Sperm Whale
Sperm whales are the largest toothed whale. They do not filter-feed with baleen
as do blue whales, but instead chew and swallow their food, letting them eat larger prey.
The head of the sperm whale is huge, taking up 1/3 of its total body length. Its body is
wrinkled, and its blow hole points forwards instead of backwards. Sperm whales are best
known from the book Moby Dick, as the giant white whale that is being hunted
throughout the whole book.
Sperm whales reach lengths of up to 60 feet, and can weigh up to 45 tons. They
must eat quite a bit to get this size, over a ton per day. Their main source of food is the
deep water squid, but they also eat octopus, skates, and many species of fish. Large
suction marks on the sides of some sperm whales have made some scientists wonder if
sperm whales may have come into contact with giant squid, a little known species of
squid that can become more than 10 times larger than its smaller relatives.
Sperm whales live in all oceans of the world, the males tending to live farther
north than the females. They migrate farther south in the winter. The young and their
mothers stay in tropical waters all year round.
Sperm whales are the deepest diving of all whales, living as deep as 3,300 feet
and can stay underwater for over an hour. There is very little light that deep, so sperm
whales must rely solely on echolocation, making clicking noises to find their prey and to
avoid predators.
Selective killing of older males has disrupted the breeding cycle, but the
population of sperm whales is still rather numerous, numbering at a little over 500,000.
This is a good sign, since sperm whales are needed to regulate populations of squid and
certain species of fish.