Sowerby's Beaked Whale
Encyclopedia
Sowerby's beaked whale (Mesoplodon bidens), also known as the North Atlantic/North Sea beaked whale, was the first beaked whale
to be described. James Sowerby
, an English
naturalist
and artist
, first described the species in 1804 from a skull obtained from a male that had stranded in the Moray Firth
, Scotland
, in 1800. He named it bidens, which derives from the two teeth present in the jaw, now known to be a very common feature among the genus
.
is slightly convex. The colouration pattern is a grey with light countershading
on the bottom, and frequently has cookie cutter shark bites and scars from teeth (in males). The whale reaches 5 metres (16 ft) in females and 5.5 metres (18 ft) in males, with a weight of 1000-1300 kilogram
s (2200-2900 lb). The gestation period lasts for 12 months and the young are born at a length of 2.4 to 2.7 metres (8 to 9 ft) with a weight of around 185 kilograms (400 lb).
in the western North Atlantic and from Madeira
to the Norwegian Sea
in the eastern North Atlantic. They typically range in waters 200 to 1,500 metres (650 to 5,000 ft) deep. No population estimates have been made. As of 1991, there are about 90 records of the species, 80 from the eastern North Atlantic and less than ten from the western North Atlantic; the majority of the records are from around the British Isles.
On January 10, 2009, a female Sowerby's beaked whale was found at the port of Fethiye
on the Aegean
coast of Turkey
, far away from her natural habitat. The whale was successfully saved and released back to the open sea.
and molluscs, but cod
has also been found in their stomachs. They have been known to dive down at times approaching 30 minutes.
, but such practices have long since been abandoned. There are some deaths due to entanglement in fishing gear, but it is unlikely to be very damaging to the species.
Beaked whale
Beaked whales are 21 species of toothed whales, members of the family Ziphiidae, are notable for their elongated beaks. Beaked whales are one of the world's most extreme divers. They can dive for long periods—20 to 30 minutes is common, and 85 minute dives have been recorded—and to...
to be described. James Sowerby
James Sowerby
James Sowerby was an English naturalist and illustrator. Contributions to published works, such as A Specimen of the Botany of New Holland or English Botany, include his detailed and appealing plates...
, an English
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
naturalist
Naturalist
Naturalist may refer to:* Practitioner of natural history* Conservationist* Advocate of naturalism * Naturalist , autobiography-See also:* The American Naturalist, periodical* Naturalism...
and artist
Artist
An artist is a person engaged in one or more of any of a broad spectrum of activities related to creating art, practicing the arts and/or demonstrating an art. The common usage in both everyday speech and academic discourse is a practitioner in the visual arts only...
, first described the species in 1804 from a skull obtained from a male that had stranded in the Moray Firth
Moray Firth
The Moray Firth is a roughly triangular inlet of the North Sea, north and east of Inverness, which is in the Highland council area of north of Scotland...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, in 1800. He named it bidens, which derives from the two teeth present in the jaw, now known to be a very common feature among the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
.
Physical description
Sowerby's beaked whale has a typical body shape for the genus, and is mainly distinguished by the male's dual teeth positioned far back in the mouth. The whale's beak is moderately long, and the melonMelon (whale)
The melon is an ovoid-shaped, fatty organ found in the forehead of all toothed whales , including dolphins and porpoises and believed to be used in echolocation....
is slightly convex. The colouration pattern is a grey with light countershading
Countershading
Countershading, or Thayer's Law, is a form of camouflage. Countershading, in which an animal’s pigmentation is darker dorsally, is often thought to have an adaptive effect of reducing conspicuous shadows cast on the ventral region of an animal’s body...
on the bottom, and frequently has cookie cutter shark bites and scars from teeth (in males). The whale reaches 5 metres (16 ft) in females and 5.5 metres (18 ft) in males, with a weight of 1000-1300 kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
s (2200-2900 lb). The gestation period lasts for 12 months and the young are born at a length of 2.4 to 2.7 metres (8 to 9 ft) with a weight of around 185 kilograms (400 lb).
Population and distribution
Sowerby's beaked whale ranges from Nantucket to LabradorLabrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...
in the western North Atlantic and from Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
to the Norwegian Sea
Norwegian Sea
The Norwegian Sea is a marginal sea in the North Atlantic Ocean, northwest of Norway. It is located between the North Sea and the Greenland Sea and adjoins the North Atlantic Ocean to the west and the Barents Sea to the northeast. In the southwest, it is separated from the Atlantic Ocean by a...
in the eastern North Atlantic. They typically range in waters 200 to 1,500 metres (650 to 5,000 ft) deep. No population estimates have been made. As of 1991, there are about 90 records of the species, 80 from the eastern North Atlantic and less than ten from the western North Atlantic; the majority of the records are from around the British Isles.
On January 10, 2009, a female Sowerby's beaked whale was found at the port of Fethiye
Fethiye
Fethiye is a city and district of Muğla Province in the Aegean region of Turkey with about 68,000 inhabitants .-History:...
on the Aegean
Aegean Sea
The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...
coast of Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
, far away from her natural habitat. The whale was successfully saved and released back to the open sea.
Behaviour
Sowerby’s beaked whales are reclusive creatures that stay away from ships and are rarely sighted. The whales are occasionally in groups of 8 to 10 individuals (males, females, and calves) and have been known to strand in groups as well. They are believed to primarily feed on squidSquid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
and molluscs, but cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
has also been found in their stomachs. They have been known to dive down at times approaching 30 minutes.
Conservation
The species has been hunted infrequently by NorwegiansNorway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, but such practices have long since been abandoned. There are some deaths due to entanglement in fishing gear, but it is unlikely to be very damaging to the species.