The Amazon, the largest rainforest on Earth; drone footage captures giant otters hunting together while black caimans prey on newly hatched turtles; a harpy eagle chick's first days in the canopy and army ants on the move reveal new behaviors.

The Frozen North, where wolves and polar bears vie for food, hares outsmart lynx and walrus sing on rocky shores. As summer arrives, grouse perform mating dances, caribou migrate vast distances and salmon race upstream to survive.