In order to protect animals like polar bears from certain threats, whether pollution, climate change, or people, we have to know their behavior. And in order to learn where polar bears live, how they move around, and how many there are, we have to track them. A group of researchers have been working on a new, less invasive way to do this with tags that stick to their fur—rather than collars around their necks or ear tags pierced through their skin.
Called “Burr on Fur,” the initiative to improve polar bear tracking technology began as a challenge posed by conservation nonprofit Polar Bears International to scientists at 3M, the company behind Post It Notes and a range of other industry and consumer products. 3M experts developed a series of trackers that stick to the animals’ fur, and researchers have recently completed trials putting the tags on wild polar bears—with promising results.
Tracking polar bears
Tracking polar bears can be a challenge. To start with, they live in remote areas in the harsh environment of the Arctic, which can make research both difficult and expensive. “We can’t see them for the vast majority of their lifecycle,” says Geoff York, senior director of research and policy at Polar Bears International.
The only way we get information on their movements and habitat use is by tracking them. That information then helps researchers understand polar bear populations, which can be important for understanding the effects of climate change (which has been reducing the Arctic sea ice that polar bears rely on), or even localized pollution. “How many bears is an oil spill likely to impact? If we don’t have movements data, we can’t really say,” York says.
But the actual technology of trackers poses issues, too. Researchers have long used GPS collars, fitted around the bears’ necks—but those can only be used on female bears. Male polar bears have cone-shaped heads, where their necks are as wide as their heads, meaning the collars just slip off. “Subadult” bears, which are still growing, also can’t be fitted with collars, because they could become too tight as the bears get bigger. Researchers also use ear tags, but those are invasive, permanent, and can risk injuries.
How Burr on Fur began
In recent decades, York says, there has been a growing pressure on biologists broadly to find less invasive ways to study animals. “Amongst my polar bear colleagues, we are constantly asking ourselves that same question: how can we do this better? How can we do this with less impact?” he says. “And this project is an example of that manifested.”
Wildlife research, though, doesn’t always get the best access to new technology, in part because there’s little money in the field. Around 2006, at an International Bear Association meeting, researchers began looking at ways to attach tags to fur, and how they could partner with companies to do that.
By chance, one of York’s colleagues was the son of a researcher at 3M, which has an internal science competition that looks for projects on how to take 3M’s expertise and apply it to real world problems. 3M scientists designed and tested the trackers in simulated Arctic conditions, like cold rooms and salt water tanks, and eventually tested in zoo settings as well.
3M “did all the heavy lifting in terms of design and conception of the tags,” says Tyler Ross, a researcher at York University and lead author of a recent paper, published in the journal Animal Biotelemetry, on the Burr on Fur tag trials in the wild. From there, Ross and other researchers put the tags to the test on wild polar bears along the coast of Hudson Bay, Canada. They looked at how long the Burr on Fur tags stayed attached, and how the resolution of the data they collected compared to conventional tracking tags.
Researchers tested three designs (and compared them to ear tags) on 58 wild bears: the Pentagon tag has five holes at its corners which tufts of fur can be pulled through; the SeaTrkr tag is oval shaped with 10 holes; and the Tribrush tag is shaped like a triangle, with tubes along its side that the fur can be twisted into to hold it in place. The SeaTrkr was the top performing tag, lasting an average of 58 days and with the best GPS accuracy. The Tribrush tags lasted an average of 47 days, but varied—one fell off after just two days, while another stayed on for 114 days. (Polar bears can dislodge trackers when rubbing up against rocks or the thick brush on land.)
What’s next for wildlife research
The Burr on Fur polar bear trackers are designed to be temporary. That’s in contrast to ear tags, which are permanent. Because polar bears have such huge home ranges, when researchers put an ear tag on a bear, they may never see that bear again to remove it. (For collar trackers, female polar bears do sometimes slip them off themselves.) The fur tags, though, were designed to be minimally invasive and fall off. In theory, they could last a whole year, through to when the polar bear molts, which is sufficient for a lot of research.
To tag the bears, the process is similar to other trackers: Researchers fly helicopters along the coast looking for polar bears, and then sedate them from the helicopter. They then land and apply the tags. After those wild bear trials, researchers are refining the Burr on Fur designs. They also want to test them over different times of the year to see how different environmental stressors impact the tags (their trials were done in the spring).
So far, researchers say the tags are really promising—and they could open up new information about polar bears. “Virtually everything we know about polar bear habitat selection and behavior is from adult females. There is some evidence to suggest that male bears differ in their behavior and where they’re moving during specific times of the year,” Ross says. “These tags can help us get a better glimpse into what the male bears [and subadult bears] are doing at different times of the year.”
These trackers could also mitigate human-bear interactions. As sea ice declines, researchers expect to see more interactions between bears and people, which means we need to monitor bears that get too close to towns, and track their movements in order to warn people. These wandering bears tend to be subadult. The shorter life of the Burr on Fur trackers would be a less expensive and invasive way to do that short-term monitoring.
The trackers could also work on other animals, making all sorts of wildlife work less invasive. “We’ve since been contacted by black bear people, moose people, beaver reintroduction groups,” York says. “Anything with fur, this is potentially useful for—and hopefully will spur continued innovation and evolution of this style of tag that’ll improve it for everyone.”