|Scientific Name:||Mesoplodon grayi|
|Species Authority:||Von Haast, 1876|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor/s:||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.|
|Reviewer/s:||Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)|
There is no information on global abundance or trends in abundance for this species. It is not believed to be uncommon but it is potentially vulnerable to low-level threats and a 30% global reduction over three generations cannot be ruled out (criterion A).
|Range Description:||Gray’s beaked whale is primarily a southern Hemisphere cool temperate species, which is apparently circum-Antarctic in occurrence (Mead 1989, MacLeod et al. 2006). Most records are from south of 30°S. There are many sighting records from Antarctic and sub-Antarctic waters, and in summer months they appear near the Antarctic Peninsula and along the shores of the continent (sometimes in the sea ice). Many of the stranding records are from New Zealand, southern Australia, South Africa, Argentina, Chile, and Peru. The area between the south island of New Zealand and the Chatham Islands has been suggested to be a “hot spot” for sightings of this species (Dalebout et al. 2004). There is one record of a Gray’s beaked whale straying into the Northern Hemisphere, a stranding record in the Netherlands (Boschma 1950). This was almost certainly an extralimital occurrence.|
Native:Argentina (Buenos Aires, Chubut, Tierra del Fuego); Australia (New South Wales, South Australia, Tasmania, Victoria, Western Australia); Brazil; Chile; Falkland Islands (Malvinas); French Southern Territories (Amsterdam-St. Paul Is., Crozet Is., Kerguelen); Heard Island and McDonald Islands; Maldives; New Zealand (Antipodean Is., Chatham Is., Kermadec Is.); Peru; South Africa (Marion-Prince Edward Is.); South Georgia and the South Sandwich Islands (South Georgia); Uruguay
|FAO Marine Fishing Areas:||
Atlantic – Antarctic; Atlantic – southeast; Atlantic – southwest; Indian Ocean – Antarctic; Indian Ocean – eastern; Indian Ocean – western; Pacific – southeast; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species may not be as rare as some other species of the genus Mesoplodon, based on the number of records. In particular, they seem to be fairly common around New Zealand based on the frequency of strandings (Baker 1999). However, there are no estimates of abundance. There is no information on trends in the global abundance of this species.|
|Habitat and Ecology:||
Gray's beaked whale primarily occurs in deep waters beyond the edge of the continental shelf. Some sightings have been made in very shallow water; usually of sick animals coming in to strand (Gales et al. 2002, Dalebout et al. 2004).
Like other mesoplodonts, Gray’s beaked whales are thought to feed mainly on cephalopods in deep waters.
Direct hunting has never been associated with this species. Pervasive gillnet and longline fisheries throughout the species' range raises concern that some bycatch is likely. Even low levels of bycatch might cause unsustainable impacts on this group of naturally rare cetaceans.
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 cold water species, Gray’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); this species may also be at risk.
|Conservation Actions:||The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.|
Baker, A. N. 1999. Whales and dolphins of New Zealand and Australia: An identification guide. Victoria University Press (3rd edition), Wellington, Australia.
Balcomb, K. C. and Claridge, D. E. 2001. A mass stranding of cetaceans caused by naval sonar in the Bahamas. Bahamas Journal of Science 8(2): 2-12.
Barlow, J. 1999. Trackline detection probability for long-diving whales. In: G. W. Garner, S. C. Amstrup, J. L. Laake, B. J. F. Manley, L. L. McDonald and D. G. Robertson (eds), Marine mammal survey and assessment methods, pp. 209-221. Balkema Press, Netherlands.
Boschma, H. 1950. Maxillary teeth in specimens of Hyperoodon rostratus (Muller) and Mesoplodon grayi Von Haast stranded on the Dutch coasts. Koninklijke Nederlandse Akademie van Wetenschappen 53: 775-786.
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.
Dalebout, M. L. 2002. Species identity, genetic diversity, and molecular systematic relationships among the Ziphiidae (beaked whales). Thesis, University of Auckland.
Dalebout, M. L., Russell, C. G., Little, M. J. and Ensor, P. 2004. Observations of live Gray's beaked whales (Mesoplodon grayi) in Mahurangi Harbour, North Island, New Zealand, with a summary of at-sea sightings. Journal of the Royal Society of New Zealand 34: 347-356.
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.
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.
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.
IUCN. 2008. 2008 IUCN Red List of Threatened Species. Available at: http://www.iucnredlist.org. (Accessed: 5 October 2008).
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.
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.
Macleod, C. D., Perrin, W. F., Pitman, R. L., Barlow, J., Balance, L., D'amico, A., Gerrodette, T., Joyce, G., Mullin, K. D., Palka, D. L. and Waring, G. T. 2006. Known and inferred distributions of beaked whale species (Ziphiidae: Cetacea). Journal of Cetacean Research and Management 7(3): 271-286.
Malakoff, D. 2002. Suit ties whale deaths to research cruise. Science 298: 722-723.
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.
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.
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.
|Citation:||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 grayi. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 05 December 2013.|