When they’re born, polar bears are toothless and blind, and they weigh roughly a pound. But over time—thanks to lots of fat-rich milk and protection from their mother—these helpless cubs grow to become large, powerful predators that are perfectly adapted for their Arctic environment. Though temperatures can dip to minus 50 degrees Fahrenheit in the winter, the massive marine mammals—which live in Canada, Norway, Russia, Greenland and Alaska—stay warm with a thick layer of body fat and two coats of fur. Their huge paws help them paddle through the icy water and gently walk across sea ice in search of their favorite meal, seals.
Their size, power, intelligence and environmental adaptions have long intrigued humans living in the north, including many Indigenous communities, such as the Inuit, the Ket and the Sámi. Biologists are curious about Ursus maritimus for many of the same reasons.
“Bears are fascinating,” says B.J. Kirschhoffer, director of conservation technology at Polar Bears International. “For me, when standing on a prominent point overlooking sea ice, I want to know how any animal can make a living in that environment. I am curious about everything that makes them able to grow to be the biggest bear by living in one of the harshest places on this planet. There is still so much to learn about the species—how they use energy, how they navigate their world and how they are responding to a rapidly changing environment.”
Today, researchers and conservationists want to know about these highly specialized marine mammals because human-caused climate change is reshaping their Arctic habitat. The bears spend much of their time on sea ice hunting for seals. But as temperatures in the Arctic rise, sea ice is getting thinner, melting earlier in the spring and forming later in the fall. Pollution and commercial activity also threaten the bears and their environment. An estimated 26,000 polar bears roam the northern reaches of the world, and conservationists worry they could disappear entirely by 2100 because of global warming.
But investigating mostly solitary creatures who spend much of their time wandering around sea ice, in some of the most remote and rugged places on the planet, is expensive, logistically challenging and dangerous to researchers. For help, scientists are turning to technology. These five innovations are changing the way they study polar bears.
Sticky tracking devices
Much of what scientists know about polar bears comes from tracking female members of the species. This is largely due to anatomical differences between the sexes: Males have small heads and thick necks, which means tracking collars can easily slip right off. Females, on the other hand, have larger heads and thinner necks.
Neck collars are out of the question for males, and they’re not ideal for young bears, which can quickly outgrow the devices. Other options—like implants—require the bears to undergo minor surgery, which can be potentially risky to their health. Ear tags don’t require surgery, but they are still invasive. They’re also permanent, and polar bear researchers strive to make as minimal an impact on the bears as possible. How, then, can scientists attach tracking devices to young bears and male polar bears?
This was the challenge put to innovators at 3M, the Minnesota-based company that makes everything from medical devices to cleaning supplies to building materials. 3M is particularly good at making things sticky—its flagship products include Post-it Notes and Scotch Tape.
Jon Kirschhoffer spent his nearly 40-year career at 3M as an industrial designer, developing novel solutions to complex problems just like this one. So when B.J. Kirschhoffer, his son, started chatting about the need for a new, noninvasive way of attaching trackers to polar bears, Jon’s wheels started turning. He brought the problem to his colleagues, who set to work studying polar bear fur and building prototypes.
In the end, they landed on two promising “burr on fur” approaches. One device uses three bottle brushes—small, tubular brushes with a long handle made of twisted metal wire that could fit inside the neck of a skinny bottle—to grab onto clumps of a sedated bear’s fur. They also have the option of applying a two-part epoxy to the bottle brushes to help hold the bear’s fur more securely. Scientists and wildlife managers can use the brushes to firmly attach a triangular plate that contains a tracking device between the animal’s shoulder blades. In tests, the researchers have sedated the animals before attaching the trackers, but some zoos are training their bears to accept the tags while fully alert.
“It’s like a burr: You twist and entangle the fur in the bottle brush, then bend over the handle so it doesn’t untwist,” Jon says. “We do that on three sides and put a little protective cap over it so it’s less likely to get snagged on willows and brush and other things that bears walk through.”
The other option draws inspiration from the process hair stylists use to attach hair extensions to their human clients’ heads. This pentagonal design involves extending a loop of a fishing leader down through five metal ferrules, or tubes; lassoing some hair on a sedated polar bear; and pulling it back through. Scientists can then use pliers to squeeze and crimp the hair in place.
