The
Sooty Tern, Onychoprion fuscatus (formerly
Sterna fuscata), is a
seabirdSeabirds 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...
of the
ternTerns are seabirds in the family Sternidae, previously considered a subfamily of the gull family Laridae . They form a lineage with the gulls and skimmers which in turn is related to skuas and auks...
familyIn 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...
(Sternidae). It is a bird of the tropical oceans, breeding on islands throughout the
equatorAn equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
ial zone. Colloquially, it is known as the
Wideawake Tern or just
wideawake. This refers to the incessant calls produced by a colony of these birds, as does the Hawaiian name ʻewa ʻewa which roughly means "cacophony". In most of
PolynesiaPolynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
its name is manutara or similar however – literally "tern-bird", though it might be better rendered in English as "the tern" or "common tern". This refers to the fact that wherever Polynesian seafarers went on their long voyages, they would find these birds, and usually in astounding numbers.
Description
This is a large tern, similar in size to the
Sandwich Tern (
Thalasseus sandvicensis) at 33–36 cm (13–14 in) long with a 82–94 cm (34–37 in) wingspan. The wings and deeply forked tail are long, and it has dark black upperparts and white underparts. It has black legs and bill. The average life span is 32 years. Juvenile Sooty Terns are scaly grey above and below. The Sooty Tern is unlikely to be confused with any tern apart from the similarly dark-backed but smaller
Bridled TernThe Bridled Tern is a seabird of the tern family Sternidae. It is a bird of the tropical oceans.-Description:...
(
O. anaethetus). It is darker-backed than that species, and has a broader white forehead and no pale neck collar.
The call is a loud piercing
ker-wack-a-wack or
kvaark.
Taxonomy
The Sooty Tern has little
interspecificInterspecific is a term used in biology to describe behaviors, biochemical variations and other issues between individuals of separate species, thereby contrasting with intraspecific...
variation, but it can be divided into at least two allopatric
subspeciesSubspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
. Some recent authors further subdivide the Indopacific population into up to 8 subspecies altogether, but much of the variation is really
clinalIn biology, an ecocline or simply cline describes an ecotone in which a series of biocommunities display continuous gradient...
. The affinities of the eastern Pacific birds (including the famous
manutara of
Easter IslandEaster Island is a Polynesian island in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian triangle. A special territory of Chile that was annexed in 1888, Easter Island is famous for its 887 extant monumental statues, called moai, created by the early Rapanui people...
) are most strongly contested.
Onychoprion fuscatus fuscatus
(Linnaeus, 1766) –
Atlantic Sooty Tern
Underparts white. Breeds Atlantic and
CaribbeanThe Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
.
Onychoprion fuscatus nubilosus
(Sparrman, 1788) –
Indopacific Sooty Tern
Underparts light grey in fresh plumage, dull white in worn plumage. Breeds from
Red SeaThe Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
across
Indian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
to at least central Pacific. Some authors restrict this
taxon|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
to the Indian Ocean population and use the following subspecies for the birds from
IndonesiaIndonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
to the
AmericasThe Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
:
- Onychoprion fuscatus infuscatus – Sunda Sooty Tern (Lichtenstein, 1823) – Sunda Islands
The Sunda Islands are a group of islands that form part of the Malay archipelago.They are further divided into the Greater Sunda Islands and the Lesser Sunda Islands.-Administration:...
and vicinity
- Onychoprion fuscatus oahuensis – Central Pacific Sooty Tern (Bloxam, 1826) – Bonin Islands through Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....
to southern PolynesiaPolynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
- Onychoprion fuscatus serrata – Melanesian Sooty Tern (Wagler, 1830) – 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...
, New GuineaNew Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, New CaledoniaNew Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
- Onychoprion fuscatus luctuosa – Juan Fernández Sooty Tern (Philippi & Landbeck, 1866) – 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...
- Onychoprion fuscatus crissalis – East Pacific Sooty Tern Lawrence, 1872 – Eastern Pacific from 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...
to Galápagos IslandsThe Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
- Onychoprion fuscatus kermadeci – Kermadec Sooty Tern Mathews, 1916 – Kermadec Islands
The Kermadec Islands are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga...
- Onychoprion fuscatus somaliensis – Somali Sooty Tern – Maydh Island (Gulf of Aden
The Gulf of Aden is located in the Arabian Sea between Yemen, on the south coast of the Arabian Peninsula, and Somalia in the Horn of Africa. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, which is about 20 miles wide....
