Sperm Whale (Physeter macrocephalus)


Formerly known as Physeter catodon, the Sperm whale is the largest of the toothed whales (Odontoceti). Males reach 50 to 60 feet (15 to 18 m) and weigh 48 tons (43 m tones), while females grow to 15-38 feet (4.6 to 11.6 m).  This species is very distinctive looking, with a massive bluntly square head which can be one third the length of its body. This whale has a long, narrow lower jaw which contains 36-40 teeth, while the top jaw contains sockets into which the lower teeth fit.

Toothed whales have a single nostril, unlike baleen whales which have two. In the Sperm whale the nostril is on the left side of the front of the head. When the whale blows the 15 foot (4.5m) spout is projected forward and to the left.

The body colour of the Sperm whale is dark grey or brown and the skin on the back half of the whale towards the tail is wrinkled. Sperm whales have a short rounded dorsal fin and flippers. The dorsal fin is a low hump followed by a series of bumps along the back. The fluke is roundly triangular with a deep central notch, rounded tips and smooth, straight edges. Like the Humpback, the Sperm whale raises its fluke out of the water when it makes a deep dive.

The Sperm whale has a wide global distribution. They migrate seasonally in search of food. Sperm whales primarily eat squid, but will eat fish. They hunt in darkness at depths over 1000 feet, so they produce loud sonar clicks to find food and communicate with each other. The huge head of the Sperm whale contains a store of waxy liquid called spermaceti which is thought to help with this kind of echo location behaviour.

In the 18th and 19th century spermaceti was used to produce candles and other products and was considered extremely valuable. The oil produced from boiling the fat (blubber) of Sperm whales was burned for heat and light and was used to make lubricants for machinery and soap. Sperm whales were widely hunted to obtain these valuable products, leading to a world-wide decline in their population.

The large intestine of a Sperm whale may also contain ambergris. This substance was historically used to make perfume and cosmetics; it was rare and therefore very expensive. This important whale product played an important role in the earliest Bermuda economy. The Somers Isles Company in London sent strict instructions to Bermuda’s first Governor Daniel Tucker in 1616 on how to deal with any ambergris from captured whales or found upon the shore. Large rewards were paid to anyone who turned over their ambergris, and harsh penalties where laid out for anyone found withholding it.

Today in Bermuda Sperm whales are not as frequently encountered as Humpbacks.  They prefer deep water thousands of feet deep. They are occasionally seen around Bermuda by boaters offshore and yachts passing between Bermuda, the Caribbean and North America (see Newport video). On several occasions Sperm whales have stranded in Bermuda. This either means a dead whale has washed ashore (e.g. the baby found off Somerset in 2010) or an ill, injured or confused whale has come inshore.

Due to their historic decline from whaling and other more modern threats like ship strikes, entanglement in fishing gear, pollution and man-made noise in the ocean, Sperm whales are considered globally Vulnerable. In 2011, the Sperm whale was listed as a Level 1 protected species under the Bermuda Protected Species Amendment Act. This makes it an offense for anyone to disturb a Sperm whale in Bermuda’s waters.

A baby sperm whale learns to swim alone while its mother hunts deep below. See All National Geographic Videos