Sooty Shearwater
Encyclopedia
The Sooty Shearwater is a medium-large shearwater
in the seabird
family Procellariidae
. In New Zealand it is also known by its Māori
name tītī and as "muttonbird
", like its relatives the Wedge-tailed Shearwater
(P. pacificus) and the Australia
n Short-tailed Shearwater
(P. tenuirostris).
It appears to be particularly closely related to the Great
("P." gravis) and Short-tailed Shearwaters, all blunt-tailed, black-billed species, but its precise relationships are obscure. In any case, these three species are among the larger species of shearwater which might belong into a separate genus Ardenna.
Sooty Shearwaters are 40–51 cm in length with a 94–110 cm wingspan. It has the typically "shearing" flight of the genus, dipping from side to side on stiff wings with few wing beats, the wingtips almost touching the water. Its flight is powerful and direct, with wings held stiff and straight, giving the impression of a very small albatross
. This shearwater is identifiable by its dark plumage
which is responsible for its name. In poor viewing conditions it looks all black, but in good light it shows as dark chocolate-brown a silvery strip along the center of the underwing.
Usually loud, Sooty Shearwaters coo and croak while on the breeding grounds.
In the Atlantic, it is the only such bird, whereas in the Pacific part of its range, other all-dark large shearwaters are found. Particularly the Short-tailed Shearwater
is almost impossible to tell apart from the present species at a distance.
, the Falkland Islands
, Tierra del Fuego
and also in the Auckland Islands
and Phillip Island off Norfolk Island
. They start breeding in October, and incubate their young for about 54 days. Once the chick hatches, the parents raise their chicks for 86 to 109 days.
They are spectacular long-distance migrants
, following a circular route, travelling north up the western side of the Pacific and Atlantic Oceans at the end of the nesting season in March–May, reaching sub Arctic waters in June–July where they cross from west to east, then returning south down the eastern side of the oceans in September–October, reaching to the breeding colonies in November. They do not migrate as a flock, but rather as single individuals, associating only opportunistically; in June 1906 for example, two were shot near Guadalupe Island
off Baja California
(Mexico
), several weeks before the bulk of the population would pass by. Likewise, the identity of numerous large dark shearwaters observed in October 2004 off Kwajalein
in the Marshall Islands
remains enigmatic; they might have been either Sooty or Short-tailed Shearwater
s, but neither species is generally held to pass through this region at that time.
In the Atlantic Ocean, they cover distances in excess of 14000 km (8,699.2 mi) from their breeding colony on the Falkland Islands (52°S 60°W) north to 60° to 70°N in the North Atlantic Ocean off north Norway
; distances covered in the Pacific are similar or larger; although the Pacific Ocean colonies are not quite so far south, at 35° to 50°S off New Zealand, and moving north to the Aleutian Islands, the longitudinal width of the ocean makes longer migrations necessary. Recent tagging experiments have shown that birds breeding in New Zealand may travel 74,000 km in a year, reaching Japan, Alaska and California, averaging more than 500 km per day.
In Great Britain
, they move south in late August and September; with strong north and north-west winds, they may occasionally become 'trapped' in the shallow, largely enclosed North Sea
, and heavy passages may be seen flying back north up the British east coast as they re-trace their steps back to the Atlantic over northern Scotland
.
and squid
. They can dive up to 68 m deep for food, but more commonly take surface food, in particular often following whale
s to catch fish disturbed by them. They will also follow fishing boats to take fish scraps thrown overboard.
They breed in huge colonies and the female lays one white egg. These shearwaters nest in burrows lined with plant material which are visited only at night to avoid predation by large gull
s.
In New Zealand, about 250,000 mutton birds are harvested
for oils, food and fats each year by the native Māori. Young birds just about to fledge are collected from the burrows, plucked and often preserved in salt.
Its numbers have been declining in recent decades, and it is presently classified as Near Threatened
by the IUCN. In 2009 the harvest reported record low catches, on average a trapping cage would yield nearly 500 birds, in 2009 the number was estimated to be closer to 40 per cage.
Shearwater
Shearwaters are medium-sized long-winged seabirds. There are more than 30 species of shearwaters, a few larger ones in the genus Calonectris and many smaller species in the genus Puffinus...
in the seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
family Procellariidae
Procellariidae
The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes , which also includes the albatrosses, the storm-petrels, and the diving petrels.The procellariids are...
. In New Zealand it is also known by its Māori
Maori language
Māori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
name tītī and as "muttonbird
Muttonbird
Muttonbird, mutton-bird or mutton bird refer to seabirds – particularly certain large shearwaters – whose young are collected for food and other uses before they fledge ....
