Hector's beaked whale

Species (main)

Published: May 3, 2011, 12:00 am

Updated: October 16, 2011, 5:36 pm

Topics:

Species (main) Conservation Biology (main) Marine Ecology (main) Animal Behavior (main) Oceans and seas (main) Ecology (main)

Hector's beaked whale. Source: Wurtz-Artescienza

Hector's beaked whale (scientific name: Mesoplodon hectori) is one of 21 species of beaked whales (Hyperoodontidae or Ziphiidae), medium-sized whales with distinctive, long and narrow beaks and dorsal fins set far back on their bodies. They are marine mammals within the order of cetaceans.

The extremely rare, Hector’s beaked whale is known from the South Atlantic, the South Pacific, and the Indian Ocean off South Africa, which made cetologists (scientists who study whales) think it was a Southern Hemisphere species, but since 1981, several strandings in California have indicated that the species also inhabits the Northern Hemisphere. Information about this cetacean is very limited.

Hector's beaked whale. Source: Nick Gales/IUCN

Size comparison of an average human against Hector's beaked whale. Source: Chris Huh

Conservation Status: Data Deficient

Scientific Classification Kingdom: Animalia Phylum:--- Chordata Class:------ Mammalia Order:-------- Cetacea Family:-------- Hyperoodontidae Genus:--------- Mesoplodon Species:-------- 'Mesoplodon hectori (Gray, 1871)

Common Names: Hector's beaked whale New Zealand beaked whale Skew-beaked whale

Physical Description

The length of adult M.hectori varies from 4.3 meters for up to 4.4 meters for females

Distribution and Movements

File:Distribution of HectorThe IUCNRed List reports:

Hector's beaked whale is considered to be a Southern Hemisphere cool temperate species (Mead 1989). The records (mostly strandings) are from southern South America, South Africa, southern Australia, and New Zealand. The single confirmed sighting record is from southwestern Australia (Gales et al. 2002). It has been posited that the species has a continuous distribution in the Atlantic and Indian oceans at least from South America to New Zealand. Although there are no actual sighting records from the central and eastern Pacific Ocean, the range may prove to be circumpolar. These animals are deemed to be relatively common around New Zealand.

Previously, it was supposed that this species may also be vagrant in southern California, where there were several strandings and a possible sighting from 1975 to 1979 (Mead 1981, Mead and Baker 1987, Rice 1998). However, the California specimens were recently recognised as a new species Mesoplodon perrini, which is found in the eastern North Pacific (Dalebout et al. 1998; Dalebout et al. 2002).

Habitat

The IUCNRed List reports:

In the only known confirmed identification of this species alive at sea, a single individual was observed in shallow waters, nearshore in Western Australia – almost definitely atypical for the species (Gales et al. 2002). Hector's beaked whale presumably occurs in deep waters beyond the edge of the continental shelf, as do other members of the genus.

Feeding Habits

Little is known of the species diet, but Hector's beaked whales are known to feed on squid, as in the case of most other beaked whales.

Threats and Conservation Status

The IUCN Red List reports:

Direct hunting has not been associated with this species. Pervasive gillnet and longline fisheries throughout the species' range raises concern that a certain degree of bycatch is likely. Even low levels of bycatch might have an impact on this species.

This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006).

As a temperate water species, Hector’s beaked whale may be vulnerable to the effects of climate change, as ocean warming may result in a shift or contraction of the species range as it tracks the occurrence of its preferred water temperatures (Learmonth et al. 2006). The effect of such changes in range size or position on this species is unknown.

Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001). While this species has not been classified with a conservation category, some scientists regard this species to be at risk.

