YOUNG: ItÂ’s Living on Earth. IÂ’m Jeff Young.

CURWOOD: And IÂ’m Steve Curwood. Just ahead, a sad phenomenon in the Pacific Northwest, but first this note on emerging science from Lisa Song.

SONG: As climate change thaws the Arctic, itÂ’s more important than ever to keep an eye on polar bears. Scientists are now turning to Inuit expertise to monitor bear populations. For Inuit hunters, a single paw print can reveal a polar bear's sex, age, and size. The expert trackers will help researchers study polar bear movements and the accuracy of those skills will be tested by Canadian scientists.

At the same time, scientists will build fences around pieces of meat used as bait. As polar bears dine on the meat, bits of fur will get trapped on the fence, and biologists can use DNA markers from the hair to identify individual bears. Bear droppings will also be collected to study for signs of disease.

Currently, researchers follow bears in helicopters and inject them with tranquilizers before tagging the animals for study. The new system is cheaper and more humane. It also helps economic development. The Inuit hunters will work from cabins in the far north, close to Baffin Island. When not being used for research, the cabins can be rented by eco-tourists.

Scientists hope that this combination of traditional skills and DNA technology will be used to create a map of polar bear behavior and migration - a census of the great carnivores in a world of warming ice. ThatÂ’s this weekÂ’s Note on Emerging Science. IÂ’m Lisa Song.