Big Beasts

A four-ton elephant seal returns to his breeding beach on the cusp of summer—and quickly learns the competition for females is fierce.

Makumba is one of the best studied gorillas in the world. Now past his prime, he must find new ways to maintain his status as king of the jungle.

Rocky Mountain summers are fleeting, leading local bears to gain weight, sharpen defenses, and engage in a dynamic fight for domination.

In Borneo, apes and monkeys train their babies in the treetops, but with gravity against them, the stakes are high—and crocodiles lurk below.

Subzero temperatures force polar bears to bulk up—but as summer returns and the planet grows warmer, they find themselves on thin ice.