Extras
Uncover the secret world of New York and London’s resilient pigeon flocks.
Who rules the streets -- and skies -- of the city?
Follow a female mountain lion in the Montana mountains over the course of a decade.
Mountain lions risk everything to hunt elk, prey more than twice their size.
A mother mountain lion risks her life to feed her six kittens.
It was once believed that walruses dug for clams with their tusks, but the truth is even stranger.
Discover how rapidly declining sea ice is reshaping the future for walruses.
An orphaned baby walrus, just a week old, gets a second chance.
See how the Arctic’s most enigmatic animals are coping as the sea ice melts.