Known as: Sperm Whale, Cachelot.
Estimated numbers left in the wild: At least 200,000; perhaps as many as 1 million.
Description: A dramatic-looking beast with a cliff-like snout and a massive, streamlined body, the sperm whale is one of the world’s most imposing creatures. Large males are 20 meters long, though the average is 16 meters. These whales can weigh up to 57,000 kilograms, their weight supported by the ocean’s waters. The sperm whale’s head is around a third of its length, including a massive internal chamber full of an oil called spermaceti, and a brain five times the size of a human’s – weighing in at 7.8 kilograms – though its structure is much less advanced.
Sperm whales are social creatures and often gather in pods of up to twenty animals, mostly females and calves. Males are solitary, or temporarily associate with a pod before moving on. Living in a pod allows females to better protect their calves from orca attacks. Once sperm whales reach maturity, there are no predators except man capable of killing them, and their lifespan in the wild is approximately 70 years. Calves are born every three to six years and can take 10 years to mature.
Sperm whales are capable of dramatic dives after their prey, able to reach depths of 1,000 meters and often staying underwater for up to 90 minutes before surfacing for air. They are toothed whales who consume around 900 kilograms of fish and squid every day. It is believed that they hunt giant squid deep in the sea, and some sperm whales have been observed with sucker scars left by desperate undersea battles with this tentacled quarry. Sperm whales make a clanging sound for echolocation, and it is likely that the huge reservoir of spermaceti oil is used in the operation of this natural sonar system. Whalers took sperm whales for this oil for centuries – some believe that sperm whale size has decreased due to over-hunting, while others believe it has risen due to less competition for food resources after the population was culled by humans.
Location: Sperm whales are found everywhere throughout the world’s oceans, with the exception of the Arctic ocean and some parts of the Antarctic. Only large males venture into the colder waters of the extreme north and south. Sperm whales are a deep water species and seldom come inshore. Sperm whales are absent from the Red Sea and Black Sea.
Threats: Sperm whale populations were devastated between the mid 19th and mid 20th centuries due to intensive whaling, assisted by improved whaling technologies. Roughly a million whales were taken during this century-long period. Prior to that, whaling occurred, but the catch was greatly limited by less advanced technology. Today, commercial whaling is no longer a threat, though the Japanese continue to harvest a number of whales by claiming that these are needed for scientific purposes, though their meat ends up on supermarket shelves in Japan. The chief threats to sperm whales today are collisions with ships (often injurious or fatal) and becoming caught in fishing nets. Some fatalities are also caused by pollution and by eating marine debris.
Conservation efforts: Sperm whales are fully protected by international law and are, in fact, their numbers are increasing despite current hazards. Many environmental groups and governments are involved in creating a safer environment for these huge mammals, including efforts to ensure migration routes are clear of obstacles such as large fishing nets.
Sperm Whale Videos
The Hebridean Whale & Dolphin Trust monitors marine mammals and their habitats off the coast of Scotland. They work to protect various species through outreach and educational programmes.