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Colorado Parks and Wildlife researchers Tana Verzuh, left, David Lewis, center, and lead researcher Heather Johnson, right, examine a sleeping black bear near her hibernation den outside Durango on Friday morning.
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Grin and bear it
Wildlife researchers lead ursine expedition just outside Durango
by Tracy Chamberlin
Not far from the borders of the city and just a stone’s throw from paved roads, a 10-year-old local resident made her home underneath an unassuming boulder.
Feed flowers not bearsIn an effort to keep bears where they belong, Bear Smart Durango is partnering with the Durango Botanical Society and AJ’s Greenhouse on a unique program whereby residents can exchange their birdfeeders for flower baskets. |
Her name is B122, and she’s part of a multi-year bear study meant to examine the habits of black bears in Southwest Colorado and how human development affects their behaviors.
Heather Johnson, wildlife researcher with Colorado Parks and Wildlife, is the lead researcher on the project and recently served as the fearless leader of an ursine expedition to check on B122 and her new family.
Part wildlife biologists and part intrepid tagalongs, the band of bear-seekers included myself as well as a Telegraph photographer.
After a short hike, the group came upon the rock grouping where B122 had made her home last winter. Johnson and her team administered a sedative to the groggy bear and covered the den opening with their backpacks, giving her solitude as the sedative set in. Everyone stood quietly outside, waiting.
That’s when we heard it. The faint call of baby bears.
Once their mom was in her tranquil state, the packs were removed and the babies, born less than two months ago, were pulled out of the den. First one, then the other. And then one of the researchers called out, “It’s triplets!”
They moved quickly and decisively, getting the three siblings from the den and into the warmth and darkness of winter coats.
The first of the two girls earned the name Pooh. Not for any similarity to the red-shirted honey lover, but because of her tendency to relieve herself. The boy was named Steve by one of our co-adventurers.
The third member of the litter didn’t officially receive a name, not until now. I decided to call her Aurora. Because in many ways, it was the dawn of a new day.
The first time the sun shined on Aurora was the moment she was moved from the darkness of the den to the inside of my North Face jacket.
All the babies weighed between 6 to 8 pounds. The 205-pound mom, who had already lost between 30 and 40 pounds since first settling in for the winter, was in good health.
It’s the second time she’s given birth. B122 was captured in September 2013 with two cubs at her side; however, the following winter researchers found her den only to discover only one of those cubs survived to be a yearling.
Johnson and her co-workers will use the tracking collar to locate her again next winter. They’ll update her weight and download the data from the collar, along with a litany of other evidence for the study. And, of course, they’ll check in on those three baby bears.
Johnson said, on average, the little ones have just a 40 to 60 percent chance of surviving the first year. Once they’ve made it past that milestone, they’ll head off into the forest to start their own adventures.
Our trip marked the second time Johnson has seen triplets this season. Over the past four years of the bear study, she said they’ve observed seven sets all together.
Triplets are not a common sight among black bears in the western United States, showing up only 13 percent of the time. Twins are much more common, popping up 74 percent of the time.
“We have only seen triplets after moderate and good natural-food years,” Johnson said.
They expect the same to be true this year. The number of triplets born this season is related to the banner food season last year, and with seven dens yet to visit,
that number could only go up.
 Telegraph reporter Tracy Chamberlin holds one of three baby bears found inside the den./Photo by Jennaye Derge |
Currently, more than 600 bears have been captured in Southwest Colorado, 311 tagged as a part of the study and 70 adult females fitted with collars. The collars log the bear’s location every hour from March 15 - Dec. 15, when they’re likely to be out and about.
During the winter months, from Dec. 15-March 15, the bears are stationary in their dens and the collar goes into its own hibernation mode to save battery power. During these months, the collar logs in just one location per day.
Over the multi-year bear study, which has been extended to six years over the original five, researchers plan to publish papers, utilizing data collected from the field and the collars. The first of those papers, which addresses a bear’s tendency to stick to its natural food source, is currently in the revision process and will hit the shelves later this year.
There’s an assumption that when bears discover a human food source, they always use it. But Johnson said data disputes that. “That’s not what we see at all,” she said.
Data collected and analyzed from studies in Durango, Aspen and Lake Tahoe, Calif., suggests that black bears actually calculate the cost benefit of human development.
For them, it’s a trade off.
According to Johnson, bears aren’t returning to trash cans and birdfeeders simply because those human food sources are familiar or easy. It’s more of subsidy, a way to supplement their diet when natural food sources are scarce.
“Bears are making really complex decisions about how and when they choose developed habitats,” she said.
The data shows bears shift their behavior patterns to adjust to human activity.
In the wild, they typically feed during the day; however, they become nocturnal when feeding around humans, seemingly in an attempt to minimize their interactions with the bi-peds.
Of course, that doesn’t mean it’s a good idea to leave garbage on the front porch if it’s been a banner year for acorns and berries.
“Our hope is that as bears learn they don’t have access to human foods, they won’t choose to use it,” Johnson said.
The mother of three we met is an example of the findings the paper addresses. The location data downloaded from her collar shows her using a mix of human and natural food sources.
“How she uses habitat in any given year likely depends on a whole suite of factors,” Johnson said. Natural forage, the time of year and her experience with humans are all a part of her decision-making process.
“We share the landscape with these critters,” Johnson said. “To do that successfully, it means we are going to have to change our behavior.”