Sowerby's beaked whale

Sowerby's beaked whale (Mesoplodon bidens), also called the North Atlantic or North Sea beaked whale, is a type of toothed whale. It was the first mesoplodont whale that scientists described. An English naturalist and artist named James Sowerby wrote about this whale in 1804. He studied a skull from a male whale that got stuck on the shore in the Moray Firth, Scotland, back in 1800. He called the whale bidens because it had two special teeth in its jaw, a feature that is common in these kinds of whales.

Physical description

Sowerby's beaked whale has a typical body shape for its kind. The males have special teeth far back in their mouths. The whale's beak is of medium length, and the part above the nose is slightly rounded.

The whale is mostly grey with lighter coloring on its belly. It can reach about 5 meters (16 feet) for females and 5.5 meters (18 feet) for males, weighing between 1,000 and 1,300 kilograms (2,200 and 2,900 pounds).

Population and distribution

Sowerby's beaked whale lives in the North Atlantic Ocean, from Nantucket to Labrador in the west and from Madeira to the Norwegian Sea in the east. These whales are usually found in deep waters, between 200 and 1,500 meters deep.

There are no exact counts of how many of these whales exist. In 1991, about 90 sightings were recorded, mostly near the British Isles. Sometimes, these whales are found far from their usual homes. For example, one was saved after being found in Turkey in 2009. Sadly, some have also been found unwell or unable to return to deeper waters after being near places like Massachusetts, the UK, and Ireland. Scientists work to understand why these whales sometimes end up in places they don’t normally go.

Behaviour

Sowerby's beaked whales are shy animals that usually stay away from ships and are hard to spot. Sometimes, they are seen in small groups of up to 10 whales, including males, females, and young calves.

These whales likely mate in late winter and spring. After about 12 months of pregnancy, they give birth to calves that are about 2.1 to 2.7 metres long and weigh around 185 kilograms.

They eat small fish and a few types of squid, using a special way of feeding that creates suction to pull their food in. Sowerby's beaked whales dive very deep, often more than 500 metres, and sometimes even deeper than 1,000 metres to find food. Their diving style is more like that of Risso's dolphins and pilot whales than other similar whales. Their dives usually last between 30 and 40 minutes, and after diving, they swim quickly just below the water's surface before diving again.

Conservation

Sowerby's beaked whale has rarely been hunted by Norwegians, and those practices have stopped. Some whales die when they get caught in fishing gear, but this is not likely to harm the species much. This whale is protected by agreements such as the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS) and the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS). It is also included in a memorandum about protecting small sea animals in Western Africa and Macaronesia.