Cuvier's beaked whale

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Cuvier's beaked whale
Wal Cuviera.jpg
Cuvier's beaked whale size.svg
Size compared to an average human
Conservation status
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Ziphiidae
Subfamily: Ziphiinae
Genus: Ziphius
Cuvier 1823
Binomial name
Ziphius cavirostris
Cetacea range map Cuvier's Beaked Whale.PNG
Cuvier's beaked whale range

Cuvier's beaked whale or the goose-beaked whale (Ziphius cavirostris), the only member of the genus Ziphius, is the most widely distributed of all the beaked whales.[1] Though it is pelagic, prefers water deeper than 1,000 m (3,300 ft) and avoids ships, it is still one of the most frequently spotted beaked whales.[2]

The species name comes from Greek xiphos, "sword", and Latin cavus, "hollow" and rostrum, "beak", referring to the indentation on the head in front of the blowhole.[3]

History of discovery[edit]

The French anatomist Georges Cuvier, in his treatise Sur les Ossemens fossiles (1823),[4] first described the species based on an imperfect skull from the Mediterranean coast of France. It had been obtained by M. Raymond Gorsse in the department of Bouches-du-Rhône, near Fos, in 1804 from a peasant who had found it on the seashore the previous year. Cuvier named it Ziphius cavirostris, the specific name being derived from the Latin cavus for "hollow" or "concave", in reference to the deep hollow (the prenarial basin) in the skull, a diagnostic trait of the species. Cuvier believed it to represent the remains of an extinct species. It wasn't until 1850 that zoologists realized the extant nature of the species, when Paul Gervais compared the type specimen to another that had stranded itself at Aresquiès, Hérault, in May of the same year, and found the two to be identical.[5] It is thought that Cuvier's beaked whales were the inspiration for the Ziphius, or Water-Owl, a creature in medieval folk-lore which had the characteristics of both an owl and a fish. It's dorsal fin was said to be sword-shaped, and pierced ship's hulls, while the beak was said to resemble an owl's head.

Physical description[edit]

Skeleton

The body of Cuvier's beaked whale is robust and cigar-shaped, similar to those of other beaked whales and can be difficult to distinguish from many of the mesoplodont whales at sea.[6] It grows up to about 5–7 m (16–23 ft) in length and weighs 2,500 kg (5,500 lb).[3] There is no significant size difference between sexes.[6]

Its dorsal fin is curved, small and located two-thirds of the body length behind the head. Its flippers are equally small and narrow and can be tucked into pockets in the body wall, presumably to prevent drag while swimming. Like other beaked whales, its flukes are large and lack the medial notch found in all other cetaceans. The head is short with a small, poorly defined rostrum and a gently sloping melon. A pair of throat grooves allow the whale to expand this region when sucking in its prey.[6]

Cuvier's beaked whale has a short beak in comparison with other species in its family, with a slightly bulbous melon. The melon is white or creamy in color and a white strip runs back to the dorsal fin about two-thirds of the way along the back. The rest of the body color varies by individual: some are dark grey; others a reddish-brown. Individuals commonly have white scars and patches caused by cookiecutter sharks. The dorsal fin varies in shape from triangular to highly falcate, whilst the fluke is about one-quarter the body length. They live for forty years.

Food and foraging[edit]

Cuvier's beaked whale feeds on several species of squid, including those in the families Cranchiidae, Onychoteuthidae, Brachioteuthidae, Enoploteuthidae, Octopoteuthidae and Histioteuthidae; it also preys on deep-sea fish.[7] In 2014, scientists reported that they had used satellite-linked tags to track Cuvier's beaked whales off the coast of California and found the animals dove up to 2,992 meters (nearly two miles) below the ocean surface and spent up to two hours and 17 minutes underwater before resurfacing, which represent both the deepest and the longest dives ever documented for any mammal.[8][9][10]

Range and habitat[edit]

