Grizzly bears in the central coastal region of British Columbia.
Michelle Valberg
The bears and Indigenous humans of coastal British Columbia have more in common than meets the eye. The two have lived side by side for millennia in this densely forested region on the west coast of Canada. But it’s the DNA that really stands out: A new analysis has found that the grizzlies here form three distinct genetic groups, and these groups align closely with the region’s three Indigenous language families.
It’s a “mind-blowing” finding that shows how cultural and biological diversity in the region are intertwined, says Jesse Popp, an Indigenous environmental scientist at the University of Guelph who was not involved with the work.
The research began purely as a genetics study. Grizzlies had recently begun to colonize islands along the coast of British Columbia, and scientists and Indigenous wildlife managers wanted to know why they were making this unprecedented move. Luckily, in 2011, the region’s five First Nations set up a collaborative “bear working group” to answer exactly that sort of question. Lauren Henson, a conservation scientist with the Raincoast Conservation Foundation, partnered with working group members from the Nuxalk, Haíɫzaqv, Kitasoo/Xai’xais, Gitga’at, and Wuikinuxv Nations to figure out which mainland grizzlies were most genetically similar to the island ones.
Henson used bear hair samples that researchers involved with the working group had collected over the course of 11 years. To get the samples, the team went to remote areas of British Columbia—some of them only accessible via helicopter—and piled up leaves and sticks, covering them with a concoction of dogfish oil or a fish-based slurry. It “smells really, really terrible to us, but is intriguing to bears,” Henson says.
The researchers then surrounded this tempting pile with a square of barbed wire, which harmlessly snagged tufts of fur—and the DNA it contains—when bears came to check out the smell. In all, the group collected samples from 147 bears over about 23,500 square kilometers—an area roughly the size of Vermont.
Henson and her colleagues then used microsatellite DNA markers—regions of the genome that change frequently compared with other sections—to determine how related the bears were to each other. The scientists found three distinct genetic groups of bears living in the study area, they report this month in Ecology and Society.
DNA analysis reveals three distinct genetic groups of grizzly bears, which align with the boundaries between Indigenous language families (gray lines).
L. H. Henson et. al. Ecology and Society, 26(3): 7, 2021
But they could not find any obvious physical barriers keeping them apart. The boundaries between genetic groupings didn’t correspond to the location of waterways or especially rugged or snow-covered landscapes. It’s possible, Henson says, that the bears remain genetically distinct not because they can’t travel, but because the region is so resource-rich that they haven’t needed to do so to meet their needs.
One thing did correlate with the bears’ distribution, however: Indigenous language families. “We were looking at language maps and noticed the striking visual similarity,” Henson says. When the researchers analyzed the genetic interrelatedness of bears both within and outside the area’s three language families, they found that grizzly bears living within a language family’s boundaries were much more genetically similar to one another than to bears living outside them.
The findings don’t surprise Jenn Walkus, a Wuikinuxv scientist who co-authored the study. Growing up in a remote community called Rivers Inlet, she saw firsthand that humans and bears have a lot of the same needs in terms of space, food, and other resources. It would make sense, she says, for them to settle in the same areas—ones with a steady supply of salmon, for instance. This historic interrelatedness means Canada should manage key resources with both bears and people in mind, she says. The Wuikinuxv Nation, for example, is looking into reducing its annual salmon harvest to support the bears’ needs, she notes.
Lauren Eckert, a conservation scientist at the University of Victoria who was not involved with the study, agrees that the findings could have important implications for managing the area’s bears. It’s “fascinating” and “really shocking” work, she says. The resources that shaped grizzly bear distribution in the region clearly also shaped humans, Eckert says, “which I think reinforces the idea that local knowledge and localized management are really critical.”