Poop and prints could offer fresh insights on polar bear health
Researchers are developing ways to track polar bears through their scat and tracks, which might offer another means of monitoring the animals.
The work is part of BearWatch, a project that tries to find non-invasive ways of monitoring polar bears’ response to climate change. BearWatch combines genomics – the study of genes, including their interactions with each other and the environment – with Inuit knowledge. It includes universities, communities, hunters and trappers’ associations, the Inuvialuit Game Council, Canadian Rangers and governments.
The global polar bear population is divided into 19 subpopulations, monitored largely through aerial surveys. These surveys typically involve either counting animals from the air or shooting bears with a biopsy dart from a helicopter. The biopsy dart grabs a small sample of skin and fur before falling off the animal, which can then be used to genetically identify individual bears and estimate a subpopulation’s size.
These conventional monitoring techniques have their drawbacks, according to a paper published by BearWatch researchers last year.
Because they are expensive and logistically challenging, monitoring using these methods tends to be infrequent. As of 2019, only around a third of polar bear subpopulations had population estimates less than 10 years old, the researchers wrote.
Northern communities have also expressed concern over some techniques’ invasiveness, their potential to negatively impact bears and the lack of inclusion of Inuit knowledge.
Polar bear monitoring is not inclusive of northern communities, said Peter Van Coeverden de Groot, an adjunct professor at Queen’s University in Kingston and one of BearWatch’s four principal investigators. Other project leaders include Queen’s researchers Stephen Lougheed and Graham Whitelaw as well as the Nunavut government’s Markus Dyck, who passed away in 2021. Northern colleagues such as James Qitsualik, chairman of Gjoa Haven’s Hunters and Trappers Association; William Aglukkaq, a hunter from Gjoa Haven; and Leonard Netser of Coral Harbour have also been instrumental in the project, Van Coeverden de Groot said.
With conventional monitoring, the “lion’s share” of polar bear management money goes to helicopter companies, Van Coeverden de Groot told Cabin Radio after presenting an update on the project in December at ArcticNet, an Arctic research conference.
He and his colleagues hope that advances developed through BearWatch help redirect polar bear management funds into communities.
At a minimum, he said, “you’re giving the people the piece of the pie they’ve been cut out of.”
Data in dung
For the past few years, Van Coeverden de Groot and his colleagues have been assessing the kinds of information they can obtain from non-invasive samples.
To that end, they’ve been working with partners in Nunavut and the Northwest Territories to obtain samples of scat and snow from polar bear tracks. They’ve also been gathering tissue samples from harvested bears as a way to vet the information gleaned from scat. A set of samples that Van Coeverden de Groot calls “fecal socks” – essentially polar bears’ colons tied off on both ends – is unique in polar bear research and allows scientists to match feces to the bear it came from, he said.
Steven Baryluk, an NWT government manager of wildlife management, has contributed samples to the project for several years. So far, Baryluk said, the Northwest Territories has submitted more than 850 DNA samples, 450 fecal samples and more than 100 samples from polar bear tracks.
“It’s important to really acknowledge the work of the harvesters in the region,” he said.
Van Coeverden de Groot said scat, in particular, offers a rich profile of polar bear health.
“There’s an overwhelming amount of information we can get from scat that we cannot get, even if we tried, from aerial biopsy,” he said.
In the paper published last year, Van Coeverden de Groot and his colleagues developed a method that uses DNA in their scat to reliably differentiate individual bears, identify their sex and assess their genetic relatedness.
Poop might also offer clues about a bear’s exposure to contaminants. By analyzing their sets of tissue and fecal samples, Van Coeverden de Groot and his colleagues have been able to explore how levels of 110 contaminants in tissue relate to their levels in scat from the same bear. Although the research has yet to be published, he said, preliminary results suggest that for some contaminants, “what you get in the shit is the same as what you get in the fat, the liver or the muscle.”
Examining scat can provide information on a bear’s recent meals as well as its longer-term diet, Van Coeverden de Groot said. Collecting this information year after year could enable scientists to see how a bear might be changing its diet in response to climate change, information that would be impossible to obtain through other means, Van Coeverden de Groot said.
“Are you going to sit there and watch it in a kayak?” he said. “Bears are making decisions about their environment and we’re just guessing.”
Polar bear poo isn’t the only option for non-invasive monitoring.
The BearWatch team is in the early stages of developing techniques to collect DNA from tracks left in the snow, which could be used to genetically identify bears and determine their sex.
From 2020 to 2022, research teams in Coral Harbour, Nunavut, tested methods for collecting snow from paw prints like scooping them up with latex gloves, a sterilized snow knife or a trowel.
If the approach is shown to work, using paw prints for monitoring would be game-changing, Baryluk said. It might allow managers to obtain information about bears that aren’t typically harvested, he said, such as mothers and cubs.
Scat monitoring shows promise as well, he said, as some of the information from fecal samples appears to be a good approximation of what can be gathered from more invasive techniques.
Baryluk said the approach may miss some information, however, such as a polar bear’s age. The full extent of the technique’s capabilities is not yet clear.
Experts also still have to figure out how the new tools will fit into a polar bear management framework, Van Coeverden de Groot said. To do that, he said they need to know how much it costs to collect the data — a question that he and his colleagues are now working to answer.
Ultimately, Van Coeverden de Groot would like to see the new tools used in a ground-based survey across Canada, and potentially across polar bears’ entire range. He’d also like to see the tools rolled out in a way that is inclusive of Inuit communities and knowledge.
Throughout the project, harvesters were paid $50 to $75 dollars for collecting scat samples, which Van Coeverden de Groot said is not a long-term solution. “That’s not where we want to end up.” The idea, he said, is to make Inuit a much bigger part of the whole management process.