", like its relatives the Wedge-tailed Shearwater
Wedge-tailed Shearwater
The Wedge-tailed Shearwater, Puffinus pacificus is a medium-large shearwater in the seabird family Procellariidae. It is one of the shearwater species that is sometimes referred to as a Muttonbird, like the Sooty Shearwater of New Zealand and the Short-tailed Shearwater of Australia...
(P. pacificus) and the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n Short-tailed Shearwater
Short-tailed Shearwater
The Short-tailed Shearwater or Slender-billed Shearwater , also called Yolla or Moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in Australian waters, and is one of the few Australian native birds in which the chicks are commercially harvested...
(P. tenuirostris).
It appears to be particularly closely related to the Great
Great Shearwater
The Great Shearwater is a large shearwater in the seabird family Procellariidae. Its relationships are unclear. It belongs in the group of large species that could be separated as genus Ardenna ; within these, it might be allied with the other black-billed, blunt-tailed species Short-tailed...
("P." gravis) and Short-tailed Shearwaters, all blunt-tailed, black-billed species, but its precise relationships are obscure. In any case, these three species are among the larger species of shearwater which might belong into a separate genus Ardenna.
Description
Albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes . They range widely in the Southern Ocean and the North Pacific...
. This shearwater is identifiable by its dark plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
which is responsible for its name. In poor viewing conditions it looks all black, but in good light it shows as dark chocolate-brown a silvery strip along the center of the underwing.
Usually loud, Sooty Shearwaters coo and croak while on the breeding grounds.
In the Atlantic, it is the only such bird, whereas in the Pacific part of its range, other all-dark large shearwaters are found. Particularly the Short-tailed Shearwater
Short-tailed Shearwater
The Short-tailed Shearwater or Slender-billed Shearwater , also called Yolla or Moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in Australian waters, and is one of the few Australian native birds in which the chicks are commercially harvested...
is almost impossible to tell apart from the present species at a distance.
Distribution and movements
Sooty Shearwaters breed on small islands in the south Pacific and south Atlantic Oceans, mainly around New ZealandNew Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, the Falkland Islands
Falkland Islands
The Falkland Islands are an archipelago in the South Atlantic Ocean, located about from the coast of mainland South America. The archipelago consists of East Falkland, West Falkland and 776 lesser islands. The capital, Stanley, is on East Falkland...
, Tierra del Fuego
Tierra del Fuego
Tierra del Fuego is an archipelago off the southernmost tip of the South American mainland, across the Strait of Magellan. The archipelago consists of a main island Isla Grande de Tierra del Fuego divided between Chile and Argentina with an area of , and a group of smaller islands including Cape...
and also in the Auckland Islands
Auckland Islands
The Auckland Islands are an archipelago of the New Zealand Sub-Antarctic Islands and include Auckland Island, Adams Island, Enderby Island, Disappointment Island, Ewing Island, Rose Island, Dundas Island and Green Island, with a combined area of...
and Phillip Island off Norfolk Island
Phillip Island (Norfolk Island)
Phillip Island is an uninhabited island located south of Norfolk Island in the Southwest Pacific, and part of the Norfolk Island group. It was named in 1788 by Lieutenant Philip Gidley King for Arthur Phillip, the first Governor of New South Wales. It is part of the Australian territory of Norfolk...
. They start breeding in October, and incubate their young for about 54 days. Once the chick hatches, the parents raise their chicks for 86 to 109 days.
They are spectacular long-distance migrants
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, following a circular route, travelling north up the western side of the Pacific and Atlantic Oceans at the end of the nesting season in March–May, reaching sub Arctic waters in June–July where they cross from west to east, then returning south down the eastern side of the oceans in September–October, reaching to the breeding colonies in November. They do not migrate as a flock, but rather as single individuals, associating only opportunistically; in June 1906 for example, two were shot near Guadalupe Island
Guadalupe Island
Guadalupe Island, or Isla Guadalupe is a volcanic island located 241 kilometers off the west coast of Mexico's Baja California peninsula and some 400 kilometers southwest of the city of Ensenada in Baja California state, in the Pacific Ocean...
off Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
(Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
), several weeks before the bulk of the population would pass by. Likewise, the identity of numerous large dark shearwaters observed in October 2004 off Kwajalein
Kwajalein
Kwajalein Atoll , is part of the Republic of the Marshall Islands . The southernmost and largest island in the atoll is named Kwajalein Island. English-speaking residents of the U.S...
in the Marshall Islands
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...
remains enigmatic; they might have been either Sooty or Short-tailed Shearwater
Short-tailed Shearwater
The Short-tailed Shearwater or Slender-billed Shearwater , also called Yolla or Moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in Australian waters, and is one of the few Australian native birds in which the chicks are commercially harvested...
s, but neither species is generally held to pass through this region at that time.
