dr. todd atwood and his team tranquilize the bears from helicopters, collecting samples. >> this looks like a male. >> reporter: stud yying how climate change is affecting these bears. >> helps with warmth and friction i think. traction. those beautiful claws. >> reporter: we spend about 45 to 50 minutes with each bear that we capture. we collect a variety of samples. a bunch of body measurements so we can measure physical stature and how physical stature might be changing through time. >> probably right on the cusp of being an adult. and we gave him seven ccs, which is a standard dosage for a bear of this size. >> i think the most surprising thing for me personally has been the complexity of their behaviors. we see them adapt to some pretty dramatic changes in the arctic sea ice ecosystem. we're seeing them use terrestrial habitats to an extent we didn't expect them to be able to use. we're seeing them switch to certain food items that we didn't expect them to switch to. we can characterize stress using hair samples, and we can relate that to how the environment has changed around polar be