Spotting a polar bear from a helicopter against the frozen tundra can be difficult. When polar bear biologist Jon Aars sets out for his annual research expeditions, he scans the landscape for sparks of movement or subtle color variations—the slightly yellowish hue of bears’ fur that appears on the white snow.
Dr. “Also, you usually see footprints before you see the bear,” Aars said. “And the bear is usually where the footprints stop.”
Dr. Aars is a longtime polar bear researcher at the Norwegian Polar Institute, which has an outpost in Svalbard, an Arctic archipelago. Since 1987, the institute’s scientists have held annual field trips to the icy wilderness of Svalbard to find and study polar bears.
For decades, these research trips have shed light on the basic biology and ecology of bears, and in recent years have helped scientists track how animals cope with climate change. Rapid habitat changes are already affecting their behavior; As the sea ice is rapidly retreating, some bears now have to swim long distances to find a place to land. However, Dr. So far, the bears themselves still seem intact, Aars said.
But if that starts to change, as researchers worry, these annual field trips will help uncover problems early on.
Here’s how scientists got them out.
The excursions are usually held in the spring, when female bears have emerged from their den with their new cubs and the sea ice is firm enough to support potentially dangerous research. Scientists cross the archipelago by helicopter to maximize the study area and the probability of finding the moon. Dr. “And of course, if you have a helicopter and you land on the ice and it’s thin, you run the risk of crashing the helicopter,” Aars said.
Once airborne, the team, typically consisting of two biologists, a veterinarian, a helicopter pilot, and a mechanic, begins scanning the terrain for bears. When researchers spot one, they aim a calming arrow from the air. If they do reach their destination, it usually only takes a few minutes for the bear to lay flat on the ice.
Then the researchers get down and get to work. Dr. They wrap a piece of cloth around the bear’s eyes to shield the bear from the sun’s fierce rays—a scarf or blanket works,’ Aars said, and they set up equipment to monitor the bear’s heart rate, blood oxygen levels, and body temperature.
They take various physical measurements that count the animal’s length, circumference, and skull size. They also examine his teeth, which can provide a good estimate of his age.
Dr. “When you do that with hundreds of bears, you know, you start to get pretty good at it,” Aars said. Female bears are also weighed, a delicate maneuver that requires being lifted into the air on a stretcher attached to two spring scales. (Male bears are too heavy to weigh.)
They then take blood, fur, and fat samples and put the blood sample in a pocket to keep it from freezing. Dr. “Just put it inside your jacket, close to your body,” Aars said. Back in the lab, these samples will help scientists answer any questions about the animal’s life: What does it eat? (Sometimes a bear is covered in blood when researchers find it, a sign that it’s been making a seal meal.) Does it have parasites? Has it been exposed to too many pollutants? They can also extract DNA from these samples to learn more about the genetics of the local polar bear population and to draft ursin family trees.
Some female bears are given satellite collars that track their location and activity. When the bears fall into the water, a “saltwater switch” on the collar activates, allowing researchers to calculate the amount of time the bears spend swimming.
Before finishing, the researchers gave the bears a few identifying marks by attaching an ear tag, implanting a microchip behind the ear, and beating a number inside the lip. But they also add a more temporary mark by drawing a number on each bear’s back. The number that will be lost when the bear sheds its feathers prevents scientists from catching the same bear in the same field season. Dr. “We don’t want to deal with that bear twice,” Aars said.
The whole process takes about an hour for a single bear and longer for a female with cubs. When the researchers are done, the vet prescribes a drug to help reverse the sedative.
Sometimes researchers wait for the bear to arrive to make sure it can stand up and walk safely. They keep their distance, but Dr. For Aars, work has become routine and he is not afraid of bears when he wakes up. “It’s not like the bear said, ‘Okay, I want to kill that guy,'” he said. “I think it’s more like seeing if you’re okay and possibly having a little headache and thinking about other things.”
And then they’re in the air again, looking for their next bear.
Anna Filipova He is an Arctic photojournalist specializing in scientific issues covering the polar regions for 10 years.