Researchers are testing both devices on wild bears in Churchill, Manitoba, and on bears housed at zoos and aquariums. The verdict is still out on which option is better, and Polar Bears International expects the testing phase to last several more years. Ultimately, by making design modifications based on their experimental learnings, they hope to tweak the devices so they will stick to the bears’ fur for at least 270 days, which is the lifespan of the tracking devices themselves.
But even if they can’t get the sticky devices to stay attached to bears for the full 270 days, the gadgets will still be useful for gathering some amount of data on males and young bears, which is currently lacking. They’re also promising for short-term tracking situations, such as “when a bear has entered a community, been captured and released, and we want to monitor the animal to ensure it doesn’t re-enter the community,” says B.J.
“Bear-dar” detection systems
When humans and polar bears meet, the encounters can often end in tragedy—for either the bear, the human or both. Conflict doesn’t happen often, but global warming is complicating the issue. Because climate change is causing sea ice to form later in the fall and melt earlier in the spring, the bears are fasting longer. And, with nowhere else to go, they’re also spending more time on land in the Arctic, where an estimated four million humans live. Some are even seeking out easy calories from garbage dumps or piles of butchered whale remains.
Scientists counted 73 reports of wild polar bears attacking humans around the world between 1870 to 2014, which resulted in 20 human deaths and 63 human injuries. (They didn’t include bear outcomes in the study.) After analyzing the encounters, researchers determined that thin or skinny adult male bears in below-average body condition posed the greatest threats to humans. Female bears, meanwhile, rarely attacked and typically only did so while defending their cubs.
To prevent human-bear encounters, scientists are developing early-warning radar detection systems they’ve nicknamed “bear-dar” to help alert northern communities when a bear is getting close. A handful of promising prototypes are in the works: Some teams of researchers are building the systems from scratch, while others are riffing off technologies that are already in use by the military. They all use artificial intelligence models that may be able to discern approaching bears. Scientists have tested the systems in Churchill, Manitoba, and are now tweaking the A.I. models to be more accurate.
“We’ve already established that the radar sees everything,” B.J. Kirschhoffer says in a statement. “Being able to see is not the problem. Filtering out the noise is the problem. … Ideally, we can train them to identify polar bears with a high degree of certainty.”
As the systems are still in testing, they do not alert members of the community or professional responders. But, eventually, communities may develop custom responses depending on the alerts, says Kirschhoffer.
“For instance, if a bear-like target is identified 200 meters out, send a text message,” he says. “If a bear-like target is identified 50 meters out, blink a red light and sound a siren.”
Synthetic aperture radar
Scientists are highly interested in polar bear dens—that is, the cozy nooks female bears dig under the snow to give birth to cubs—for several reasons. Denning, which occurs each year from December to early April, is the most vulnerable time in the life of youngsters and mothers. Though they’re accustomed to covering huge amounts of territory to find prey, mother bears hunker down for the entire denning period to protect their cubs from the Arctic elements and predators. Studying bears at den sites allows researchers to gather important behavioral and population insights, such as the body condition of mothers and cubs or how long they spend inside the den before emerging.
Scientists also want to know where dens are located because oil and gas companies can inadvertently disturb the dens—and, thus, potentially harm the bears—when they search for new sources of fossil fuels. If researchers and land managers know where polar bear dens are located, they can tell energy companies to steer clear.
But finding polar bear dens on the snowy, white, blustery tundra is a lot like finding a needle in a haystack. Historically, scientists have used low-tech methods to find dens, such as heading out on cross-country skis with a pair of binoculars or using dogs to sniff them out. But those options were often inefficient and ineffective, not to mention rough on the researchers. For the last few years, scientists have been using a technology known as forward-looking infrared imagery, or FLIR, which involves using heat-sensing cameras attached to an aircraft to detect the warm bodies of bears under the snow. But FLIR is finicky and only works in near-perfect weather—too much wind, sun or blowing snow basically renders it useless. What’s more, if the den roof is too thick, the technology can’t pick up the heat inside. Tom Smith, a plant and wildlife scientist at Brigham Young University, estimates that aerial FLIR surveys are 45 percent effective, which is far from ideal.
