Polar bears aren't the only beloved Arctic animal threatened by climate change. Scientists believe reindeer are at risk as a warming world makes their main winter food source disappear.
But reindeer on one Alaskan island are surprising researchers.
And that surprise doesn't just come from the fact that the reindeer are hard to spot.
On St. Paul Island, Lauren Divine of the EcoSystem Conservation Office was not having luck seeing a herd of 400 reindeer, even on this treeless island with tundra as far as the eye can see.