And far out to sea the largest brains on earth, fix on these mysterious cues. The male sperm whale, a creature of superlatives. It is the largest toothed predator alive today, weighing up to 50 tons. It dives deeper and faster than any other whale and it undertakes some of the greatest journeys. In a lifetime, this whale may log a million nautical miles. The males often circle the Arctic to feast. But for the species to survive, their paths must intersect with the females' own astounding journeys, coursing warmer waters. Many will meet in the Azores--nine tiny islands where clashing currents create an explosion of life.

 

A mother ushers her newborn calf into coastal waters, guided by sun, sea currents and perhaps even magnetic sensors in her brain. She also navigates by sonar, bouncing her clicks and creaks off the sea floor, some of the loudest sounds made by any creature on earth.