Sowerby's beaked whale (Mesoplodon bidens)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



Mesoplodon bidens is a toothed whale and can be recognised as such by the single blowhole and the presence of teeth (rather than baleen). It is a member of the beaked whale family with the characteristic V-shaped crease on the throat and the short dorsal fin set relatively far back. Sowerby's beaked whale is a small beaked whale that can reach up to 5.5 m in length. The lower jaw has a single pair of teeth (exposed only in adult males). The forehead rises at a shallow angle and has a slight bump. It has a distinct beak and the mouthline is curved down at rear. Sowerby's beaked whale has a charcoal grey dorsal and lateral colouration with a lighter belly. Adults may also have light grey spots on the body and are often covered with scratches and scars.

Recorded distribution in Britain and Ireland

Recorded at various locations in the British Isles but most commonly seen off the north coasts of Scotland and north-east England.

Global distribution



Sowerby's beaked whale is an oceanic and coastal species that may be seen at the surface but little is known on what depth they may dive to.

Depth range


Identifying features

  • Up to 5.5 m in length.
  • Small dorsal fin two-thirds down the body.
  • Distinct, relatively long beak.
  • Small head with shallow rising forehead with a small bump.
  • Pair of V-shaped throat grooves.
  • Mouthline curved down at the rear.

Additional information

Sowerby's beaked whale may be confused with True's beaked whale Mesoplodon mirus but can be recognised by a slight bump on the forehead and a slightly longer beak. Sowerby's beaked whales are usually found either alone or in groups of up to 10 individuals. Little is known about their behaviour although tail-slapping has been recorded. Dives may last up to 15 minutes long (Kinze, 2002).


  1. Bruyns, W.F.J.M., 1971. Field guide of whales and dolphins. Amsterdam: Publishing Company Tors.

  2. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  3. Jefferson, T.A., Leatherwood, S. & Webber, M.A., 1994. FAO species identification guide. Marine mammals of the world. Rome: United Nations Environment Programme, Food and Agriculture Organization of the United Nations.

  4. Kinze, C. C., 2002. Photographic Guide to the Marine Mammals of the North Atlantic. Oxford: Oxford University Press.

  5. Reid. J.B., Evans. P.G.H., Northridge. S.P. (ed.), 2003. Atlas of Cetacean Distribution in North-west European Waters. Peterborough: Joint Nature Conservation Committee.


  1. NBN (National Biodiversity Network) Atlas. Available from:

  2. Norfolk Biodiversity Information Service, 2017. NBIS Records to December 2016. Occurrence dataset: accessed via on 2018-10-01.

  3. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-05-18

  4. Outer Hebrides Biological Recording, 2018. Vertebrates (except birds, INNS and restricted records), Outer Hebrides. Occurrence dataset: accessed via on 2018-10-01.

  5. Whale and Dolphin Conservation, 2018. WDC Shorewatch Sightings. Occurrence dataset: accessed via on 2018-10-02.


This review can be cited as:

Barnes, M.K.S. 2008. Mesoplodon bidens Sowerby's beaked whale. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 18-05-2024]. Available from:

Last Updated: 02/06/2008