RENEE MONTAGNE, host:
Back on Earth, the polar bear has become a symbol for the potentially devastating effects of global warming. The animal depends on sea ice for its survival, and that ice is disappearing, especially in the Chukchi Sea - a remote stretch of water between Alaska and Russia.
U.S. biologists don't know much about the bears that live there, and they're trying to learn as much as they can before the bears' habitat melts away. Alaska Public Radio Networks' Annie Feidt went along with one biologist for a day of field work and has this story.
ANNE FEIDT: It's not every day you find yourself holding a microphone an inch from a polar bear's snout.
(Soundbite of polar bear breathing)
FEIDT: Lucky for me, this bear is sedated, resting on a slushy bed of ice. We're 100 miles from land in the middle of the Chukchi Sea. Round sheets of ice are broken up occasionally by a strip of inky blue water. To my eye, it is a starkly barren landscape. But to this polar bear, it's a rich environment he's brilliantly adapted to. Eric Regehr is the biologist with the U.S. Fish and Wildlife Service. He crouches down next to the bear to show me one of its paws.
Mr. ERIC REGEHR (Biologist, U.S. Fish and Wildlife Service): You see they have very sharp hooked claws like that for gripping on the ice and also for gripping onto their seal prey. You can feel how sharp these are.
FEIDT: This is a relatively small bear. Regehr guesses he is about four years old - an adolescent.
Mr. REGEHR: He has a pretty big feet, like a puppy, you know, big feet they have to grow into.
FEIDT: While the bear sleeps, Regehr learns as much as he can about him. He takes blood, hair and fat samples and he measures his length and weight. This bear is about seven feet tip to tail, and nearly 700 pounds - tiny compared to many full-grown males. And Regehr has weighed a lot of huge bears this year. One even set a springtime record in Alaska at 1,266 pounds.
Mr. REGEHR: He was borderline obese. He was a very fat bear for this time of the year. If you look at him in profile, his belly almost scraped the ground, so he was a really fat, good-looking bear. And in general, most of the bears have appeared quite healthy.
FEIDT: The bears may be in good shape now, but the ice that allows them to gorge on blubbery seals is retreating at an alarming rate. Regehr says the future for Alaska's polar bears is grim, and he's already seeing one potentially troubling sign: very few females with cubs. The bear Regehr is studying today is the 39th he's examined this season. His last step is to draw that number with fur dye on the polar bear's back.
Mr. REGEHR: Because of the long wet hair, it's little harder to paint.
(Soundbite of brushing polar bear with paint brush)
FEIDT: Each bear is also outfitted with ear tags and a lip tattoo that will allow Regehr to track its progress if he captures it again next year. It will take several seasons of study to understand how the polar bears in this region are reacting to their changing environment. Rosa Meehan heads the Marine Mammal Division of the U.S. Fish and Wildlife Service in Anchorage. She says the knowledge will make it easier to help the bears through difficult times ahead.
Dr. ROSA MEEHAN (Marine Mammal Division, U.S. Fish and Wildlife Service in Anchorage): The thing that I focus on is the need to give bears as much of a break as we can during this impending climate crisis, in the hopes that we can get our hands on climate change and address it in a realistic fashion. If we can do that, then there's hope that the environment will stabilize, will come back and that we'll still have bears there to come back and repopulate.
FEIDT: Meehan says one idea is to set up land refuges where polar bears may be able to eek out a meager existence for a while. But, she says, that's a frightening possibility to consider for a species meant to live on the sea.
For NPR News, I'm Annie Feidt.
MONTAGNE: Now, for a quick update: American journalist Roxana Saberi has been released from prison in Iran. She was convicted last month of espionage and sentenced to eight years. Today, an Iranian court reduced that sentence and commuted it. Her father met her at the prison. He told reporters that she's in good condition. We'll continue to bring you news in this story as we learn more. You can also follow developments at our Web site: npr.org.