When Nora the polar bear returned to the Oregon Zoo earlier this month, in many ways she came back the same bear as when she left more than three years ago.
She still thrived in close proximity to humans, paying special attention to her keepers. She still had a bow-legged stance in her front legs, the remnants of skeletal issues she suffered as a cub. And she still has her signature move: grabbing the head of a bristle brush and flinging it over her head into the pool before executing a back dive to retrieve it.
But Nora is also a very different bear than the nearly 2-year-old bear she was when her first stay in Portland ended in 2017. She’s older, obviously, and bigger, now weighing around 500 pounds. But she’s also more patient, having learned the ways of her species from another bear over the last few years. She now has a metal rod in one of her legs after a broken bone and a first-of-its-kind surgery.
While circumstances for Nora have improved since she departed the Oregon Zoo for Salt Lake City in 2017, the same cannot be said for her species. Warming in the Arctic, caused by climate change, has continued to put their future in jeopardy, eating away at the sea ice polar bears depend on to survive.
And that’s where perhaps the biggest difference lies for Nora. Many zoos have transformed over the past half century from entertainment attractions to centers for education and science, and the Oregon zoo is no different. As she returns to the zoo where she spent a fair amount of her formative years as a cub, she comes back to a completely revamped exhibit, one created to put conservation science at the forefront for zoo goers, meant to reinforce the connections between captive animals like Nora, her wild counterparts and the people who can once again come to see her.
“We really wanted to focus on increasing scientific literacy,” said Amy Cutting, a curator at the zoo who oversees the Polar Passage exhibit.
A rough start
Nora’s life has been marked by struggle since her earliest days. In late 2015, she was abandoned by her mom less than a week after she was born in Columbus, Ohio, and then raised by a team of zookeepers. She developed metabolic bone disease after she failed to absorb some vital nutrients as an infant, which would lead to skeletal issues later on.
When she was around 10 months old, Nora’s mom was pregnant again and the zoo in Ohio needed to make room for the new cubs. Nora also needed the company of another bear to learn all the things her keepers couldn’t teach her, so she was moved to the Oregon Zoo and paired with Tasul, an older bear that the zoo hoped could act as a mentor.
But soon after she moved to Oregon, Nora developed anxiety and needed medications to help her cope. She and Tasul never got along as well as zoo staff hoped, and the older bear died within a few months of Nora’s arrival.
A short time later, keepers noticed Nora had a bit of an odd gait and, after veterinarians examined her, they realized her bone issues as an infant had left her with some deformations in her joints. Her elbows bowed out when she walked, in what keepers called a “bulldog stance,” and she would likely have early-onset arthritis.
Still, her keepers’ biggest worry was that she had spent little time with any other bears. With construction on Polar Passage looming, Nora was moved again. This time to Utah’s Hogle Zoo in Salt Lake City, where she would be paired up with another bear named Hope.
Many of Nora’s struggles were chronicled in a five-part series from The Oregonian/OregonLive in 2017.
After some initial trepidation, Nora and Hope became close companions, playfully wrestling, chasing each other and even sharing toys. Having spent so much time with people, the relationship was an important step in Nora’s development. Her keepers were overjoyed.
Then, one morning in January 2019, the keepers found Nora unable to move. She was eventually able to maneuver herself back to one of the dens, and veterinarians performed X-rays. She had broken her humerus, a large weight-bearing bone in one of her front legs. A surgical team was brought in from Texas A&M University and, after a nearly eight-hour procedure, a metal rod was inserted inside the broken bone.
She went through months of physical therapy, separated from Hope, but eventually made a full recovery. Zoo officials never figured out how Nora suffered the injury, but they ruled out her early skeletal issues as a cause.
New home, old home
In January of this year, the Utah zoo announced that Hope would be moving to another zoo in the hopes she would breed. With an older male bear set to move into the Salt Lake City enclosure, it was decided that Nora would be moving yet again, but to familiar environs. Nora would be coming back to Portland.
In early March, Cutting made the trip to Utah, met with Nora’s keepers there and watched as she was carefully loaded into a travel crate, which was then loaded into a trailer for the nearly 12-hour drive.
Nora was given some light sedatives and Cutting said the transport team stopped every hour to make sure she was faring well. The drive went without a hitch and Nora was met by a team of keepers, many of whom had cared for her years prior. One of those keepers, Nicole Nicassio-Hiskey, was there to meet Nora soon after she arrived.
“Seeing Nora this morning was so exciting,” Nicassio-Hiskey said at the time. “She has grown into a beautiful bear. Her coat looks great and she seems very comfortable already.”
Some of Nora’s early setbacks will have lasting impacts, Cutting said. She still has the odd gait and keepers will have to make sure she doesn’t gain too much weight to ease the strain on her malformed joints. She still takes a low-dose antidepressant, Cutting said, but most of the troubling behaviors—pacing and tantrums triggered by anxiety—they saw when her mental issues were at their worst have ceased.
A species under threat
As Nora moved from zoo to zoo and overcame her various struggles, her wild counterparts were not faring so well. Polar bears in the Arctic rely on sea ice to hunt seals, which make up the vast majority of their diet. Seals and other marine mammals are the only prey that offer enough calories for polar bears to survive in the far north and, without ice, they are left to forage for foods that cannot meet their needs.
The Arctic is warming twice as fast as the rest of the planet, and sea ice has been trending smaller since at least the early 1990s. Every year, sea ice grows and shrinks with the seasons. It usually reaches its smallest size in September, a measurement scientists call the Arctic sea ice minimum. That number has been declining by more than 13 percent per decade, relative to the average between 1981 and 2010, according to NASA.
The polar bear population is not a monolith. The estimated 26,000 bears that roam the Arctic are divided into 19 subpopulations, and some are faring worse than others. The most recent estimates, compiled by the International Union for the Conservation of Nature, show that four of the subpopulations have seen declines in recent years, but five of them are likely stable and two of them likely saw their numbers grow over the last couple decades. There wasn’t enough data to form estimates for eight of the groups.
But over the long term, the prognosis for polar bears is bleak. In 2020, a group of researchers found that if carbon dioxide emissions stay on their current trajectory, many subpopulations could begin to see reproductive failure by the 2040s. By the end of the century, the researchers said, most subpopulations would be functionally extinct with only a small group remaining in Canada’s Arctic Archipelago.
Bridging the gap
Studying wild polar bears is a tremendously challenging endeavor, so some wildlife biologists have turned to zoo bears as research subjects. The Oregon Zoo has been on the leading edge of those efforts.
After years of training and building trust with Nicassio-Hiskey and other keepers, Tasul became the first captive bear to voluntarily submit to a blood draw without the use of tranquilizers in 2011. The zoo hosted U.S. Geological Survey scientists who outfitted her with a research collar that measured her movements. The old polar exhibit was home to a one-of-its-kind swim flume, essentially a sealed chamber that researchers could use to measure a bear’s oxygen intake while in the water. Most of that research happened behind the scenes, though.
In the new Polar Passage, conservation science will be front and center. In an area the zoo is calling the Arctic Science Center, keepers will now do those training exercises in full view of zoo visitors under a memorial to Tasul and her brother Conrad.