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

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.

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

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