In 2010, Bonzo made national news. The 879-pound black bear from Pike County was legally killed in season with a crossbow. The man who illegally fed pastries to the bear for 17 years cried in front of the cameras that he felt like he had lost a beloved friend.
Much of the news coverage disparaged the hunter without mentioning that the crying guy had conditioned the bear to be unafraid of humans. And even if it hadn’t lumbered within 30 yards of the hunter, Bonzo likely would have died from high cholesterol and a heart attack.
New research into impacts on bears that eat human foods suggests other reasons the Pike County behemoth may have ultimately met an early death. A study published this year in the journal Scientific Reports found that wild black bears that eat human food hibernate less and age faster.
In Pennsylvania, despite the loss of thousands of acres of habitat since 1980, the population of black bears has grown from a couple of thousand to more than 20,000. The primary tool used in that conservation achievement was regulated hunting.
Now, the pendulum is swinging the other way. Pennsylvania wildlife managers believe that to mitigate negative human-bear contacts, bear population growth needs to be suppressed in some areas. In recent years the state Game Commission has liberalized bear hunting regulations, expanding the seasons and creating new opportunities to hunt in suburban areas where bears didn’t live before.
This year, Pennsylvania has doubled the number of statewide bear-hunting days, creating the state’s lengthiest bear-hunting opportunity since the 1930s. Hunters with general, archery and bear hunting licenses can help to keep bears out of the Pittsburgh and Philadelphia areas in a long season that started Sept. 21 and runs through Nov. 29. The big wildlife management area west of Philadelphia, 5B, has an archery bear season Oct. 5-Nov. 16.
The new statewide bear muzzleloader season begins Oct. 19 and ends Oct. 26, leading the way for an early firearms bear season Oct. 24-26 for junior and senior hunters, hunters who are on active military duty and some people with disabilities. A two-week archery season Oct. 28-Nov. 9 follows. The four-day general bear season Nov. 23-27 is followed in some areas by extended seasons, which, in eight Wildlife Management Units, have increased from four to seven days.
“It’s the largest suite of bear season changes ever approved in a single year,” said Mark Ternent, Game Commission bear biologist. “In most of the state, we’re going from 14 or 16 days of bear hunting to 32, from three Saturdays to seven, and we will start hunting bears almost two weeks earlier.”
In some urban areas scheduled for conservation hunts, wild bears have become proficient at stealing bird seed and pet foods left out overnight, tipping garbage pails and begging humans for a bite of whatever they’re having. But Mr. Ternent said the consumption of human food had little to do with the expanded conservation hunts.
“We regularly get reports of bears in populated areas. Wilkes Barre/Scranton is a good example,” he said. “The early season that occurs in 2B, 5B, 5C and 5D is not because there are greater amounts of human-associated food available or bear problems, but because they are places with limited bear habitat, high bear conflict potential and occur outside the primary bear range where we don’t want a large bear population.”
Raiding picnic baskets may present more than a nuisance and slight danger. The new study found other ways that frequent consumption of human foods can be bad for the bears.
“Human foods have become a pervasive subsidy in many landscapes and can dramatically alter wildlife behavior, physiology and demography,” wrote lead researcher Heather E. Johnson of the U.S. Geological Survey Alaska Science Center in the study conducted in the high mountains of Colorado. “Recent work has suggested hibernation may also slow the process of senescence, or cellular aging.”
When animals hibernate, they enter a state of torpor in which the body temperature drops and metabolic rates slow, helping the animal to survive in harsh conditions where food may be in short supply. Torpor actually slows the speed at which cells age.
In the study, the length of a key molecular marker for cellular age was measured and compared with markers in a control group.
“Our findings highlight how human food subsidies can indirectly influence changes in aging at the molecular level. … We found that bears that foraged more on human foods hibernated for shorter periods of time,” said Ms. Johnson.
Those results suggested that foraging on human foods could counteract the natural process by shortening hibernation. Whether fed intentionally to wild bears or stolen in a late-night trash raid, human foods may lack species-specific nutritional requirements, contain lethal compounds or spread diseases.
Consumption of human foods could also alter animal behavior, the study found, increasing the risk of injury or mortality in human-dominated landscapes.
“Highly accessible and predictable food subsidies can alter animal behavior, change population dynamics and restructure community assemblages and species interactions,” wrote Ms. Johnson. “Bears consuming more human foods may lose some of the long-term fitness advantages associated with hibernating.”
The research hasn’t yet been correlated with real-world hunting conditions. Nevertheless, the study suggests that bear hunters who hunt in areas where human foods may be more available could find bears experiencing increased aging, depleted fitness and behavioral changes.
Mr. Ternent of the Game Commission isn’t so sure.
“I wouldn’t say that eating human-related foods negatively impacts hibernation,” he said. “When we were conducting the Urban Bear Study [in 2010-13], we followed radio-collared bears captured in developed areas of Scranton, State College and Johnstown, and we observed denning dates that were comparable to bears in rural areas. They also used the same types of dens as rural bears.”
Denning dates can be altered by weather patterns, but Mr. Ternent said length of hibernation shouldn’t be affected.
“We know that natural food conditions vary by year, and in years when food is less abundant in the fall — for example, poor acorn crop years — bears tend to den earlier, and in years when fall foods are above average, bears tend to den later,” he said. “But again, I’m not sure human-related food availability varies annually like natural foods, or that it has resulted in changes to hibernation patterns.”
Although suburban bears may frequent the local trash dump, hunting in such places may be considered “baiting,” which is illegal in Pennsylvania. Mr. Ternent said bears seen at dumps in the summer may be long gone before the early bear seasons.
“The Urban Bear Study showed that bears trapped in highly residential areas during the summer tended to move away from those areas in the fall, which made them vulnerable to hunting but also likely increased their consumption of natural foods such as acorns,” he said. “In Pennsylvania, we know that nuisance bears trapped in highly developed areas during the summer get harvested at almost the same rate as rural bears, and we know that human-bear conflicts noticeably decline through late summer and fall. ... I suspect many of our bears that utilize human foods seasonally use them less in the fall because of the abundance and diversity of fall foods. If so, human foods may influence hibernation less than in places like Durango, Colorado.”
First Published: October 3, 2019, 12:00 p.m.
Updated: October 3, 2019, 2:26 p.m.