Mesoplodon grayi von
English: Gray's beaked whale
Spanish: Zifio de Gray, ballena picuda de Gray
French: Mésoplodon de Gray
Mesoplodon Grayi © Wurtz-Artescienza (see links).
Adults are dark grey, with pale patches on the under-sides. The
small head leads to a narrow beak which becomes white in adulthood.
The tips of two relatively small, triangular teeth erupt from the
lower jaw in males, about one half from the tip of the beak. There
are 17-22 pairs of small teeth in the posterior half of the upper
jaw. Maximum body size was 5.6m in males and 5.3 m in females (Jefferson
et al. 2008). Body mass in adults reaches 1,100 kg; size of newborn
calves ranges between 2.1 and 2.4 m (Reidenberg and Laitman, 2009).
Gray's beaked whale is circumglobal in cool-temperate waters of
the Southern Hemisphere, with specimen records from Argentina (Tierra
del Fuego, Chubut, and Buenos Aires), Brazil, Falkland Islands/lslas
Malvinas, the Estrecho de Magallanes in Chile, Peru (Paracas), Cape
Province in South Africa, 31°S, 47°E, in the Indian Ocean,
Western Australia, South Australia, Victoria, New South Wales, Tasmania,
New Zealand, Chatham Islands, (Rice, 1998).
Distribution of Mesoplodon grayi (Taylor
et al. 2008; © IUCN; enlarge
map). The species is found in
cold temperate waters of the Southern Hemisphere and ranges South
into Antarctic waters
(Pitman, 2002, Jefferson et al. 2008).
There are many sighting records from Antarctic and
sub-Antarctic waters, and in the summer months they appear near
the Antarctic Peninsula and along the shores of the continent (sometimes
in the sea ice; Van Waerebeek et al., 2004; Taylor et al. 2008).
Gray's beaked whale is the most common beaked whale species to strand
in New Zealand and a cluster of sightings in the area between the
South Island of New Zealand and the Chatham Islands may indicate
a distributional "hot spot" (Dalebout et al. 2004). There
is a record from Brazil (Soto and Vega, 1997), which extends the
northern limit of the distribution (Pinedo et al. 2001).
3. Population size
Unknown, although this is one of the more common and widespread
mesoplodont whales in the Southern Ocean (Pitman, 2002, 2009). In
New Zealand, it is known from both North and South Islands, where
it is the second commonest single stranding species after Kogia
breviceps, with 180 recorded specimens (Van Waerebeek et
4. Biology and Behaviour
The species is rarely seen at sea due to their oceanic distribution,
deep diving ability, elusive behaviour, and possible low abundance
(Dalebout et al. 2004). There are an increasing number of confirmed
sightings reported from the Southern Ocean in a circumpolar distribution
(Van Waerebeek et al. 2004), although most available information
is still from stranded animals.
M. grayi appears to be social, which is unusual for beaked
whales (but see other species accounts). The limited number of sightings
suggests that M. grayi may be more conspicuous at the surface
than other beaked whales: it seems to be more active and may live
in larger groups. Most animals were observed singly, in pairs, and
in small groups, but a mass stranding of 28 animals in the Chatham
Islands, east of New Zealand, in 1874 suggests that fairly large
numbers may be encountered together (Carwardine, 1995).
The occurrence of early foetuses in May, near-term foetuses in
September, and mother with calves in January-February indicates
summer breeding in the New Zealand region (Van Waerebeek et al.,
Unknown, however strandings between 30°S and 50°S occur
most frequently from December through March, suggesting an inshore
movement in summer (Van Waerebeek et al., 2004).
Ship strike: An adult female observed in Mahurangi Harbour,
near Warkworth, on the North Island of New Zealand had a series
of deep corrugated scars behind her dorsal fin, likely the result
of a ship strike (Dalebout et al. 2004).
Range states: Argentina; Australia ; Brazil; Chile; Falkland
Islands (Malvinas); Heard Island and McDonald Islands; Maldives;
New Zealand; Peru; South Africa; South Georgia and the South Sandwich
Islands ; Uruguay (Taylor et al. 2008).
The species is categorised as "Data Deficient" by the
IUCN. Gray's beaked whale is not listed by CMS, but because it also
occurs in southern South America, the recommendations listed in
Hucke-Gaete (2000) also apply (see Appendix
1). The species is listed in Appendix II of CITES.
8. Sources and further information
Mesoplodon - Beaked whales: Introduction and Sources"
© Boris Culik (2010) Odontocetes.
The toothed whales: "Mesoplodon grayi". UNEP/CMS
Secretariat, Bonn, Germany. http://www.cms.int/reports/small_cetaceans/index.htm
© Illustrations by Maurizio Würtz, Artescienza.
© Maps by IUCN.