deaths is better education. Many hunters and hikers do not carry bear spray, a proven bear deterrent when deployed. Even in Yellowstone, fewer than 30% of visitors carried bear spray, a park survey showed.
Finding a way to reduce bear-human conflicts will help build more social tolerance for the large animals in the landscape, Gunther said. The hard part is that there are always some people who are unaware of how to recreate in the grizzly bear country.
“They just don’t behave very well,” he said.
He cited three cases this summer in which campers in the backcountry freaked out after seeing bears and leaving all their food and equipment.
“It could have been bad for the bear and for the next people to camp there,” he said. “Just because you see a bear, it will not kill you.”
Gunther said Yellowstone probably reached its ecological carrying capacity for grizzly bears in the mid to late 1990s. Since 2001, scientists have recorded slow growth, in part due to lower survival of young people and one-year-olds – two ages that are difficult for scientists to monitor.
Despite a relatively small population when the animals were listed as endangered, studies have shown that Yellowstone grizzlies have retained genetic diversity. However, one of the goals of bear managers is to increase the genetic diversity of animals to help them meet future challenges that climate change may pose. To do so without human intervention, grizzlies from the Northern Continental Divide ecosystem must migrate as far south as Yellowstone or vice versa. So far it has not happened, but Gunther remains optimistic that it may happen one day soon. If not, bear managers have the ability to capture and release animals from each ecosystem to manually attempt to increase genetic flow.
One of the major complications is that a bear can successfully navigate the landscape between Glacier and Yellowstone National Parks requiring crossing highways, rivers and human development without running into conflict.
“Right now, our genetic diversity is not in jeopardy, but in the end, if they do not connect, it could be,” Gunther said. “In the next decade or two, that could happen.”
Suggestions from park critics that bears are leaving Yellowstone due to critical food shortages are unfounded, he said. Instead, the rising bear population is what motivates some animals to leave the protection of Yellowstone.
“Our numbers are pretty stable,” Gunther said. “Handheld bears have not moved.”