Keeping track of black bears
With a sharp eye and steady hand, Mike Evans pinched tweezers around a single black hair hooked around a prong of barbed wire strung deep in a forest in the state's northwest corner.
"The follicle is the best part of the hair to get DNA out of, so I try not to break it," said Evans, crouched low beside the wire as he slipped the hair into a small brown envelope, which he then sealed and labeled.
The dense shade of the forest notwithstanding, he and his assistant, Jason O'Connor, had painstakingly examined each barb to locate five single bear hairs - treasures so slight they were invisible to any gaze less than laser-true.
Evans, a doctoral student in wildlife biology at the University of Connecticut, plucked the hairs one morning earlier this month at one of about 10 barbed wire enclosures he and O'Connor, a master's student in wildlife biology, visited that day. This spring, Evans had set up about 50 of the 16-by-16 enclosures at state forest, land trust and private lands in the northwest corner, the epicenter of the state's growing black bear population.
Over the next three years, the research project will expand to cover their entire range.
"We'll be sampling a wide geographic area, based on where we know we have lots of bears and areas where we are confident there are bears because there is good habitat, but have not had a lot of reported bear sightings," said Tracy Rittenhouse, who is heading the project as assistant professor of wildlife ecology at UConn. "The population has been moving from the northwest corner south and now it's up against West Hartford and Avon - places of high human density."
The project got under way this spring, commissioned by the state Department of Energy and Environmental Protection, to produce better estimates of the bear population and distribution.
The purpose, said DEEP wildlife biologist Paul Rego, is to help inform ongoing discussions about whether the bear population has reached the point where a hunting season is needed to keep it in check. That would require a legislative act, because while DEEP can establish regulations for hunting specific species, it cannot set fees for licenses without legislative approval, Rego said.
Return of the bears
Once extirpated in most of the Northeast, black bears have been re-establishing themselves in recent decades throughout their historic range as lands once clear-cut and turned into farmland have returned to forest. Several other states have recently turned to hunting as a means of controlling the bear population.
Whether Connecticut wants to follow the same course is yet to be decided, but in the meantime, residents can appreciate that having bears is a positive indicator of the health and diversity of habitat in this small state, Rittenhouse said.
"We have all the amenities of city life in Connecticut and forests healthy enough to support bears," she said. "I think that's a great thing for Connecticut to have."
Current estimates, based on reported bear sightings and data from bears that have been tagged and fitted with radio collars, put the population at 400 to 500 bears.
"But the population's been doubling every five to seven years" with no signs of slowing down, said Dennis Schain, DEEP spokesman.
By rough estimates, DEEP spends more than $250,000 a year responding to nuisance bear calls, in the form of staff time and resources of Environmental Conservation officers and wildlife biologists who tranquilize, trap and relocate them, Schain said. In the last fiscal year, DEEP received 120 calls from the public about problem bears.
About 20 bears a year are killed by cars on Connecticut roads, Rego said.
"I'm not sure I've ever gotten a call from somebody suggesting they want to see more bears," he said. "But we receive calls almost daily from individuals who want fewer bears. It's obviously a growing and spreading population, and there are growing numbers of conflicts with humans. Some people are worried about their children's or their pet's safety. We have bears that have broken into houses and damaged fruit trees."
While there have been no reports of injuries to humans from the state's black bears, Rego said, more of these large, powerful omnivores seem to be adapting to life in proximity to populated areas, drawn to feasts found in bird feeders, trash cans and pet food left outside. Rittenhouse said that while black bears are not aggressive toward humans, it's prudent to be wary around them.
"Black bears try to teach their cubs escape behavior when they're threatened, to go up a tree right away," she said. "But they will bluff charge if they're frightened. They are animals and they're stronger and faster than I am. You don't want to give a bear a bear hug."
When a nuisance bear is trapped, wildlife officials take it to the nearest suitable habitat within 10 miles, Rego said, and employ "aversion conditioning" techniques such as rattling the cage and firing shotguns to teach it to stay away from humans.
DEEP is also considering adding one or more Karelian bear dogs to its arsenal, Schain said. Originating in Finland, these dogs were bred to chase bears. The agency has had recent discussions with an out-of-state breeder about purchasing one, he added.
"If we had 10,000 well-behaved bears in Connecticut, people would probably be content," Rego said. "But we have bears that have become very habituated to populated areas. They don't run when they see a person, or when someone fires a shotgun into the air."
Scents attract bears
The bear hair research will contribute to the state's analysis of its bear population in multiple ways, Rittenhouse said. Through DNA sequencing of each hair sample collected - Evans estimates he's snared 75 to 100 thus far - researchers will be able to identify how many individual bears visited each site and use that information to extrapolate the population in a given area around each enclosure. Hair samples will also be collected and analyzed by DEEP staff who trap nuisance bears.
"We'll be able to compare samples that potentially could give us information on where the bears are traveling," Rittenhouse said. "We're interested in what habitats the bears are using and how they're moving across the landscape."
Evans spent last week at the University of Missouri learning the DNA sequencing techniques he will use at UConn labs. The bear hair collection and sequencing project, Rittenhouse said, has been done in other states, relying on a simple but ingenious design.
"The most fascinating thing is how much information we can gain without the bears knowing it," she said.
First, Evans, said, he selected sites for the enclosures based on proximity to good food sources, such as wetlands and oak forests with abundant acorns, and places near recent bear sightings.
Barbed wire enclosures were rigged 2 feet off the ground around rings of trees. In the center of each, he would place a pile of sticks slathered with one of four aromatic lures - beaver castor, anise oil, fish oil and a commercial product developed for bear hunters. He also suspended a scent-soaked rag from a tree limb so the smell would waft into the air beyond the immediate vicinity.
No food is left at the site. That would reward the bears and skew the results, Evans said.
"But I use a variety of different scents so they don't get conditioned to thinking there is no point in coming to the enclosure," Evans said, as he and O'Connor approached a site in Sunny Brook State Park in Torrington, a bright yellow "Black Bear Survey Site: Please Do Not Disturb" sign posted on a nearby tree.
When the bear enters the enclosure to investigate, it scrapes up against the barbed wire, sometimes leaving hairs behind. Cameras with shutters set to go off automatically when movement is detected at the sites have captured images of curious bears visiting the enclosures, but Evans has never seen one.
"At one of the sites, there was a photo of a bear taken just seven minutes before I came to check on it," he said. "But I have come across scat and tracks."
The field work involves a lot of off-trail bushwhacking, clambering over stone walls and fallen trees, fording streams and slogging through swampy areas to reach the sites, and then meticulous examination and re-examination of every barb on each wire. Only about one in five sites yields hairs, Evans said.
"There's a lot less glamorous stuff that goes on for every interesting result," he said, as he headed back to his truck to drive a few miles to the next site, at John A. Minetto State Park in Torrington and Goshen.
After removing a hair, Evans trained a lighter flame on the barb, "so that anything I missed, I won't see next time."
For Evans, the project meshes with his ongoing interest in wildlife-human interactions and ways that both adapt to each other's presence.
"Connecticut hasn't been bear country for a long time, and certain human behavioral changes might have to become part of the routine," he said.
Rittenhouse agreed, adding that whatever the state decides about whether to allow bear hunting, residents can learn to live with bears.
"It's possible for Connecticut to have a happy human population and a happy bear population at the same time," she said. "The state clearly has the resources to do that."
MOST VIEWED MEDIA
MOST DISCUSSED STORIES