The whiskered tern (''Chlidonias hybrida'') is a
tern
Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of e ...
in the family
Laridae
Laridae is a family of seabirds in the order Charadriiformes that includes the gulls, terns, skimmers and kittiwakes. It includes around 100 species arranged into 22 genera. They are an adaptable group of mostly aerial birds found worldwide. ...
. The genus name is from
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
''khelidonios'', "swallow-like", from ''khelidon'', "
swallow
The swallows, martins, and saw-wings, or Hirundinidae, are a family of passerine songbirds found around the world on all continents, including occasionally in Antarctica. Highly adapted to aerial feeding, they have a distinctive appearance. The ...
". The specific ''hybridus'' is
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
for ''hybrid'';
Peter Simon Pallas
Peter Simon Pallas FRS FRSE (22 September 1741 – 8 September 1811) was a Prussian zoologist and botanist who worked in Russia between 1767 and 1810.
Life and work
Peter Simon Pallas was born in Berlin, the son of Professor of Surgery ...
thought it might be a hybrid of
white-winged black tern and
common tern
The common tern (''Sterna hirundo'') is a seabird in the family Laridae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migrator ...
, writing "''Sterna fissipes
'Chlidonias leucopterus''et Hirundine
'Sterna hirundo''natam''”.
This
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 lightweig ...
has a number of geographical races, differing mainly in size and minor plumage details.
''C. h. hybrida'' breeds in warmer parts of
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
and the
Palearctic (northwestern Africa and central and southern Europe to southeastern Siberia, eastern China and south to Pakistan and northern India). The smaller-billed and darker ''C. h. delalandii'' is found in east and south
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, and the paler ''C. h. javanicus'' from
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...
to
Australia.
The tropical forms are resident, but European and Asian birds
winter
Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultur ...
south to Africa and the
Indian Subcontinent
The Indian subcontinent is a list of the physiographic regions of the world, physiographical region in United Nations geoscheme for Asia#Southern Asia, Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian O ...
. A tagged whiskered tern was spotted at Manakudi Bird Sanctuary,
Kanniyakumari District
Kanniyakumari district is one of the 38 districts in Tamil Nadu state and the southernmost district in mainland India. It stands second in terms of population density among the districts of Tamil Nadu. It is also the richest district in Tamil Na ...
of
Tamil Nadu
Tamil Nadu (; , TN) is a state in southern India. It is the tenth largest Indian state by area and the sixth largest by population. Its capital and largest city is Chennai. Tamil Nadu is the home of the Tamil people, whose Tamil language ...
,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
in the month of April 2021.
[Two Tagged migratory birds spotted in salt pans in Manakudy bird reserve, The Hindu, Thiruchirappalli, Tamil Nadu Edition, India, pp4, 12.04.2021. thehindu.com]
This species breeds in colonies on inland marshes, sometimes amongst
black-headed gull
The black-headed gull (''Chroicocephalus ridibundus'') is a small gull that breeds in much of the Palearctic including Europe and also in coastal eastern Canada. Most of the population is migratory and winters further south, but some birds r ...
s, which provide some protection. The scientific name arises from the fact that this, the largest
marsh tern, show similarities in appearance to both the white ''Sterna'' terns and to
black tern
The black tern (''Chlidonias niger'') is a small tern generally found in or near inland water in Europe, Western Asia and North America. As its name suggests, it has predominantly dark plumage. In some lights it can appear blue in the breeding se ...
.
Description
The size, black cap, strong bill (29–34 mm in males, 25–27 mm and stubbier in females, with a pronounced gonys) and more positive flight recall common or
Arctic tern, but the short, forked-looking tail and dark grey breeding plumage above and below are typically marsh tern characteristics. The summer adult has white cheeks and red legs and bill. The crown is flecked with white in the juvenile, and the hindcrown is more uniformly blackish, though in the winter adult this too is flecked with white. The black ear-coverts are joined to the black of the hindcrown, and the space above is mottled with white, causing the black to appear as a C-shaped band. The sides of the neck are white; this sometimes continues across the nape. The collar is less sharply defined. All through the year the rump is pale grey. In the juvenile, the mantle (279 mm) has a variegated pattern. The feathers of the back and scapulars are dark brown, with prominent broad buff edgings and often subterminal buff bars or centers. There is usually an admixture of new gray feathers, especially on the mantle, quite early in the fall. The mantle is silvery-gray in the adult.
The call is a characteristic ''krekk''.
In winter, the forehead becomes white and the body plumage a much paler grey. Juvenile whiskered terns have a ginger scaly back, and otherwise look much like winter adults. The first winter plumage is intermediate between juvenile and adult winter, with patchy ginger on the back.
The whiskered tern eats small fish, amphibians, insects and crustaceans.
References
External links
Whiskered tern in The Atlas of Southern African Birds
{{Taxonbar, from=Q233616
whiskered tern
Birds of Africa
Birds of Eurasia
whiskered tern
Taxa named by Peter Simon Pallas