In the Atlantic Ocean, they cover distances in excess of 14000 km (8,699.2 mi) from their breeding colony on the Falkland Islands (52°S 60°W) north to 60° to 70°N in the North Atlantic Ocean off north Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
; distances covered in the Pacific are similar or larger; although the Pacific Ocean colonies are not quite so far south, at 35° to 50°S off New Zealand, and moving north to the Aleutian Islands, the longitudinal width of the ocean makes longer migrations necessary. Recent tagging experiments have shown that birds breeding in New Zealand may travel 74,000 km in a year, reaching Japan, Alaska and California, averaging more than 500 km per day.
In Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
, they move south in late August and September; with strong north and north-west winds, they may occasionally become 'trapped' in the shallow, largely enclosed North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
, and heavy passages may be seen flying back north up the British east coast as they re-trace their steps back to the Atlantic over northern Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
.
Ecology and status
The Sooty Shearwater feeds on fishFish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
and squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
. They can dive up to 68 m deep for food, but more commonly take surface food, in particular often following 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...
s to catch fish disturbed by them. They will also follow fishing boats to take fish scraps thrown overboard.
They breed in huge colonies and the female lays one white egg. These shearwaters nest in burrows lined with plant material which are visited only at night to avoid predation by large gull
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
s.
In New Zealand, about 250,000 mutton birds are harvested
Muttonbirding
Muttonbirding is a seasonal harvesting activity, which may be recreational or commercial, of the chicks of petrels, especially shearwater species, for food, oil and feathers...
for oils, food and fats each year by the native Māori. Young birds just about to fledge are collected from the burrows, plucked and often preserved in salt.
Its numbers have been declining in recent decades, and it is presently classified as Near Threatened
Near Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
by the IUCN. In 2009 the harvest reported record low catches, on average a trapping cage would yield nearly 500 birds, in 2009 the number was estimated to be closer to 40 per cage.
Further reading
- Bull, John L.; Farrand, John Jr.; Rayfield, Susan & National Audubon SocietyNational Audubon SocietyThe National Audubon Society is an American non-profit environmental organization dedicated to conservation. Incorporated in 1905, Audubon is one of the oldest of such organizations in the world and uses science, education and grassroots advocacy to advance its conservation mission...
(1977): The Audubon Society field guide to North American birds, Eastern Region. Alfred A. Knopf, New York. ISBN 0-394-41405-5 - Harrison, Peter (1988): Seabirds (2nd ed.). Christopher HelmHelm Identification GuidesThe Helm Identification Guides are a series of books that identify groups of birds. The series include two types of guides, those that are:* Taxonomic, dealing with a particular family of birds on a worldwide scale—most early Helm Guides were this type, as well as many more-recent ones,...
, London. ISBN 0-7470-1410-8 - Gillson, Greg (2008): Field separation of Sooty and Short-tailed Shearwaters off the west coast of North America BirdingBirding (magazine)Birding is the bimonthly members' magazine of the American Birding Association. While not a formal journal, Birding offers enthusiasts in-depth and scholarly articles on field identification and bird conservation. Each issue also features tips on North American and foreign birdfinding, news in the...
40(2): 34-40.
External links
- Sooty Shearwater Photos
- BTO BirdFacts - Sooty Shearwater
- The Titi Project: Website of a long-term Sooty Shearwater research project in New Zealand. Recovered 2006-NOV-20
- NPRNPRNPR, formerly National Public Radio, is a privately and publicly funded non-profit membership media organization that serves as a national syndicator to a network of 900 public radio stations in the United States. NPR was created in 1970, following congressional passage of the Public Broadcasting...
: The Common Shearwater, Nature's Migration King. Day to DayDay to DayDay to Day was a one-hour weekday American radio newsmagazine distributed by National Public Radio , and produced by NPR in collaboration with Slate. Madeleine Brand served as host since 2006...
, aired August 8, 2006. Recovered 2006-NOV-20 - TerraNature The incredible journey of sooty shearwater from New Zealand to the north Pacific for an endless summer 25 April 2007
- Tītī – muttonbirding in Te Ara - the Encyclopedia of New Zealand
- * A Seaweed Pantry - Tales from Te PapaTales from Te PapaTales From Te Papa is a television series of mini-documentaries about objects from the collection of the Museum of New Zealand Te Papa Tongarewa and the activities of the Museum staff. The series is a partnership between Television New Zealand and the Museum of New Zealand Te Papa Tongarewa...
Episode 100 - a short video on muttonbirding