Saunders's tern (''Sternula saundersi''), sometimes known as the Black-Shafted tern, is a species of

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

in the family Laridae. It is sparsely resident along the shores of the north-western

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

(namely southern

Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...

Arabian peninsula The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate ...

Socotra Socotra or Soqotra (; ar, سُقُطْرَىٰ ; so, Suqadara) is an island of the Republic of Yemen in the Indian Ocean, under the ''de facto'' control of the UAE-backed Southern Transitional Council, a secessionist participant in Yemen’s ...

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

Andaman and Nicobar Islands The Andaman and Nicobar Islands is a union territory of India consisting of 572 islands, of which 37 are inhabited, at the junction of the Bay of Bengal and the Andaman Sea. The territory is about north of Aceh in Indonesia and separated f ...

and northern

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

). It is a close relative of the Little Tern, Least Tern,

Yellow-billed tern The yellow-billed tern (''Sternula superciliaris'') is a small seabird found in South America. It is a species of tern in the family Laridae. It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Panama, Paraguay, ...

, and

Peruvian tern The Peruvian tern (''Sternula lorata'') is a species of tern in the family Laridae. Found in northern Chile, Ecuador, and Peru, its natural habitats are hot deserts, sandy shores, and coastal saline lagoons. It is threatened by habitat loss. In ...

. In non-breeding plumages, the Saunder's Tern and the Little Tern may be almost indistinguishable. The two have been considered by some to be conspecific.

Description

Saunders's tern shares many of the features of its close relative, the Little Tern, including a white body, a black-tipped yellow bill, and a black cap with a white forehead patch. In its breeding

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

, it distinguishes itself with a straight-bordered forehead patch, possessing more black outer

primaries Primary elections, or direct primary are a voting process by which voters can indicate their preference for their party's candidate, or a candidate in general, in an upcoming general election, local election, or by-election. Depending on the c ...

, and duskier colored legs and feet in comparison to the bright yellow legs of the Little Tern. In non-breeding plumage, the two are very similar. Saunders's tern is 20–28 cm (8-11 in) long, weighs 40-45 grams, and possesses a

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan of ...

of 50-55 cm(20-21 in). It has an average wing length of 16.6 cm(6.5 in), an average

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

length of 2.8 cm(1.1 in), and a tail fork depth of about 2.8 cm(1.1 in) on average.

Taxonomy

Saunders's tern was first described in 1877 by British

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

and

ornithologist Ornithology is a branch of zoology that concerns the "methodological study and consequent knowledge of birds with all that relates to them." Several aspects of ornithology differ from related disciplines, due partly to the high visibility and th ...

Allan Octavian Hume during his stay in

British India The provinces of India, earlier presidencies of British India and still earlier, presidency towns, were the administrative divisions of British governance on the Indian subcontinent. Collectively, they have been called British India. In one ...

as part of the

Imperial Civil Service The Indian Civil Service (ICS), officially known as the Imperial Civil Service, was the higher civil service of the British Empire in India during British rule in the period between 1858 and 1947. Its members ruled over more than 300 million p ...

. It was originally given the name Black-Shafted ternlet (Sterna saundersi) by Hume, which was later changed to its present common name. It is considered by some to be a subspecies of Sternula albifrons, potentially of a larger species group, or otherwise conspecific.

Behavior

Feeding

The majority of the Saunders's Tern's diet consists of various

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

animals, including small fish,

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

, and

mollusks Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

. It will also eat several varieties of insects. An individual will hover above the water for a sizable amount of time, before making a

plunge dive Seabirds (also known as marine birds) are birds that are adaptation, adapted to life within the marine (ocean), marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent ev ...

to catch fish.

References

Saunders's tern Saunders's tern (''Sternula saundersi''), sometimes known as the Black-Shafted tern, is a species of bird in the family Laridae. It is sparsely resident along the shores of the north-western Indian Ocean (namely southern Somalia, Arabian peninsul ...

Birds of Western Asia Birds of Pakistan Birds of Sri Lanka

Taxonomy articles created by Polbot {{charadriiformes-stub