But a promising new technology is on the horizon: synthetic aperture radar (SAR). Affixed to an aircraft, SAR is a sophisticated remote-sensing technology that sends out electromagnetic waves, then records the bounce back, to produce a radar image of the landscape below. SAR is not constrained by the same weather-related issues as FLIR, and it can capture a huge swath of land, up to half a mile wide, at a time, according to Smith.
Scientists are still testing SAR, but, in theory, they hope to use it to create a baseline map of an area during the summer or early fall, then do another flyover during denning season. They can then compare the two images to see what’s changed.
“You can imagine, with massive computing power, it goes through and says, ‘These objects were not in this image before,’” says Smith.
Getting an accurate headcount of polar bears over time gives scientists valuable insights into the species’ well-being amid environmental changes spurred by climate change. But polar bears roam far and wide, traveling across huge expanses of sea ice and rugged, hard-to-reach terrain in very cold environments, which makes it challenging, as well as potentially dangerous and expensive, for scientists to try to count them in the field. As a result, researchers have taken to the skies, looking for the bears while aboard aircraft or via satellites flying over their habitat. After snapping thousands of aerial photos or satellite images taken from space, they can painstakingly pore over the pictures in search of bears.
A.I. may eventually help them count the animals. Scientists are now training A.I. models to quickly and accurately recognize polar bears, as well as other species of marine mammals, in photos captured from above. For researchers who conduct aerial surveys, which produce hundreds of thousands of photos that scientists sift through, this new technology is a game-changer.
“If you’re spending eight hours a day looking through images, the amount of attention that a human brain is going to pay to those images is going to fluctuate, whereas when you have a computer do something … it’s going to do that consistently,” Erin Moreland, a research zoologist with the National Oceanic and Atmospheric Administration, told Alaska Public Media’s Casey Grove in 2020. “People are good at this, but they’re not as good at it as a machine, and it’s not necessarily the best use of a human mind.”
To that same end, researchers are also now testing whether drones work to capture high-resolution images and gather other relevant data. Since they don’t require onboard human pilots, drones are a safer, more affordable alternative to helicopters; they’re also smaller and nimbler, and tend to be less disruptive to wildlife.
Treadmill and swim chamber
Researchers want to understand how much polar bears exert themselves while walking across the tundra or swimming through the Arctic Ocean. To get a handle on the marine mammals’ energy output on land, Anthony Pagano, a biologist with the United States Geological Survey, built a special heavy-duty polar bear treadmill. Study collaborators at the San Diego Zoo and the Oregon Zoo then trained captive polar bears to walk on it. Using shatterproof plastic and reinforced steel, the team constructed a 10-foot-long chamber that encased a treadmill typically used by horses. The 4,400-pound contraption also included a circular opening where researchers could tempt the bears into walking with fish and other tasty treats.
As a follow-up to the walking study, Pagano and biologists at the Oregon Zoo also measured the energy output of the bears while swimming. To do so, they developed a polar bear-sized swim chamber, complete with a small motor that generated waves to simulate the conditions the bears might encounter in the ocean.
Together, the two technologies helped scientists learn that bears expend more energy swimming than walking. Polar bears are good swimmers, but they’re not very efficient ones, thanks to their relatively short arms, their non-aerodynamic body shape and their propensity for swimming at the water’s surface, where drag is greatest. In a world with shrinking sea ice, polar bears likely need to swim more to find food and, thus, will burn precious calories, which could cause them to lose weight and lower their chances of reproducing—decreasing the species’ chances of survival.
Together, these and other technologies are helping researchers learn how polar bears are faring as the climate evolves. This knowledge, in turn, informs conservation decisions to help protect the bears and their environment—and the health of the planet more broadly.
“We need to understand more about how the Arctic ecosystem is changing and how polar bears are responding to loss of habitat if we are going to keep them in the wild,” says B.J. Kirschhoffer. “Ultimately, our fate is tied to the polar bear’s. Whatever actions we take to help polar bears keep their sea ice habitat intact are actions that will help humans protect our own future.”