Shepherd's Beaked Whale
Encyclopedia
Shepherd's beaked whale (Tasmacetus shepherdi), also commonly called Tasman's beaked whale or simply the Tasman whale, is a cetacean of the family
Ziphidae. The whale
has been little studied. 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, former curator of the Wanganui Museum
, who collected the type specimen near Ōhawe on the south Taranaki coast, North Island
, New Zealand, in 1933.
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.
, 24), Argentina
(7), Tristan da Cunha
(6), Australia (3), and the Juan Fernández Islands
(2). 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 year, off the Tristan da Cunha group (first sighting at 37°18'S, 12°32'W); the third in 2002 near Gough Island
(40°19'S, 9°53'W); and the fourth in 2004 south of Tasmania
(48°50'S, 150°06'E).
The species is seldom seen because of its deep, offshore distribution in waters where sighting conditions can be difficult (the "Roaring Forties" and "Furious Fifties").
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Ziphidae. The whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
has been little studied. Only four confirmed at sea sightings have been made and 42 strandings
Beached whale
A beached whale is a whale that has stranded itself on land, usually on a beach. Beached whales often die due to dehydration, the body collapsing under its own weight, or drowning when high tide covers the blowhole.-Species:...
recorded (as of 2006). It was first known to science in 1937, being named by W. R. B. Oliver
Walter Oliver
Walter Reginald Brook Oliver was an Australian-born New Zealand naturalist, ornithologist, malacologist and museum curator.Born in Launceston, Tasmania, Oliver emigrated with his family to Tauranga in 1896...
after George Shepherd, former curator of the Wanganui Museum
Whanganui
Various places in New Zealand are called Whanganui:*Whanganui, a city at the mouth of the Whanganui River, also often spelled "Wanganui", Manawatu-Wanganui Region*Whanganui District, Manawatu-Wanganui Region*Whanganui Island, Waikato Region...
, who collected the type specimen near Ōhawe on the south Taranaki coast, North Island
North Island
The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...
, New Zealand, in 1933.
Physical description
Adults can reach lengths of 6 metres (19.7 ft) to 7.1 metres (23.3 ft) and weigh about 2.32 to 3.48 tons. At birth they may be about 3 metres (9.8 ft) long. They are robust and large-bodied for beaked whales, having a bluff melonMelon (whale)
The melon is an ovoid-shaped, fatty organ found in the forehead of all toothed whales , including dolphins and porpoises and believed to be used in echolocation....
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
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 IslandsChatham Islands
The Chatham Islands are an archipelago and New Zealand territory in the Pacific Ocean consisting of about ten islands within a radius, the largest of which are Chatham Island and Pitt Island. Their name in the indigenous language, Moriori, means Misty Sun...
, 24), Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
(7), Tristan da Cunha
Tristan da Cunha
Tristan da Cunha is a remote volcanic group of islands in the south Atlantic Ocean and the main island of that group. It is the most remote inhabited archipelago in the world, lying from the nearest land, South Africa, and from South America...
(6), Australia (3), and the Juan Fernández Islands
Juan Fernández Islands
The Juan Fernández Islands are a sparsely inhabited island group reliant on tourism and fishing in the South Pacific Ocean, situated about off the coast of Chile, and is composed of three main volcanic islands; Robinson Crusoe Island, Alejandro Selkirk Island and Santa Clara Island, the first...
(2). 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 year, off the Tristan da Cunha group (first sighting at 37°18'S, 12°32'W); the third in 2002 near Gough Island
Gough Island
Gough Island , also known historically as Gonçalo Álvares or Diego Alvarez, is a volcanic island in the South Atlantic Ocean. It is a dependency of Tristan da Cunha and part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha...
(40°19'S, 9°53'W); and the fourth in 2004 south of Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
(48°50'S, 150°06'E).
Behaviour
The few confirmed sightings of this species involved three to six individuals (one group included a calf) in waters from 350 metres (1,148.3 ft) to 3600 metres (11,811 ft) deep. The animals surfaced several times, giving a "small, bushy" blow (only visible from the aerial sightings), 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 species is seldom seen because of its deep, offshore distribution in waters where sighting conditions can be difficult (the "Roaring Forties" and "Furious Fifties").
Sources
- Shepherd's beaked whale in the Encyclopedia of Marine Mammals Thomas A. Jefferson, 1998. ISBN 0-12-551340-2
- Whales, Dolphins and Porpoises Carwardine, 1995. ISBN 0-7513-2781-6