Voices of the Sea

S1 E3: Taking a look at whales and dolphins, nature's supreme vocalists. The mighty sperm whale creates deafening clicks to hunt giant squid in the ocean abyss, while narwhals use sound to locate vital breathing holes in Arctic ice-floes. The Amazon boto dolphin's ultrasonic calls help it find fish in murky waters, while killer whales in the North Sea use wolf-like howls to round up herring shoals.