Scientists from the University of Saskatchewan (USask) have identified several polar bear dens during their research on grizzly bears.
Polar bear – stock photo. Image credit: Pixabay (Pixabay Free License)
Dr. Doug Clark (Ph.D.) has been inside many polar bear dens as a graduate student and in his former job as a park ranger.
So much so, in fact, that when Clark and his group of researchers identified a large number of previously undocumented dens north of Churchill, Manitoba – more than 100 kilometres further north than any other documented polar bear dens – he knew they belonged in polar bear habitats.
“We knew these were polar bear dens for a number of reasons. One, they were in peat deposits… but more specifically, we found polar bear hair,” Clark said.
USask has a long tradition of excellence in polar bear research, and Clark said the discovery of these new dens is positive for both researchers and polar bear populations. The discovery was recently published in an article in Arctic Science.
“For me, it’s a source of excitement,” he said. “There are a lot of legitimate concerns about this specific population of polar bears in western Hudson Bay.”
The discovery of the dens was completely serendipitous. Clark, an associate professor in USask’s School of Environment and Sustainability (SENS) and the school’s interim director, was in northern Manitoba as part of a research project investigating the expansion of grizzly bears in the region.
He said they identified what appeared to be a series of polar bear dens during a helicopter flight, which they were then able to confirm along the Caribou and Seal rivers.
“Polar bears have a lot more tricks than we usually give them credit for,” he said. “Even though it’s complicated to understand what’s going on, to see polar bears doing something like this, whether we’ve overlooked it or whether it’s new or not, they’re doing something that we – the conventional scientific narrative – wouldn’t expect.”
Polar bears living in this population’s main denning area — 120 kilometres south of these newly described dens — travel an average of 50 to 80 kilometres inland to build dens in the banks of permafrost-covered rivers and lakes. As Clark says, pregnant polar bears and female polar bears with cubs will travel this far, at least in part, to avoid males, because the larger males will eat the cubs.
While these dens were new to the researchers, they were not to the community. Clark said that upon their return, many Churchill residents confirmed seeing polar bear tracks with their cubs in the spring, heading inland toward the sea ice along these rivers. With this insight from community members, the researchers believe some of these dens were maternity dens where females would give birth. Other dens may simply have been used temporarily to keep cool during the region’s short but warm summers.
Clark said it’s not yet clear how long the newly identified dens have been there. Some dens farther south date back more than 250 years.
“It matters whether the dens are new or not. If they’re new, then something is changing, but if they’re not, then maybe some of that bear population has been overlooked in studies so far,” Clark said.
Many of these “new” dens are located in an Indigenous protected area monitored by the Seal River Watershed Alliance (SRWA). Stephanie Thorassie, executive director of SRWA, said connections between researchers and communities play an important role.
“We are excited about the information that the scientific community is finding. Ultimately, these partnerships with our communities help reaffirm the knowledge that our land users are talking about, and that feels good,” Thorassie said. “We look forward to continuing these partnerships by combining science with our knowledge to better understand our traditional lands and home.”
Clark said the next steps will be to work with alliance colleagues to determine the best approach to determining how many of these dens are being used, how often and by which bears.
“My hope is that our work to understand what’s going on and to better understand the polar bears that are nesting in this area can be done with the guidance and leadership of the community,” he said. “I’m really proud of all of the collaborations and relationships that have made this research possible.”
Écrit Par Matt Olson
Source: The University of Saskatchewan
Originally published in The European Times.
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