White-beaked dolphin

White-beaked dolphin
Size compared to an average human
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Eutheria
Order: Cetacea
Suborder: Odontoceti
Family: Delphinidae
Genus: Lagenorhynchus
Species: L. albirostris
Binomial name
Lagenorhynchus albirostris
(Gray, 1846)
White-beaked dolphin range

The white-beaked dolphin (Lagenorhynchus albirostris) is a marine mammal belonging to the family Delphinidae (dolphins) in the suborder Odontoceti (toothed whales).

Taxonomy

The species was first described by the British taxonomist John Edward Gray in 1846. Due to its relative abundance in European waters, it was among the first of the genus Lagenorhynchus (lagenos, Latin for "bottle" or "flask"; rhynchos, "beak" or "snout") to be known to science. Its specific name, albirostris, translates to "white beak", a reference to the color of the species' beak, a diagnostic (albeit variable) trait useful in identification.[2]

Description

Skeleton

The white-beaked dolphin is a robust species of dolphin with a short beak. Adults can reach 2.3 to 3.1 m (7 ft 7 in to 10 ft 2 in) long and weigh 180 to 354 kg (397 to 780 lb). Calves are 1.1 to 1.2 m (3 ft 7 in to 3 ft 11 in) long at birth and probably weigh about 40 kg (88 lb).[3] The dolphin is characterized by its short thick creamy-white beak and very falcate (curved) dorsal fin.

Distribution

The white-beaked dolphin is endemic to the North Atlantic Ocean and is found in a band stretching across the ocean from Cape Cod, the mouth of the St. Lawrence River and southern Greenland in the west, around Iceland in the centre, and across in the west from northern France to Svalbard; however, it is not well adapted to Arctic conditions[4] as are the beluga or narwhal. The dolphin may easily be misidentified as the Atlantic white-sided dolphin, although the white-beaked is commonly found further north. The white-beaked dolphin is also typically larger, and does not have yellow streaks on its side.

Behavior

A white-beaked dolphin off Iceland

The population, breeding pattern, and life expectancy of the dolphin are all unknown, although most sources estimate several hundred thousand individuals, more densely populated in the eastern North Atlantic than the west.

White-beaked dolphins are acrobatic and social animals. They will frequently ride on the bow wave of high-speed boats and jump clear of the sea's surface. The white-beaked dolphin is a social feeder and has frequently been observed feeding with killer, fin, and humpback whales, as well as other dolphin species.

Conservation

White-beaked dolphins off south east of Old Portlethen.

The North and Baltic Sea populations of the white-beaked dolphin are listed on Appendix II[5] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), since they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.[6]

In addition, the white-beaked dolphin is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS).[7]

See also

References

  1. ↑ Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. (2008). Lagenorhynchus albirostris. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 24 March 2009.
  2. ↑ Reeves, Randall, Brent Stewart, Phillip Clapham and James Powell (2002). National Audubon Society Guide to Marine Mammals of the World. Knopf. pp. 395–397. ISBN 0-375-41141-0.
  3. ↑ Shirihai, H. and Jarrett, B. (2006). Whales, Dolphins and Other Marine Mammals of the World. Princeton Field Guides. pp. 199–200. ISBN 9780691127569.
  4. ↑ Polar bears eating dolhins as waters warm Bloomberb News, retrieved June 12, 2015
  5. ↑ "Appendix II" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5 March 2009.
  6. ↑ Convention on Migratory Species page on the White-beaked dolphin
  7. ↑ Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas

External links

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