White bears on an island of British Columbia learn survival by trial and error.

Five scientists who learned that keystone species can make or break the ecosystems they live in recall stories of their adventures in the wilderness in the 1960s.

This long-running, award-winning documentary series focuses on science, its many applications, speculation, history and researchers. Inspired by the BBC documentary program "Horizons, " the U.S. series frequently features interviews with scientists directly involved in the topic at hand, and sometimes even boasts footage of a particular discovery.

Uncovering how similar humans really are to animals using a new generation of spy cameras.

This award-winning series presents compelling untold stories and covers a wide array of provocative subjects. "Explorer" aired for 25 years -- the longest-running documentary series in cable TV history -- before being relaunched in 2015 after a five-year hiatus. Each monthly episode of the new "Explorer" takes a similar deep dive inside a story from the pages of a recent National Geographic magazine issue, taking viewers not only to the most remote corners of the globe but also to the furthest reaches of the mind and deepest crevices of history -- on urgent missions of discovery.

The planet is teeming with myriad life forms, both plant and animal, all interlocked in a struggle for survival. As time goes on, some living things are forced to adapt and change to survive. This series chronicles some of the most unusual, if not downright bizarre, behaviors that living organisms have devised to keep their species alive. The 11-episode series was four years in the making, taking camera crews to every continent and habitat.