)
Ecology
Sooty Terns breed in colonies on rocky or
coralCorals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
islands. It nests in a ground scrape or hole and lays one to three eggs. It feeds by picking
fishFish 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...
from the surface in marine environments, often in large flocks, and rarely comes to land except to breed, and can stay out to sea (either soaring or floating on the water) for 3 to 10 years.
This bird is
migratoryBird 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...
and dispersive, wintering more widely through the tropical oceans. It has very marine habits compared to most terns; Sooty Terns are generally found inland only after severe
stormA storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface, and strongly implying severe weather...
s. The Field Museum, for example, has a male specimen which was found exhausted on August 2, 1933 on the slopes of
Mount CameroonMount Cameroon is an active volcano in Cameroon near the Gulf of Guinea. Mount Cameroon is also known as Cameroon Mountain or Fako or by its native name Mongo ma Ndemi ....
above
BueaBuea is the capital of the Southwest Region of Cameroon. The town is located on the eastern slopes of Mount Cameroon and has a population of 90,088 . Buea was the colonial capital of the German Kamerun from 1901 to 1919,and the capital of the Southern Cameroons from 1949 until 1961...
, about 1,000 m (3,500 ft)
ASLThe term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
, after foul weather had hit the
Gulf of GuineaThe Gulf of Guinea is the northeasternmost part of the tropical Atlantic Ocean between Cape Lopez in Gabon, north and west to Cape Palmas in Liberia. The intersection of the Equator and Prime Meridian is in the gulf....
. This species is a rare vagrant to western
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, although a bird was present at
Cemlyn BayCemlyn Bay is a bay on the northwest coast of Anglesey, North Wales, approximately 2.5 km west of Wylfa nuclear power station, within the parish of Llanfairynghornwy....
,
WalesWales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
for 11 days in July 2005.
It is also not normally found on the Pacific coasts of the
AmericasThe Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
due to its pelagic habits. At
Baja CaliforniaBaja 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...
, where several nesting locations are offshore, it can be seen more frequently, whereas for example only two individuals have ever been recorded on the coast of
El SalvadorEl Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...
- one
ringBird ringing or bird banding is a technique used in the study of wild birds, by attaching a small, individually numbered, metal or plastic tag to their legs or wings, so that various aspects of the bird's life can be studied by the ability to re-find the same individual later...
recovered in 1972, and a bird photographed on October 10, 2001 at
Lake OlomegaLake Olomega is a large lake in the southeastern part of El Salvador.In the past few years Lake Olomega has suffered from an infestation of Water hyacinth which has caused problems for wildlife, fishing, and tourism....
which was probably blown there by a storm . Hurricanes can also devastate small breeding colonies, as has been surmised for example for the Sooty Tern nesting sites on
cayA cay , also spelled caye or key, is a small, low-elevation, sandy island formed on the surface of coral reefs. Cays occur in tropical environments throughout the Pacific, Atlantic and Indian Oceans , where they provide habitable and agricultural land for hundreds of thousands of people...
s off the San Andrés Islands of
ColombiaColombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
.
An exceptionally common bird, the Sooty Tern is not considered threatened by the IUCN.
Role in Easter Island culture
On
Easter IslandEaster Island is a Polynesian island in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian triangle. A special territory of Chile that was annexed in 1888, Easter Island is famous for its 887 extant monumental statues, called moai, created by the early Rapanui people...
, this species and the Spectacled Tern (
O. lunatus) are collectively known as
manutara. The
manutara played an important role in the
tangata manuThe Tangata manu , was the winner of a traditional competition on Rapa Nui . The ritual was an annual competition to collect the first Sooty Tern egg of the season from the islet of Motu Nui, swim back to Rapa Nui and climb the sea cliff of Rano Kau to the clifftop village of Orongo.-Myth:In the...
("birdman") ritual: whichever
hopu (champion) could retrieve the first
manutara egg from
Motu NuiMotu Nui is the largest of three islets just south of Easter Island and is the most westerly place in Chile. All three islets have sea birds but Motu Nui was also an essential location for the Tangata manu cult which was the island religion between the moai era and the Christian times...
islet would become that year's
tangata manu; his
clanA clan is a group of people united by actual or perceived kinship and descent. Even if lineage details are unknown, clan members may be organized around a founding member or apical ancestor. The kinship-based bonds may be symbolical, whereby the clan shares a "stipulated" common ancestor that is a...
would receive prime access to resources, especially seabird eggs.
External links
- Army Ornithological Society