Treading water outside the glass wall of the Polar Bear Odyssey pool at the St. Paul Como Zoo, Kulu looked like he was performing a flirtatious dance for visitors — sociably waving all four legs, white fur gently swaying, always staying inches from the window while children leaned close, eyes wide with awe.

From all appearances, Kulu was enjoying the interaction as much as the kids were.

Kulu, who turns 2 this month, is still an exuberant youth himself. He recently arrived at his new home from the Columbus (Ohio) Zoo and Aquarium, where he was born. He joins Como's longtime polar-bear residents, Nan and Neil, who are 25 and 26, respectively (which is old for polar bears).

At over 700 pounds, Kulu already looks big, but will gain at least a few hundred more pounds by the time he's full grown, said Allison Jungheim, senior zookeeper at Como and a coordinator for the Polar Bear Species Survival Plan, an advisory group for the Association of Zoos and Aquariums.

Young though he is, Kulu is already performing services that may someday help his distant relatives — distant in both senses of the word — for the relatives he's helping are wild polar bears living in the Arctic, primarily in Canada, but also in Alaska, Russia, Greenland and Norway.

One of Kulu's important jobs is testing a new radio tracking device that may help scientists keep a better eye on polar bears as their populations decline due to global climate change.

Polar bears are particularly hard to track in the wild because of their harsh, remote and rugged habitat. Traditionally, tracking devices have been held in unwieldy plastic collars that could be placed only on female bears; young polar bears would quickly outgrow the collars, and they would slide off males because their necks are wider than their heads.

Newer trackers are an improvement. Unlike their cumbersome predecessors, they're smaller than a "fun size" Halloween candy bar which allows them to be, theoretically, attached to a bear's long fur. But that requires a tag that would stay in place in the rugged conditions to which a polar bear would subject it — lumbering through the dense brush that covers much of their onshore habitat, rolling around in the snow, roughhousing with other bears.

To the rescue came a volunteer group of 3M scientists called the Tech Forum.

Jon Kirschhoffer, a 3M researcher and product developer for 40 years before retiring in December 2020, belonged to the Tech Forum. Kirschhoffer — who, appropriately enough, lives in White Bear Lake — turned to the group after getting a request from his son, Jon "BJ" Kirschhoffer, who works with Polar Bears International.

"He reached out to me one day," said the elder Kirschhoffer. "He said, 'So Dad, we have a program where we want to stick a radio tag onto a bear. You work for a company that makes things stick. Would you be able to help us?' "

(Among other things, 3M manufactures Post-it notes as well as the hook and loop fasteners widely known as "Velcro" after a version made by a different company.) Kirschhoffer presented his group with the "Tag a Bear Challenge."

"We livestreamed polar bear experts and the scientific community to provide background on the nature of the problem," he said. "We got a list of the kinds of things the bears might challenge us with, the kinds of things they might do with the devices."

In the thick of it

The Tech Forum settled on four different prototype tags that cling to the bears' fur and can be used on males and younger bears, as well as females. The one Kulu wears on his back is called the "tri-brush attachment," a plastic triangle with metal spirals around its edges. Small brushes inserted into the spirals entangle the bear's coarse fur in the gadget. Other models, being tested on bears in zoos around the country and on 12 bears in the wild, use other methods of ensnaring themselves in the fur.

"In zoos, if it falls off, they can know why," said Geoff York, senior director of conservation at Polar Bears International. "Being able to tag and track bears of any age or gender will be a game changer. All this historical data we have is from females."

And if the tags work on polar bears, they could also be used to track other species, York said. "A great big bear is a pretty good test."

An estimated 20,000 to 26,000 wild polar bears currently live in countries around the world, York said. They're considered a vulnerable species because of how climate change is affecting their sea-ice habitat. Their numbers are declining, especially among those living in the areas farthest south, where some populations have dropped by 30-40%, York said.

The bears spend much of every year on the sea ice, hunting, eating — seals and walruses are their prey — and mating. The ice has been freezing later and melting earlier, shortening the time they can spend there.

"It's pretty dire with the lack of sea ice — polar bears are having a very tough time," Jungheim said.

Polar bears "are spending almost a month longer onshore than they have historically," said York, who spoke by phone from Churchill, Canada, near a bear habitat.

"We're seeing climate impact sooner and faster than expected on a number of fronts," York said. "It's raining here, at the end of October. It shouldn't be raining here at the end of October."

The shorter ice season can lower birthrates because female bears need to eat enough food while on the ice to sustain themselves through pregnancy later onshore, Jungheim said. If they don't gain enough weight, they have fewer cubs. In the 1970s and 1980s, bears often had three cubs at a time, rarely just one. Now, she said, it's the other way around.

Raising awareness

Without action on climate change, all but a few polar bear populations could disappear by the end of the century, the Polar Bear Institute warns.

That's where Kulu's other role comes in. By letting people see animals they'd never otherwise see, zoos and aquariums help raise awareness of how climate change and other environmental issues affect the world's wildlife, York and Jungheim said. Ideally, seeing a real polar bear up close and personal makes people more invested — and more willing to invest — in helping save them.

"We're very aware that most of the world will never have the opportunity to see a polar bear or other iconic species," York said. "Connecting people through zoos and aquariums can be a very powerful way of connecting people to nature."

So when a small boy at Como, held in his father's arms, pressed his hands against the window in the polar bear exhibit, transfixed by the sight of the huge white animal right outside the glass, Kulu was doing an important job.

But Kulu, dancing merrily, didn't seem to know he was working.