Crop damage in Forest County, the skin disease mange in Lycoming and Potter and nuisance complaints in Warren. In residential Westmoreland County there were “multiple reports of bears in each township throughout the summer months,” said Matt Lucas, Pennsylvania Game Commission wildlife conservation officer for the region. In recent years, bears have taken up residence in Allegheny County.

Nevertheless, the state wildlife agency does not consider black bears to be a problem. In fact, the shy animal’s proliferation in 55 of 67 counties is viewed as a significant achievement. Managing the animals, and the human conflicts that go with their proliferation, are just routine parts of doing business with bears.

“Every day in Pennsylvania there’s a bear in somebody’s yard,” said Mark Ternent, a biologist and bear specialist with the state Game Commission. “But it’s just not that big of a deal.”

Not long ago, bears were mostly isolated in remote regions of the Appalachian Mountains. Science-based wildlife management has resulted in more than 18,000 bears now sharing the state with some 12 million human residents.

Physical conflicts are rare and minimal. Once or twice a year someone is scratched in a brief bear incident, but no one has been killed by a bear in Pennsylvania since documentation began in 1900.

December will mark the end of a 10-year Game Commission plan that successfully stabilized the black bear population at current levels.

“Today bears are more abundant than at any other time since European settlement, and about four times more abundant than 25 years ago when the trend began,” wrote Mr. Ternent, in the plan he authored. In it, licensed and regulated hunting is used to control the population.

“From 1981 to 2000, the bear population went from 4,000 to 15,000, and that occurred while we were removing about 20 percent of the bears per year through hunting,” he said. “Natural mortality isn’t adequate to stabilize the bear population at the level we’d like to have.”

About 2 to 4 percent of bears are killed annually in vehicle collisions, and a small number die from disease or injury. About 23 percent of the male bear population and 16 percent of the females are removed annually through legal hunting.

The five-day statewide firearm bear season ended Nov. 25. Wildlife officials at mandatory bear check stations were still counting and recording data, but the harvest trajectory was skewing higher than last year’s total of 3,366 bears. A special 12-day extended firearm season in areas surrounding Pittsburgh and Philadelphia begins Monday, paralleling the statewide firearm deer season.

The next 10-year bear management plan, which Mr. Ternent is also writing, will attempt to further compartmentalize bear populations — slow the animal’s spread into residential areas while growing their numbers where there’s proper space and habitat.

“When the bear population gets to its biological carrying capacity, it affects litter size, body size,” said Mr. Ternent. “We’re not seeing any of those indicators today. I believe there’s room for more bears, but we need to balance that with the human social factor and limit the number of negative human-bear conflicts.”

Ursus americanus is unique among Pennsylvania’s indigenous species. A scavenger and a predator, a black bear will eat just about anything — berries, fruits, acorns, grass, carrion, corn and other agricultural products and even small or baby animals when they can catch them. Unfortunately for bears, they have a sweet tooth for human goodies and a weakness for easy pickings such as bird seed and unsecured trash.

Mr. Ternent said Pennsylvania bears start breeding at age 3 to 4, earlier than almost anywhere in North America. An adult sow (a female bear) generally weighs about 200 pounds, and boars (males) can grow to nearly four times that weight. Bears can live up to 25 years.

Statewide, the black bear range is expanding southward from the mountains into farm country and metropolitan counties. A 2008 poll conducted by Responsive Management, a nonprofit group that researches outdoors issues, found that Pennsylvanians are generally wary of bears. Forty percent of respondents said they were OK with black bears living in their county, but didn’t want them in their township or city, and 24 percent could tolerate bears in their township but didn’t want to see one in their yard. The poll found 21 percent were uncomfortable having black bears roaming wild anywhere in their county.

“Usually, when they’re in somebody’s yard they’re raiding a garbage can that wasn’t properly sealed, eating seed from a bird feeder, eating a bowl of pet food out on the porch,” said Tom Fazi, education officer for Game Commission’s southwest district. “You can’t punish people for not securing garbage can lids or leaving pet food outside. The bears are always on the losing end of that conflict.”

Using radio telemetry collars, habitat analysis and other tools, a three-year research project in Pennsylvania, New Jersey and West Virginia tracked the habits of suburban and urban bears. In the study, completed in 2011, Mr. Ternent and others studied den selection, reproductive success and movements of bears in areas with large human populations.

Residential and agricultural nuisance bear complaints are common in Pennsylvania — some 1,200 are filed each year. Mr. Ternent said the agency’s policy is to chase them away whenever possible. Trapping and relocating, he said, is usually not successful.

“We did a study on relocation in the 1980s,” he said. “If you move the animal less than 30 air miles, there’s a 100 percent chance of return. Sixty miles, a likely return. You have to relocate 100 miles or more to have no return.”

But in traveling long distances to find their way home, relocated bears get into conflicts with other territorial bears, raid farms and yards for food, cross streets and highways and have a higher mortality rate.

“There’s really no place in Pennsylvania where there’s an insufficient number of bears. Relocation is not an option. We look at it as a temporary solution, to buy us some time,” said Mr. Ternent. “We’d rather address what attracted the bear in the first place.”

Other means of bear control are impractical or worse, he said..

“Contraception is just not effective in a species where both sexes are polygamous,” he said. “There’s research, but nothing else is working now. Sometimes, our hands are really tied.”

Having expanded the bear population, Mr. Ternent said he’s reluctant to take nuisance bear control to a lethal level. No nuisance bears have been put down in southwestern Pennsylvania, he said. But elsewhere in the state, the Game Commission has had bears anesthetized and shot when they were terminally ill or injured, or showed unusual aggression toward humans.

“When we euthanize a bear, an element of the public is upset with that,” said Mr. Ternent. “But I think people realize that some bears can become habituated, equate humans with food and get too bold and aggressive around people. There are some things that can’t be tolerated.”

First Published: November 29, 2015, 5:00 a.m.