Two polar bears at the Oregon Zoo are helping researchers at the U.S. Geological Survey study how climate change is affecting wild polar bears in the Arctic.
As sea ice retreats, scientist know polar bear habitat is changing. But it’s hard for researchers to study how that affects polar bear behavior because the bears are so remote.
So scientists at USGS are using captive bears at the Oregon Zoo to learn more about Arctic polar bears.
In one study, a polar bear named Tasul has been trained to wear an accelerometer on a collar that measures her movements while she’s walking, eating, sleeping and swimming.
Anthony Pagano, a wildlife biologist with the USGS Alaska Science Center, videotapes the bear’s behavior while she’s wearing the collar so he can match those movements with the electronic signals in the accelerometer.
He’s also attached same kind of accelerometer to 10 wild polar bears in the Arctic.
“With climate change they’re now moving expansive distances far from the coast to follow the receding pack ice where nobody is able to observe them,” Pagano said. “We don’t have any data as to whether they’re able to forage over these habitats.”
With Tasul’s help, Pagano can match the digital signals from the collars on polar bears in the Arctic with the movements he’s recording at the Oregon Zoo.
That way he can study whether changes in the amount of pack ice available to wild polar bears is changing how much they walk, forage and feed.
“My project is looking at how much time are they able to spend foraging over these habitats as climate change is coming into effect, and what impact might that have on polar bears energetically,” Pagano said.
Tasul and another polar bear at the zoo named Conrad are also helping with another climate change study that is developing a new method of measuring polar bear diet through blood and hair samples.
Karyn Rode, research wildlife biologist with the USGS in Alaska, wants to know whether retreating sea ice is affecting what wild polar bears eat. She thinks a loss of sea ice could restrict their access to the ice seals, and that could affect their health and ability to reproduce.
“Currently we have limited tools to know what polar bears in the wild are eating and how much their eating,” she said. “If this new technique works, we’ll be able to look back at 30 years of hair and blood samples we’ve collected and determine what the diets of those bears were and how it might have changed with changing sea ice conditions.”
Amy Cutting, animal curator at the Oregon Zoo, said Tasul and Conrad are both quite old for polar bears at age 27, and they’re both so well-trained that they voluntarily offer their feet to zookeepers collecting blood and hair samples. She said the zoo wants to use its access to trained polar bears to help researchers develop new methods of researching the impacts of climate change.
“In the wild, polar bears are notoriously difficult to get to, to monitor and observe in any way,” Cutting said. “We have access to polar bears every day, and we’ve always wanted these polar bears to be ambassadors for their wild counterparts.”