A few weeks ago, I joined members of the bear crew from the Maine Department of Inland Fisheries and Wildlife to survey a black bear sow in its den.
Approximately 80 of Maine’s 35,000 black bears are outfitted with tracking collars. Wildlife technicians visit the dens of the collared sows every winter to evaluate and record health information about the bears.
By monitoring the health and survival of these bears, biologists can infer what bears are experiencing across the state, information which helps them maintain a stable bear population.
Just north of Old Town, the bear crew (wildlife technicians Matt O’Neal, Adri Bessenaire and Nick Bartholemew) unloaded four snowmobiles. The wide tracks of the Ski-Doo Skandics were ideal for off-trail riding.
I jumped on the back of Adri’s sled and we slowly steered our way through the woods, stopping often to clear limbs and downed trees. Each time we stopped, I asked Adri a question and learned a little more about the bears of Maine.
Adri answered my questions patiently and explained that bears don’t always den underground. They will sometimes den in the hollow of a tree or in the open, on what looks like a large bird nest. I knew that bears were not true hibernators, but she explained that if bears hear us coming, they will run away.
After about an hour and nearly a mile, we stopped. Adri put her finger to her lips, signaling to be quiet. We were close to the den and would walk from here.
Pilots identified the approximate den location based on the signal from the sow’s tracking collar, and Matt was using telemetry to get a bearing toward the den. The crew gathered their gear and set off in the direction of the den.
The rest of us donned our snowshoes and waited quietly.
Twenty minutes later, someone with a radio received word that the sow was tranquilized and we could follow the crew’s tracks to the den.
When we arrived at the den, Matt was pulling a cub out and handing it to Nick. He recorded the sex of the cub and then tucked it into his wool jacket to keep it warm. The den was tidy and cozy — a hole dug under a downed tree, blanketed with snow. I could have easily walked past it. I thought of all the times I’d been out snowshoeing. Had I ever walked near a den?
The den swallowed Matt’s upper half; all I could see were his legs. He emerged with another cub; this one went into Adri’s jacket.
Adri was getting the sow’s new tracking collar ready. The collars not only allow the crew to locate denning sows, but they also provide information regarding the movement of the bear throughout the year and give off a mortality signal when the sow dies. That allows biologists to investigate its cause of death. The collars are made from breakaway leather, which will break over time or if the bear outgrows it.
Matt brought a third cub out of the den and handed it to Nick. By now all three cubs were squirming and squealing, but a fourth wimper came from the den.
“Are there four cubs?” Judy Camuso, Commissioner of DIF&W asked with surprise.
“Evidently!” Matt replied, chuckling, as he turned to stretch back into the den for the fourth.
Four cubs in a single den are about the maximum we get here in Maine. The fact this sow had four cubs means that it was healthy in the fall when going into the den.
Matt explained that it was sow No. 2,956 and joined the monitoring program as a cub 10 years ago. Last winter it had one newborn cub. Cubs den with their mother as yearlings (1-year-olds), so we expected it to be denning with last year’s cub. The fact that she had newborn cubs again this year means last year’s cub did not make it and she mated again last fall (called re-cycling).
Matt, Nick and Adri weighed, measured and sexed each cub, which ranged between two pounds and a chunky six pounds. Then they attached identification tags on each ear.
The next task was removing the sow from the den. Matt tied a rope around its legs and, with proper deadlifting form, braced his legs against the outside of the hole and gently pulled the sow to the surface. Nick, Matt and Adri laid it on a blanket and began evaluating its health. They attached a new tracking collar and weighed it — a healthy 190 pounds.
While the crew worked, the rest of us kept the cubs warm. They were living Velcro; their tiny claws stuck to our jackets, and they burrowed their faces into our necks and collars, before falling asleep against our chests.
After gathering the necessary information, the sow was returned to its den with an injection to reverse the anesthesia and the cubs were returned to their mother, anointed with cedar oil, to help mask our scent.
Next winter when the bear crew checks on sow No. 2,956, hopefully they find some yearlings denning with it. Female yearlings will be collared and join this important research and monitoring program.
DIF&W has captured more than 4,000 black bears since the monitoring program began in 1975. It is funded by hunters, with a portion of the money coming from hunting and fishing license sales, and a portion from a federal tax on firearms, ammunition and other hunting-related items.
It is the longest running study of its kind in the entire country and as climate and habitat change, it’s important to continue monitoring the health of this iconic Maine species.