Millions have seen the heart-wrenching video of a polar bear clinging to life, its white hair limply covering its thin, bony frame. Shot by Paul Nicklen and Cristina Mittermeier of the nonprofit group ...

During weeks on a research vessel drifting with an ice floe in the polar night, a photographer discovers profound beauty—and her own limitations. Polar bear guard Trude Hohle checks for a safe path ...