BRADFORD – Biologist Megan Brown is lying on her belly in the snowbank, her feet flailing as she tugs at the furry feet of a 150-pound mother bear. Mama has spent the past few months wedged into a surprisingly small crevice amid the roots of a tamarack tree, and, during this winter’s slumber, she bore three tiny cubs.

If not for the radio-collar that the female bear has been wearing for five years, Brown could have skied right by the cozy den blanketed in snow.

Throughout the state, in rural back yards, along the edges of potato fields and deep in commercial forestland, an estimated 23,000 bears are hibernating, blissfully unaware of the political battle being waged on their behalf.

In November, Maine voters will be asked to consider a referendum seeking to ban for ethical reasons bear trapping and bear hunting over bait or with dogs.

The Maine Department of Inland Fisheries and Wildlife is opposed to the ban, saying that bear management decisions should be made by wildlife professionals.

Maine’s biologists have been researching black bears since 1975 – in recent years, spending more than 2,000 hours and $72,000 on the effort. Their decades of data will be part of the arsenals used by both sides of the baiting fight.

But on this winter day, as state biologists weigh and measure the first newborn cubs of the 29th season of black bear research, politics are secondary to science.

With her arms in the den up to her shoulders, Brown finally succeeds in dislodging mama. Curled into an unconscious lump on the snow, the bear is surprisingly small. But if not for the double dose of tranquilizer administered by state biologists, her 2-inch claws and fierce protective instinct would be formidable.

The bear shudders in the bright cold of the morning, so the biologists wrap her on a tarp and shield her eyes with a leather glove.

Three cubs are zipped snugly into biologists’ jackets.

“She did well,” state biologist Randy Cross says of the 9-year-old sow.

Females can give birth every other year from the time they’re about 4 years old until they’re in their early 20s. Very young and very old sows typically have just a cub or two, while those in their prime reproductive years can have as many as four at a time.

Unlike many animals, bear cubs stay with their mother for two full years. Next winter these three cubs, each weighting 45 pounds or more, will den up with their mother one last time.

Cross and his team handle dozens of 6-week-old cubs every winter, then check in on them one year later to see which ones survive.

Humans are about the only predator capable of killing an adult black bear, but during their first year of life, bear cubs are surprisingly vulnerable to starvation and predators, Cross explains. On average, one cub in three dies before its first birthday.

“We’re always counting heads,” says Cross, who has worked on the bear study for 22 years. “I’ve watched [individual] bears grow from a cub to 20 years old.”

The biologists weigh this mother bear and check her teeth: She’s in good health. If a sow isn’t fat enough when she goes into hibernation in October or November, both the mother and her cubs could be at risk of starvation. All summer long, she feeds on berries, nuts, honey and grubs – bears aren’t particular.

“For six months, they eat all day, every day. That’s their job,” Cross says.

The three cubs are healthy too, still toothless and berry-blue-eyed at about 7 weeks of age.

A group of students from Unity College, who have come along to observe, crowd around as biologists outfit the trio with a pair of bright red ear tags for identification, as they’ve done with more than 2,000 bears over the years.

Then Cross places a bewildered cub into a canvas sack and dangles the contraption from a scale. He’s about 4 pounds – smaller than a housecat, and twice as noisy. Each little bear in turn yowls a noise that’s halfway between a meow and a squawk, until one of the biologists picks it up, tucking the velvety cub against his own body heat for a moment, before piling the cubs atop the mother.

“They’re really well-behaved because they’ve got full bellies,” Cross says.

The dazed cubs crawl around on their mother’s stomach, probing for her nipples in fur nearly as long as they are high, in an attempt to finish the meal that was so rudely interrupted.

Cross takes the opportunity for a little teaching; “They’re always dry, no matter how much it rains or snows on them,” he says, fingering the long exterior hairs and thick wooly undercoat of the mother bear’s fur. “It’s like Gore-Tex.”

In response to one student’s question about bears’ legendary stench, Cross leans over and inhales the vaguely doggy, woodsy scent.

“It’s a sweet smell,” he said.

With their experienced mother, these cubs have a better than average chance of surviving. If the two little females make it, they will stay close to home. The biologists likely will outfit them with radio collars so they can track the two and their daughters for the rest of their lives.

If their brother survives, he’ll have a much harder road. Males strike out for new territories at 2 years of age, and roaming puts them in contact with the two biggest dangers for bears: roads and people. During hunting season, more male bears are brazen enough to feed from bait stations, and, as a result, more tend to be killed.

“They’re removed from the population more [frequently] by every stupid thing they can do to get in trouble,” Cross says.

But despite a handful of natural deaths and more than 3,000 bears killed each hunting season, Maine’s bear population is on the rise, jumping 28 percent in the past decade to become the largest in the lower 48 states.

Cross believes that bear populations could be reaching a peak, with higher cub survival rates than had ever been predicted.

“I think we’re riding the top of the wave right now … in nature things go up, and then they go down. It’s a cycle,” he says.

The state predicts that a loss of baiting would result in a greater bear population explosion, while proponents of the referendum disagree. Either way, Maine’s bear study will continue.

“We’ll still be doing these surveys,” says Cross, who will be voting against the ban.

“It’s been my whole professional career,” he says. “All I think about is bears. I worry about bears.”