Shepherd's beaked whale (''Tasmacetus shepherdi''), also commonly called Tasman's beaked whale or simply the Tasman whale, is a cetacean of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Ziphiidae Beaked whales (systematic name Ziphiidae) are a family of cetaceans noted as being one of the least known groups of mammals because of their deep-sea habitat and apparent low abundance. Only three or four of the 24 species are reasonably well-kn ...

and the only species in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Tasmacetus''. The

whale Whales are a widely distributed and diverse group of fully aquatic placental marine mammals. As an informal and colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and ...

has not been studied extensively. Only four confirmed at sea sightings have been made and 42 strandings recorded (as of 2006). It was first known to science in 1937, being named by W. R. B. Oliver after George Shepherd, curator of the Wanganui Museum, who collected the type specimen near Ohawe on the south

Taranaki Taranaki is a region in the west of New Zealand's North Island. It is named after its main geographical feature, the stratovolcano of Mount Taranaki, also known as Mount Egmont. The main centre is the city of New Plymouth. The New Plymouth D ...

coast of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

's North Island, in 1933.

Description

Adults can reach lengths of to and weigh about 2.32 to 3.48 tons. At birth they may be about long. They are robust and large-bodied for beaked whales, having a bluff

melon A melon is any of various plants of the family Cucurbitaceae with sweet, edible, and fleshy fruit. The word "melon" can refer to either the plant or specifically to the fruit. Botanically, a melon is a kind of berry, specifically a " pepo". Th ...

and a long, dolphin-like beak. It is the only species of ziphiid with a full set of functional teeth (17 to 27 pairs in both the upper and lower jaws). Adult males also have a pair of tusks at the tip of the lower jaw. They are dark brown dorsally and cream-colored ventrally, with a pale band extending up from the flipper and another pale area extending as a swathe on the posterior flank. The tall, falcate dorsal fin is set about two-thirds the way along the back.

Population and distribution

Sightings and stranding records indicate that the species has a circumpolar distribution in southern hemisphere. No population estimates exist for Shepherd's beaked whale. As of 2006, there have been about 42 stranding records of the species from New Zealand (including the

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...

, 24),

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

(7),

Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcanic islands in the South Atlantic Ocean. It is the most remote inhabited archipelago in the world, lying approximately from Cape Town in South Africa, from Saint Helena a ...

(6), Australia (3), and the

Juan Fernández Islands The Juan Fernández Islands ( es, Archipiélago Juan Fernández) are a sparsely inhabited series of islands in the South Pacific Ocean reliant on tourism and fishing. Situated off the coast of Chile, they are composed of three main volcanic i ...

(2). The northernmost record was at Shark Bay in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

in 2008. There have been five unconfirmed sightings (mostly from New Zealand), as well as a "probable" sighting near Shag Rocks and four confirmed sightings—the first two confirmed sightings occurred in 1985, within a few minutes of each other, off the Tristan da Cunha group (first sighting at ); the third in 2002 near Gough Island (); and the fourth in 2004 south of

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

(). In January 2012, a group of up to a dozen of this species were photographed and filmed by the

Australian Antarctic Division The Australian Antarctic Division (AAD) is a division of the Department of Climate Change, Energy, the Environment and Water. The Division undertakes science programs and research projects to contribute to an understanding of Antarctica and the ...

south of

Portland Portland most commonly refers to: * Portland, Oregon, the largest city in the state of Oregon, in the Pacific Northwest region of the United States * Portland, Maine, the largest city in the state of Maine, in the New England region of the northeas ...

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

. Multiple sightings of the species have been reported from Otago submarine canyons off Otago coast, New Zealand. Sightings have been recorded throughout the year with vocalization recordings, suggesting regular presences there. These include at least two sightings in 2016 which were the first confirmed sightings within New Zealand waters, followed by four sightings in 2017, one or more sighting(s) in 2018, one sighting in 2019, four or five sightings in 2021, five sightings in 2022 including a pod of 15-20 animals.Hamish MacLean, 2022,
Rare whales seen, vocalisation recorded
', The Otago Daily Times, Retrieved on February 24, 2022 There have been additional sightings from other parts of New Zealand, such as off Gisborne, several sightings off Kaikoura, off

Fiordland Fiordland is a geographical region of New Zealand in the south-western corner of the South Island, comprising the westernmost third of Southland. Most of Fiordland is dominated by the steep sides of the snow-capped Southern Alps, deep lake ...

, Taranaki, and so on.

Behaviour

Four of the confirmed sightings of this species involved three to six individuals (one group included a calf) in waters from to deep, while a 2012 sighting involved as many as ten to twelve individuals. The animals surfaced several times, before arching to dive. Some were observed to come to the surface at a steep angle like many other ziphiids, raising their head and beaks out of the water. The Shepherd's beaked whale's blow could be observed with the naked eye at a distance of up to 1,000 metres, within a bushy plume that is relatively tall for a ziphiid varying from 1 to 2 metres in height The species is seldom seen because of its deep, offshore distribution in waters where sighting conditions can be difficult (the "

Roaring Forties The Roaring Forties are strong westerly winds found in the Southern Hemisphere, generally between the latitudes of 40°S and 50°S. The strong west-to-east air currents are caused by the combination of air being displaced from the Equator ...

" and "Furious Fifties"). Research done on a stranded individual's stomach has indicated that Shepherd's beaked whales eat both fish and squid, as opposed to most beaked whales which only eat cephalopods.

Conservation

There are no reports of this species being hunted or killed accidentally by humans. Shepherd's beaked whale is covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region ( Pacific Cetaceans MOU).Official webpage of the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region
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Taxonomy

Its nearest relative, the only other living member of the subfamily Ziphiinae, is

Cuvier's beaked whale The Cuvier's beaked whale, goose-beaked whale, or ziphius (''Ziphius cavirostris'') is the most widely distributed of all beaked whales in the family Ziphiidae. It is smaller than most baleen whales yet large among beaked whales. Cuvier's beaked ...

(''Ziphius cavirostris'').

References

Sources

#''Shepherd's beaked whale'' in the ''Encyclopedia of Marine Mammals'' Thomas A. Jefferson, 1998. #''Whales, Dolphins and Porpoises'' Carwardine, 1995. {{Taxonbar, from=Q1124755 Cetaceans of the Pacific Ocean Mammals of Argentina Mammals of Chile Ziphiids Mammals described in 1937