Sperm whales can be seen year-round in the Azores, and have become the iconic species in this area. They also inhabit other deep oceans of the world, with the females and calves being restricted to warmer waters and the mature males ranging from the Arctic to the Antarctic.
The sperm whale is also known as the cachalot. The strange name “sperm whale” comes from the whaling times, when the whalers first examined the content of the whales’ large head they discovered a creamy yellowish-white substance which they thought resembled sperm. This is of course not the case as females also have this substance in their heads. This substance is a wax (called spermaceti) which is used in the sperm whale’s highly developed sound system (known as echolocation). The wax acts by focusing the whale’s clicking sounds which echo through the large head.
Sperm whales hold a few impressive records: they are the largest of the toothed whales and the largest toothed predators in the world, they have the largest head and brain in the world, and they produce the loudest sounds in the animal kingdom (their clicks have been recorded reaching levels up to 236 dB). Sperm whales are thought to have the longest gestation (up to 18 months) and they are the most sexually dimorphic of all cetaceans (females reach only 2/3 the length and 1/3 the weight of mature males) and they may be the deepest divers in the world (possibly diving to over 3,000 m deep, or 10,000 feet). Sperm whales feed mostly on various squid species, including the large giant and colossal squid.
The blow from a sperm whale is easy to identify out on the sea because the blowhole is located in the front of the head and to the left, giving an angled bushy blow. In the Azores, the very social family groups of around 12 individuals are seen regularly, especially in the warmer summer months. The only natural predator of the sperm whale is the orca, also known as the killer whale. When a sperm whale group is threatened, the females show a defensive behaviour by creating a ring around the calves, this is called a ‘Marguerite’, either with their powerful tails or heads capable of ramming facing outwards.
Male: 18 m
Female: 12 m
Calf: 4 – 5 m
Male: 57,000 kg (maximum recorded 68,000 kg)
Female: 20,000 kg
Calf: 1,000 kg
Global population: c.360,000 (population trend unknown)
Diet: Squid, fish (deepwater)
Teeth: 40 – 50 in the lower jaw (more common in males)
Longevity: 70 – 80 years
Breeding age: Unknown
Gestation: 18 months
Nursing: 2 – 12 years
In other languages:
Norwegian: Spermhvalen, kaskelott