Ziphius cavirostris, G. Cuvier, 1823
|
publication ID |
https://doi.org/ 10.5281/zenodo.6608481 |
|
DOI |
https://doi.org/10.5281/zenodo.6608503 |
|
persistent identifier |
https://treatment.plazi.org/id/035387C7-FFC5-FFAA-FA7A-1E1CFBE8F57E |
|
treatment provided by |
Diego |
|
scientific name |
Ziphius cavirostris |
| status |
|
Cuvier’s Beaked Whale
Ziphius cavirostris View in CoL
French: Baleine-a-bec de Cuvier / German: Cuvier-Schnabelwal / Spanish: Zifio de Cuvier
Other common names: Goose-beaked Whale, Goosebeak Whale
Taxonomy. Ziphius cavirostrnis G. Cuvier, 1823 ,
France, “dans le département des Bouches-du-Rhone, entre de Fos et I’embouchure du Galégeon” (= between Fos and the mouth of the Galégeon River).
No subspecies are currently recognized, but further research may reveal genetic differences between populations in different ocean areas. Monotypic.
Distribution. All warm temperate to tropical waters of the world and perhaps in cooler waters in the Southern Ocean and the N Pacific Ocean. It is the only species of beaked whales that commonly occurs in the Mediterranean Sea. View Figure
Descriptive notes. Total length 600-700 cm; weight 2500-3500 kg. Body of Cuvier’s Beaked Whale is spindle-shaped, with greatest girth around its midpoint. Flukes are wide in relation to body length, and tailstock is compressed laterally. Dorsalfin is small and set approximately two-thirds the distance between tip of the beak and end of the tail. Coloration is typically dark brown or dark gray. Adults of both sexes may have paler heads. In adult males, the pale head is usually very distinct, and a pale patch extends backward from it as far as the dorsal fin. Dorsal surface of adult males may also be covered in pale linear scars that are concentrated between head and dorsal fin. Rostrum and lower jaw form a short beak that is barely distinguishable from the bulbous forehead; there are two grooves on the throat. Adult males have a pair of conical tusksat the tip of the lowerjaw that may become worn down as far as the gums in older individuals.
Habitat. Deep, oceanic waters and generally in areas where water depths are more than 500 m. Cuvier’s Beaked Whales appearto favor areas with complex seabed topography and are most commonly recorded in canyons along the shelf margins, around oceanic islands, or around seamounts.
Food and Feeding. Cuvier’s Beaked Whales primarily prey on deep-water squid, but they may consume deep-water crustaceans in some parts of their distribution. They primarily consume a very narrow range of prey sizes, with most prey being 0-5-7% of an individual whale’s total body length, with a clear mode at 2-3%. Prey capture is almost certainly achieved by suction feeding. Information from dive tags suggests that most foraging of Cuvier’s Beaked Whales occurs at or near the seabed and that they spend ¢.67% oftheir life at water depths greater than 1000 m. Individual dives are commonly longer than 30 minutes and may last more than an hour.
Breeding. Cuvier’'s Beaked Whales become sexually mature at a body length of ¢.580 cm for females and ¢.550 cm for males. Gestation lasts ¢.12 months, and a single offspring is born at a length of ¢.270 cm. Weaning is thought to occur after one year; there may be a minimum of two years between successive offspring for individual females. Nothing is known of their courtship behavior, but it appears that males engage In aggressive interactions, using their tusks, which results in high levels of scarring on the dorsal surface from the head to as far back as the dorsal fin.
Activity patterns. There is no specific information available for this species, but the majority of their time is spent foraging at depths greater than 500 m.
Movements, Home range and Social organization. Although little is known about movements or home ranges of individual Cuvier’s Beaked Whales, the same individuals have been encountered in the same area repeatedly over several years, which suggests that there is some degree ofsite fidelity. There is evidence of seasonal movements in some parts of the world, such as the north-eastern Atlantic Ocean. In other places, Cuvier’s Beaked Whales appear to be present throughout the year. They typically occur in small groups of one to five individuals, and groups of more than ten are rare. Some groups consist solely of females and their offspring, but a single adult male may also be present in some groups.
Status and Conservation. CITES Appendix II. Classified as Least Concern on The IUCN Red List, but the Mediterranean subpopulation is classified as Data Deficient. There are no estimates of the global population size of Cuvier’s Beaked Whales, although estimates are available from some regions. For example, a population of ¢.80,000 individuals has been estimated for the eastern tropical Pacific Ocean and c.15,000 for the waters around Hawaii. This would suggest that Cuvier’s Beaked Whale is one of the most abundant species of beaked whale in these regions. It has been taken in small numbers by whalersin several parts of the world, including Japan, but has never been the target of a full-scale commercial fishery. It is one of the main species that has been affected by mass strandings associated with the use of mid-frequency military sonars, which may have conservation implications for local populations. Cuvier’s Beaked Whales may also be affected by overfishing of deep-water ecosystems. They occasionally occur as bycatch in driftnet fisheries. Plastic debris is commonly recorded in the stomachs of Cuvier’s Beaked Whales. In some parts of the world, such as the north-eastern Atlantic Ocean,as many as 80% of individuals contain plastic debris at the time of death. This plastic can cause erosion to the stomach lining and has been implicated in the deaths of several individuals. Nevertheless, effects of these impacts on oceanic species are difficult to study and quantify, and it is not currently known how great a threat they are to Cuvier’s Beaked Whales as a whole or to individual populations or subpopulations.
Bibliography. Baird et al. (2009), Dalebout et al. (2005), Evans, D.L. et al. (2001), Frantzis (1998), Heyning (1989b), Johnson et al. (2004), MacLeod (2006), MacLeod, Perrin et al. (2006), MacLeod, Pierce & Santos (2004), MacLeod, Santos & Pierce (2003), McSweeney et al. (2007), Rice (1998).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
