Grizzlies Are Increasing in Numbers. Learning to Live With Them.

Aries, an Anatolian shepherd, warily watches a stranger approach a pen where he and other members of his family — including eight fuzzy, 2-month-old puppies — roam alongside a grunting pig and several bleating goats.

Livestock guard dogs like Aries are in demand in Montana these days, an important tool as the state deals with an increasing number of grizzly bears.

Anatolians — large, muscular dogs that originated in Turkey and were bred by shepherds — are extremely loyal and highly protective of those in their care, even against top predators.

“We have gray wolves, grizzly and black bears here,” said Natalie Thurman, owner of Apex Anatolians, whose pups go for $3,300 each. “We just had a grizzly bear in the creek a hundred yards from here.”

While she markets the dogs primarily to people who raise livestock, she also sells them to people with children. “They take them on hikes, they take them camping,” Ms. Thurman said. “They tell you when a bear is coming. I can replace livestock, but you can’t replace a human child.”

Grizzly bears are a daily concern for residents in the northern Rockies. The bears no longer live only in the remote high country, in parks, wilderness and surrounding areas. Instead, they have increasingly moved into the valleys and prairies to reclaim portions of their old realm.

They wander onto golf courses, break into homes, stalk chicken coops and raid cornfields. Montana is home to 2,100 grizzlies, by far the most in the lower 48 states, with much smaller populations mainly in Idaho and Wyoming.

Grizzly bear attacks frequently make headlines in this part of the country. Amie Adamson, a 47-year-old Kansas resident, was killed by a grizzly in July as she jogged near Yellowstone National Park. That bear and its cub were captured and euthanized later in the summer after they broke into a cabin and stole dog food. Last year, Craig Clouatre, 40, of Montana, was killed by a grizzly as he searched for antlers shed by elk near Yellowstone.

Sales of bear spray, which contains capsaicin, the chemical that gives peppers their spicy heat, are booming. Many hikers, picnickers, ranchers and hunters — just about anyone who spends time outdoors in bear habitats — pack bear spray these days.

Fall is when the possibility of conflicts peaks. Bears become especially ravenous — a period called hyperphagia — when they are driven to eat far more than they do the rest of the year, to bulk up fat reserves to live on during several months of hibernation.

While black bears, which are also found in the region, attack people, grizzly bears pose a different order of threat — they are generally bigger and more defensive, especially when surprised or when their cubs seem threatened A black bear will usually scramble off, but a grizzly will more often stand its ground.

The grizzly has been listed as a threatened species under the Endangered Species Act in the northern Rockies since 1975, when its population in Yellowstone and Glacier totaled several hundred bears. They have come back in the last half century, with about 1,000 bears in each park and their surrounding ecosystems, and more outside those core areas.

Biologists, conservationists and others hope that as the grizzly population expands, the areas between the five island ecosystems with a good bear habitat in the northern tier of the United States — Yellowstone and Glacier, the Cabinet-Yaak Valley, the Selkirk Mountains in Idaho and the North Cascades in Washington — will become bear-friendly. That would allow grizzlies

to move between them, assuring a healthy flow of genetic diversity to help bears adapt to climate and other changes, and ensure their future.

Much of the territory they once inhabited, however, is crisscrossed with roads and crowded with people who are plopping down homes. Subdivisions, towns, cities, cattle and sheep are spread across the bears’ terrain, and an increase in recreation on public lands brings large numbers of people onto their turf.

And so a grand experiment is underway to manage the human world in such a way that an apex predator and people in a large urban and suburban complex surrounded by large swaths of public land, can coexist with few conflicts.

The future of the bear is at stake, experts say. Although there is a lot of support for bears in the region, attacks on livestock and people can undermine it.

There is plenty of anti-grizzly sentiment as well. The state of Montana has petitioned the federal government to have the bear stripped of its protected status so that ranchers can shoot them if their livestock are threatened. Others would like to see the bear hunted.

The growing number of attacks has also prompted the U.S. Agriculture Department’s Wildlife Services, which has long existed to kill nuisance wildlife, to research nonlethal methods of managing the bears, including remotely activated sound devices, flashing ear tags and drones with thermal imaging that watch livestock night and day, and harass approaching predators.

Of course, confrontations with grizzlies and other bears occur in many other parts of the world where people and bears are moving into each other’s turf. This spring, a jogger was killed as he ran near Trento, Italy, in the Alps, where a population of Marsican brown bears are being restored. China, Japan and other Asian countries have reported similar conflicts and attacks.

Western Montana has adopted a preventive approach called Bear Smart, a concept that began in British Columbia. It focuses on identifying and eliminating things that hungry bears are attracted to — garbage, compost, bee hives and fruit and vegetable gardens.

