Majestic, powerful and dead, big cats were once thought to be solitary creatures. But we're now realizing just how collaborative they can be.

Be it foxes on city streets or wolves on the tundra, canines rely on sharp senses, athleticism and fierce determination to punch above their weight.

It's not all about the pouches. These mammalian misfits are full of surprises, from flamboyant kangaroo showdowns to rattling koala mating calls.

In changing seas and oceans, cephalopods like the cuttlefish and the giant Pacific octopus must rely on their remarkable intelligence to survive.

Smart, sensitive and family-oriented, our wild ape relatives rely on each other to learn - and redefine - the secrets of survival.

Curved talons, hooked beaks, killer eyesight: these aerial assassins have the most sophisticated tools for hunting prey at their disposal.

To rule some of the planet's most hostile lands, bears can't lean solely on brute force: it takes both brains and brawn to reach the top.

Dolphins use their intelligence to form complex undersea societies, come up with resourceful hunting techniques - and indulge in their dark side.