References

1. Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. 2008. Mesoplodon hectori. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. . Downloaded on 15 May 2011.
2. Banks, R. C., R. W. McDiarmid, A. L. Gardner, and W. C. Starnes. 2003. Checklist of Vertebrates of the United States, the U.S. Territories, and Canada
3. Banks, R. C., R. W. McDiarmid, and A. L. Gardner. 1987. Checklist of Vertebrates of the United States, the U.S. Territories, and Canada. Resource Publication, no. 166. 79
4. Cox, T. M., Ragen, T. J., Read, A. J., Vos, E., Baird, R. W., Balcomb, K., Barlow, J., Caldwell, J., Cranford, T., Crum, L., D'Amico, A., D'Spain, A., Fernández, J., Finneran, J., Gentry, R., Gerth, W., Gulland, F., Hildebrand, J., Houser, D., Hullar, T., Jepson, P. D., Ketten, D., Macleod, C. D., Miller, P., Moore, S., Mountain, D., Palka, D., Ponganis, P., Rommel, S., Rowles, T., Taylor, B., Tyack, P., Wartzok, D., Gisiner, R., Mead, J. and Benner, L. 2006. Understanding the impacts of anthropogenic sound on beaked whales. Journal of Cetacean Research and Management 7(3): 177-187.
5. Dalebout, M. L., Mead, J. G., Baker, C. S., Baker, A. N. and van Helden, A. L. 2002. A new species of beaked whale Mesoplodon perrini sp. n. (Cetacea: Ziphiidae) discovered through phylogenetic analyses of mitochondrial DNA sequences. Marine Mammal Science 18(3): 577-608.
6. Dalebout, M. L., Van Helden, A., Van Waerebeek, K. and Baker, C. S. 1998. Molecular genetic identification of southern hermisphere beaked whales (Cetacea: Ziphiidae). Molecular Ecology 7: 687-694.
7. Fernández, A., Edwards, J. F., Rodriguez, F., Espinosa, A., De Los Monteros, Herraez, P., Castro, P., Jaber, J. R., Martin, V. and Arebelo, M. 2005. "Gas and fat embolic syndrome" involving a mass stranding of beaked whales (family Ziphiidae) exposed to anthropogenic sonar signals. Veterinary Pathology 42: 446-457.
8. Gales, N. J., Dalebout, M. L. and Bannister, J. L. 2002. Genetic identification and biological observation of two free-swimming beaked whales: Hector's beaked whale (Mesoplodon hectori, Gray 1871), and Gray's beaked whale (Mesoplodon grayi, von Haast, 1876). Marine Mammal Science 18(2): 544-551.
9. Gomercic, H., Gomercic, M. D., Gomericic, T., Lucic, H., Dalebout, M., Galov, A., Skrtic, D., Curkovic, S., Vukovic, S. and Huber, D. 2006. Biological aspects of Cuvier's beaked whale (Ziphius cavirostris) recorded in the Croatian part of the Adriatic Sea. European Journal of Wildlife Research 52(3): 182-187.
10. Gordon, D. (Ed.) (2009). New Zealand Inventory of Biodiversity. Volume One: Kingdom Animalia. 584 pp
11. Gray, J.E., 1871. Annals and Magazine of Natural History, ser. 4, 8:116.
12. Jepson, P. D., Arebelo, M., Deaville, R., Patterson, I. A. P., Castro, P., Baker, J. R., Degollada, E., Ross, H. M., Herraez, P., Pocknell, A. M., Rodriguez, F., Howie, F. E., Espinosa, A., Reid, R. J., Jaber, J. R., Martin, V., Cunningham, A. A. and Fernandez, A. 2003. Gas-bubble lesions in stranded cetaceans. Nature 425: 575-576.
13. Learmonth, J. A., Macleod, C. D., Santos, M. B., Pierce, G. J., Crick, H. Q. P. and Robinson, R. A. 2006. Potential effects of climate change on marine mammals. Oceanography and Marine Biology: An Annual Review 44: 431-464.
14. Malakoff, D. 2002. Suit ties whale deaths to research cruise. Science 298: 722-723.
15. Mead, J. G. 1981. First records of Mesoplodon hectori (Ziphiidae) from the northern hemisphere and a description of the adult male. Journal of Mammalogy 62: 430-432.
16. Mead, J. G. 1989. Beaked whales of the genus Mesoplodon. In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Vol. 4: River dolphins and the larger toothed whales, pp. 349-430. Academic Press.
17. Mead, J. G. and Baker, A. N. 1987. Notes on the rare beaked whale, Mesoplodon hectori (Gray). Journal of the Royal Society of New Zealand 17: 303-312.
18. Mead, James G., and Robert L. Brownell, Jr. / Wilson, Don E., and DeeAnn M. Reeder, eds. 2005. Order Cetacea. Mammal Species of the World: A Taxonomic and Geographic Reference, 3rd ed., vol. 1. 723-743
19. Perrin, W. (2010). Mesoplodon hectori (Gray, 1871). In: Perrin, W.F. World Cetacea Database. Accessed through: Perrin, W.F. World Cetacea Database on 2011-05-05
20. Rice, Dale W. 1998. Marine Mammals of the World: Systematics and Distribution. Special Publications of the Society for Marine Mammals, no. 4. ix + 231
21. Scott, M. D., Hohn, A. A., Westgate, A. J., Nicolas, J. R., Whitaker, B. R. and Campbell, W. B. 2001. A note on the release and tracking of a rehabilitated pygmy sperm whale (Kogia breviceps). Journal of Cetacean Research and Management 3(1): 87-94.
22. UNESCO-IOC Register of Marine Organisms
23. Wang, J. Y. and Yang, S. C. 2006. Unusual cetacean stranding events of Taiwan in 2004 and 2005. Journal of Cetacean Research and Management 8: 283-292.
24. Wilson, Don E., and DeeAnn M. Reeder, eds. 1993. Mammal Species of the World: A Taxonomic and Geographic Reference, 2nd ed., 3rd printing. xviii + 1207
25. Wilson, Don E., and F. Russell Cole. 2000. Common Names of Mammals of the World. xiv + 204
26. Wilson, Don E., and Sue Ruff, eds. 1999. The Smithsonian Book of North American Mammals. xxv + 750
27. van der Land, J. (2001). Tetrapoda, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 375-376

Citation

Encyclopedia of Life (2011). Hector's beaked whale. ed. C. Michael Hogan. Encyclopedia of Earth. National Council for Science and Environment. Washington DC. Retrieved from http://editors.eol.org/eoearth/wiki/Hector's_beaked_whale