Russell Talmo, a specialist in conflict prevention and a member of the conservation nonprofit Defenders of Wildlife, helps landowners in Montana, Wyoming, Idaho and Washington apply for cost-sharing grants to install electric fences around their chicken coops, beehives and garbage facilities.

“A fed bear is a dead bear,” he said. “Once a bear gets a taste of the good life, they can be ruined for life.”

At the Clark Fork School, on the edge of Missoula, Mr. Talmo pointed to a newly installed electric fence.

“It’s smack in the heart of the Rattlesnake Valley, which is chock-full of black bears,” he said, as preschool children played nearby. Mr. Talmo’s interest is more than professional — his 2-year-old son, Luther, attends the school.

Officials installed an electric fence around the school’s chicken coop and vegetable garden with a timer that turns it on in the evening.

Mr. Talmo spends a lot of time talking to people about ways to deter bears from getting too close. Some are simple measures, like putting away bird seed or locking up dog food. People also should keep their doors securely closed, which usually — but not always — prevents bears from getting in. “Breaking-and-entering bears are a real thing,” he said.

Once dotted with orchards, the Missoula Valley is still home to plenty of fruit trees that bears frequent, especially in several large drainage areas that funnel bears to the valley bottom where they eat fallen apples.

Fruit-growers in the region are urged to pick their apples quickly. The Great Bear Foundation, a conservation nonprofit, has a program that connects people with volunteers who will help with the harvest. The apples are then donated to local food banks, as well as to a cidery that brews a cider named for the foundation.

“If everyone secures their food, they may pass through town, but they will not stay,” said Elissa Chott, who runs the program.

“Grizzly bears are good at avoiding people,” said Christopher Servheen, a biologist who led the U.S. Fish and Wildlife Service effort to restore the grizzly bear population in the lower 48 states from 1981 to 2016. He now works as a consultant on bear issues.

“The only ones that are alive are good at avoiding people,” Dr. Servheen said. “Bears have a culture, and one generation passes down behavior to the next. So they raise cubs that avoid people.” But if they learn that easy meals can be found in a dumpster, they can pass that knowledge on as well.

Though black bears are the big problem now in the Missoula Valley, their presence represents a kind of dress rehearsal for the grizzlies that occupy territory all around the city.

“They have Missoula hemmed in and are making forays around the edges,” Mr. Talmo said. “By addressing the black bear problem, you are getting ahead of the grizzly bears that are coming.”

Mr. Talmo visited a homestead recently where a grizzly was spotted along Kendall Creek, just east of Missoula, very near to a chicken coop owned by Kathy Ream. Even though her modest home is very close to the bears’ travel corridor, she said she was not worried about having a grizzly in her backyard. “No, I love it,” Ms. Ream said. “I’m really happy about it. It means we’re wilding a little bit.”

Even with the focus on eliminating certain elements that attract bears, they still get into trouble. Jamie Jonkel, a bear management specialist with the Montana Fish, Wildlife & Parks department in Missoula, gets summoned to deal with all sorts of situations. A new bear-resistant garbage can or electric fencing may solve a problem, but bears may have to be trapped and moved.

Aversive conditioning is also deployed to retrain bears that no longer fear people. Mr. Jonkel and his colleagues fire bean bags and rubber bullets at bears in hopes of restoring healthy levels of fear.

“If we get a bear lost in town, confused, comes in for chokecherries, but gets lost in humanity, we will trap or dart and relocate,” Mr. Jonkel said. “But for a bear getting into garbage, breaking into houses, chasing livestock, that’s when it goes management. Most of the time we trap and relocate, or trap and aversive condition.” A last resort is euthanasia.

Beyond cities and towns, rural regions are also changing tactics. The Blackfoot Valley near Missoula has pioneered efforts to keep bears and people apart. Dead livestock, once left on the land, are carted off to a compost facility. Dozens of ranchers have electric fences around their home and ranch facilities. Range riders on horseback mind the sheep and cattle.

The specially bred guard dogs live with the livestock. Some are deployed in layering system of different breeds — “sticky” breeds stay close to the flock or herd while other breeds patrol the perimeter. Some owners put sharply spiked collars on their dogs’ necks that would injure a bear or wolf that bites the dogs.

Hannah Ollenburger, a researcher in Sheridan, Mont., who studies the role of livestock guard dogs in predator management and is the author of “The Atlas of Conflict Reduction,” called it operant conditioning.

“You are shaping the behavior of native wildlife,” she said. If the resistance is too fierce, the bears go elsewhere.

No one knows just how far the grizzly bear, protected as a threatened species, might journey from a bear-proof world. Could they roam their old haunts as far away as California and Colorado?

“Maybe,” Mr. Jonkel said. “The wolf did.”