In the rugged terrain where Mexico and the United States meet, a border wall is just the latest obstacle fragmenting habitats and disrupting migration paths. Here’s how a cadre of conservationists is ...

A deep and exclusive look inside National Geographic's ambitious Secrets of the Penguins with host Bertie Gregory.

While some animals (and humans) hibernate in winter, other species are at their most active. Whales, butterflies, and birds are migrating; elephant seals are mating; and wolves are actively hunting ...