Sperm whales are the largest toothed whales on the planet, and perhaps the most abundant of the great whales, but we rarely get to study them because they spend so much time underwater. Sperm whales are deep divers, holding their breath and diving thousands of feet down to feed on deep sea giant squid and fish. They spend 90% of their lives down deep where they can’t be seen. Only rarely do these energetic animals take a break and rest at the surface. Down in the depths, where there is no light, Sperm whales hunt using echolocation. The whale produces a series of loud clicks which travel through the water and bounce off objects. The reflected sound bounces back to the whale, which interprets the echo. Using this technique, Sperm whales can “see” in complete darkness. Sperm whales can most likely determine the size, direction and distance of prey, which helps them hunt deep below where there is no light.
The Sperm whale gets its name from the spermaceti organ which fills most of its huge head. Nobody is absolutely sure what the spermaceti organ actually does for the whale, but there are two prevalent theories. One suggests that the organ is a buoyancy control device. The other theory suggests that the organ is used to focus and control the beam of sound that the whale uses for echolocation. For all we know, both theories could be right.
Because of an uncanny ability to efficiently store oxygen in their blood and muscles, adult Sperm whales can stay submerged well over an hour without taking a breath! They have been tracked by sonar diving to depths of 3,900 feet. However, one Sperm whale caught by a whaling ship in water 10,000 feet deep had a bottom-dwelling shark in its stomach, leading researchers to believe that the Sperm whale can dive a lot deeper than seems possible. Just as amazing is how fast they whales may reach that depth. In one study, a Sperm whale descended at an astonishing 550 feet per minute!
The Sperm whale probably has one of the most stable populations of any whale on Earth, possibly more than a million. This means that the Sperm whale is the only great whale species which is not endangered. Kalpitiya, Mirissa & Trincomalee are the best locations to observe this fascinating ocean giant.