Cuvier's has a cosmopolitan distribution in deep, offshore waters from the tropics to the cool temperate seas. In the North Pacific, it occurs as far north as the Aleutians and in the North Atlantic as far north as Massachusetts in the west to the Shetlands in the east. In the Southern Hemisphere, it occurs as far south as Tierra del Fuego, South Africa, southern Australia, New Zealand, and the Chatham Islands. It also frequents such inland bodies of waters as the gulfs of Mexico and likely the Caribbean and Mediterranean Seas.[11]

Cuvier’s beaked whale may be one of the most common and abundant of the beaked whales, with a worldwide population likely well over 100,000. There are estimated to be about 80,000 in the eastern tropical Pacific, nearly 1,900 off the west coast of the United States (excluding Alaska), and more than 15,000 off Hawaii. [12]

In 2011, a tagged Cuvier's beaked whale dived to a depth of 2,992 metres (9,816 ft), or 1.8 miles,[13] which is the deepest recorded dive by any mammal.[14][15]

Conservation[edit]

A stranded Cuvier's beaked whale

Japanese whalers in the past opportunistically caught Cuvier's, taking between 3 and 35 each year (before 1955).[12] The species has been reported taken incidentally in fisheries in Colombia, the Italian swordfish fishery, and in the drift gillnet fishery off the U.S. west coast, where between 22 and 44 individuals died each year off California and Oregon from 1992 to 1995.[12] Cuvier's beaked whale is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS)[16] and the Agreement on the Conservation of Cetaceans in the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS).[17] The species is further included in the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU)[18] and the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU).[19]

Beaked whales may also be sensitive to noise: a higher incidence of strandings has been recorded in noisy seas such as the Mediterranean, and multiple mass strandings have occurred following operations by the Spanish Navy.[20]

See also[edit]

Notes[edit]

References[edit]

  • Carwardine, Mark; Camm, Martin (2000). Whales, Dolphins and Porpoises. London: Dorling Kindersley. ISBN 0-7513-2781-6. 
  • Cuvier, Georges (1823). Recherches sur les ossemens fossiles (in French) 5.1 (2nd ed.). Paris. pp. 350–2, fig. 7. Retrieved February 2013. 
  • Evans, Peter GH (1987). The Natural History of Whales and Dolphins. New York: Facts on File Publications. ISBN 0816017328. OCLC 14271801. 
  • Heyning, John E (2002). "Cuvier's Beaked Whale". In Jefferson, Thomas A. Encyclopedia of Marine Mammals. Academic Press. pp. 305–7. ISBN 0-12-551340-2. 
  • "Cuvier's Beaked Whales, Ziphius cavirostris". MarineBio Conservation Society. 2013. Retrieved February 2013. 
  • Grzimek, Bernhard (2003). Hutchins, Michael; Kleiman, Devra G.; Geist, Valerius et al., eds. Grzimek's Animal Life Encyclopedia, Vol 15, Mammals IV (2nd ed.). Farmington Hills, MI: Gale Group. ISBN 0-7876-5362-4. 
  • Reeves, Randall R; Stewart, Brent S; Clapham, Phillip J; Powell, James A (2002). National Audubon Society Guide to Marine Mammals of the World. Alfred A. Knopf. p. 254. ISBN 0375411410. 
  • Taylor, BL; Baird, R; Barlow, J; Dawson, SM; Ford, J; Mead, JG; Notarbartolo di Sciara, G; Wade, P; Pitman, RL (2008). "Ziphius cavirostris". IUCN. Retrieved February 2013. 
  • Turner, W (1872). "On the occurrence of Ziphius cavirostris in the Shetland Seas, and a comparison of its skull with that of Sowerby’s whale (Mesoplodon Sowerbyi)". Transactions of the Royal Society of Edinburgh (Edinburgh) 26 (4): 759–80. doi:10.1017/s0080456800025618. OCLC 26145032. 

External links[edit]