Little Tern
Encyclopedia
The Little Tern, Sternula albifrons or Sterna albifrons, is a seabird
of the tern
family Sternidae. It was formerly placed into the genus Sterna, which now is restricted to the large white terns (Bridge et al., 2005). The former North America
n (S. a. antillarum) and Red Sea
S. a. saundersi subspecies
are now considered to be separate species, the Least Tern (Sternula antillarum) and Saunders's Tern
(Sternula saundersi).
This bird
breeds on the coasts and inland waterways of temperate and tropical Europe
and Asia
. It is strongly migratory
, wintering in the subtropical and tropical oceans as far south as South Africa
and Australia
.
There are three subspecies, the nominate albifrons occurring in Europe to North Africa and western Asia; guineae of western and central Africa; and sinensis of East Asia and the north and east coasts of Australia (Higgins and Davies, 1996).
The Little Tern breeds in colonies on gravel or shingle coasts and islands. It lays two to four eggs on the ground. Like all white terns, it is defensive of its nest and young and will attack intruders.
Like most other white terns, the Little Tern feeds by plunge-diving for fish, usually from saline environments. The offering of fish by the male to the female is part of the courtship display.
This is a small tern, 21–25 cm long with a 41–47 cm wingspan. It is not likely to be confused with other species, apart from Fairy Tern and Saunders's Tern, because of its size and white forehead in breeding plumage. Its thin sharp bill is yellow with a black tip and its legs are also yellow. In winter, the forehead is more extensively white, the bill is black and the legs duller. The call is a loud and distinctive creaking noise.
The loss of inland populations has been even more severe, since due to dams, river regulation and sediment extraction it has lost most of its former habitats. The Little Tern population has declined or become extinct in many European countries, and former breeding places on large rivers like the Danube
, Elbe
and Rhine ceased. Nowadays, only few river systems in Europe possess suitable habitats; the Loire/Allier in France
, the Vistula/Odra in Poland
, the Po/Ticino in Italy
, the Daugava in Latvia
, the Nemunas in Lithuania
, the Sava in Croatia
and the Drava in Hungary
and Croatia. The status of the Little Tern on the rivers Tagus and lower Danube is uncertain.
The Drava population is one of the most threatened. Old fashioned water management practices, including river regulation and sediment extraction, endanger the remaining pairs. Only 15 pairs still breed on extensive sand or gravel banks along the border between Hungary and Croatia. The WWF and its partners are involved in working for the protection of this bird and this unique European river ecosystem. The Little Tern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA
) applies.
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...
of the tern
Tern
Terns 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...
family Sternidae. It was formerly placed into the genus Sterna, which now is restricted to the large white terns (Bridge et al., 2005). The former North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
n (S. a. antillarum) and Red Sea
Red Sea
The 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...
S. a. saundersi subspecies
Subspecies
Subspecies 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...
are now considered to be separate species, the Least Tern (Sternula antillarum) and Saunders's Tern
Saunders's Tern
The Saunders's Tern is a species of tern in the Sternidae family.It is found in Bahrain, Iran, Israel, Kenya, Madagascar, Pakistan, Oman, Saudi Arabia, Tanzania, United Arab Emirates, and Yemen.-References:...
(Sternula saundersi).
This bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
breeds on the coasts and inland waterways of temperate and tropical Europe
Europe
Europe 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...
and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. It is strongly migratory
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...
, wintering in the subtropical and tropical oceans as far south as South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and 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...
.
There are three subspecies, the nominate albifrons occurring in Europe to North Africa and western Asia; guineae of western and central Africa; and sinensis of East Asia and the north and east coasts of Australia (Higgins and Davies, 1996).
The Little Tern breeds in colonies on gravel or shingle coasts and islands. It lays two to four eggs on the ground. Like all white terns, it is defensive of its nest and young and will attack intruders.
Like most other white terns, the Little Tern feeds by plunge-diving for fish, usually from saline environments. The offering of fish by the male to the female is part of the courtship display.
This is a small tern, 21–25 cm long with a 41–47 cm wingspan. It is not likely to be confused with other species, apart from Fairy Tern and Saunders's Tern, because of its size and white forehead in breeding plumage. Its thin sharp bill is yellow with a black tip and its legs are also yellow. In winter, the forehead is more extensively white, the bill is black and the legs duller. The call is a loud and distinctive creaking noise.
Little Tern on European rivers
At the beginning of the 19th century the Little Tern was a common bird of European shores, rivers and wetlands, but in the 20th century populations of coastal areas decreased because of habitat loss, pollution and human disturbance.The loss of inland populations has been even more severe, since due to dams, river regulation and sediment extraction it has lost most of its former habitats. The Little Tern population has declined or become extinct in many European countries, and former breeding places on large rivers like the Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....
, Elbe
Elbe
The Elbe is one of the major rivers of Central Europe. It rises in the Krkonoše Mountains of the northwestern Czech Republic before traversing much of Bohemia , then Germany and flowing into the North Sea at Cuxhaven, 110 km northwest of Hamburg...
and Rhine ceased. Nowadays, only few river systems in Europe possess suitable habitats; the Loire/Allier in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, the Vistula/Odra in Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
, the Po/Ticino in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, the Daugava in Latvia
Latvia
Latvia , officially the Republic of Latvia , is a country in the Baltic region of Northern Europe. It is bordered to the north by Estonia , to the south by Lithuania , to the east by the Russian Federation , to the southeast by Belarus and shares maritime borders to the west with Sweden...
, the Nemunas in Lithuania
Lithuania
Lithuania , officially the Republic of Lithuania is a country in Northern Europe, the biggest of the three Baltic states. It is situated along the southeastern shore of the Baltic Sea, whereby to the west lie Sweden and Denmark...
, the Sava in Croatia
Croatia
Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...
and the Drava in Hungary
Hungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...
and Croatia. The status of the Little Tern on the rivers Tagus and lower Danube is uncertain.
The Drava population is one of the most threatened. Old fashioned water management practices, including river regulation and sediment extraction, endanger the remaining pairs. Only 15 pairs still breed on extensive sand or gravel banks along the border between Hungary and Croatia. The WWF and its partners are involved in working for the protection of this bird and this unique European river ecosystem. The Little Tern is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA
AEWA
The Agreement on the Conservation of African-Eurasian Migratory Waterbirds is the largest of its kind developed so far under the Bonn Convention. It was concluded on 16 June 1995 at The Hague, the Netherlands and entered into force on 1 November 1999 after the required number of at least fourteen...
) applies.