Even after half a lifetime studying polar bears in some of Earth's least hospitable climates, Andrew Derocher still gets nervous trying to tag a 1,000-pound bear on a frozen slab of ice in the open water.

"[The bears] are not worried about being out there, but it’s just not good enough for us," he says.

Photo by Andrew Derocher.

Keep Reading Show less
Heroes

Polar bears are largely known as the poster-pets of environmentalism, and it's easy to see why.

They're like giant, adorable, white-but-not-actually-white teddy bears who could just as easily cuddle you as kill you.

Also they've spent the last half-century dwindling near extinction and are still considered threatened under the Endangered Species Act.

Keep Reading Show less
Heroes