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Difference between revisions of "Caspian Tern" - BirdForum Opus

(Imp size. References updated)
(Image showing non-breeding plumage / gallery expanded)
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[[Image:Caspian Tern, Gambia, Phil Watson.jpg|thumb|550px|right|Photo by {{user|Phil+Watson|Phil Watson}}<br />Adult summer, [[Gambia]], April 2013]]
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[[Image:Caspian Tern, Gambia, Phil Watson.jpg|thumb|500px|right|Photo by {{user|Phil+Watson|Phil Watson}}<br />Adult summer, [[Gambia]], April 2013]]
 
;[[:Category:Hydroprogne|Hydroprogne]] caspia
 
;[[:Category:Hydroprogne|Hydroprogne]] caspia
 
''Sterna caspia''
 
''Sterna caspia''
 
==Identification==
 
==Identification==
 
Length 48–56 cm (19-22 in), wingspan 127-140 cm, weight 570-780 g. The largest tern, 50% heavier than the next largest ([[Royal Tern]] and [[Great Crested Tern]]). White head, neck, belly, tail; cap is black in breeding plumage, mottled with white in winter and in juvenile; pale grey back and upper wings, pale, dark tipped underwings, black legs, bill massive, red with a blackish smudge near the tip. Juveniles with mantle and wings mottled brown and tail blackish, subadults (1-2 years old) similar but with reduced mottling.
 
Length 48–56 cm (19-22 in), wingspan 127-140 cm, weight 570-780 g. The largest tern, 50% heavier than the next largest ([[Royal Tern]] and [[Great Crested Tern]]). White head, neck, belly, tail; cap is black in breeding plumage, mottled with white in winter and in juvenile; pale grey back and upper wings, pale, dark tipped underwings, black legs, bill massive, red with a blackish smudge near the tip. Juveniles with mantle and wings mottled brown and tail blackish, subadults (1-2 years old) similar but with reduced mottling.
[[Image:Caspian-tern-9012.jpg|thumb|350px|right|Juvenile in flight<br /> Photo by {{user|john-henry|john-henry}}<br />[[Portugal]], November 2008 ]]
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[[Image:caspian-tern_alok.JPG|thumb|350px|right|Non-breeding adult<br /> Photo by {{user|aloktewari|Alok Tewari}}<br />Jamnagar, Coastal Gujarat, [[India]], January-2018 ]]
 
==Distribution==
 
==Distribution==
 
Widespread but patchy breeding distribution in temperate and subtropical regions of [[Europe]] (north to 66°N in the Baltic Sea), [[Asia]], [[Africa]], [[North America]] (north to 62°N in the Great Slave Lake in Northwest Territories), [[Australia]] and [[New Zealand]]. Migratory in the temperate Northern Hemisphere, wintering south to the tropics (including the [[West Indies]] and northern [[South America]], where it does not breed); resident or dispersive in the subtropics and the temperate Southern Hemisphere.
 
Widespread but patchy breeding distribution in temperate and subtropical regions of [[Europe]] (north to 66°N in the Baltic Sea), [[Asia]], [[Africa]], [[North America]] (north to 62°N in the Great Slave Lake in Northwest Territories), [[Australia]] and [[New Zealand]]. Migratory in the temperate Northern Hemisphere, wintering south to the tropics (including the [[West Indies]] and northern [[South America]], where it does not breed); resident or dispersive in the subtropics and the temperate Southern Hemisphere.
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Image:Caspian_Tern.jpg|Subadult<br />Photo by {{user|avesdigital|avesdigital}}<br />[[Tarifa]], [[Spain]]<br />Click on image to view larger version
 
Image:Caspian_Tern.jpg|Subadult<br />Photo by {{user|avesdigital|avesdigital}}<br />[[Tarifa]], [[Spain]]<br />Click on image to view larger version
 
Image:Young larid.jpg|Juvenile<br /> Photo by {{user|blubird|blubird}}<br />Las Gallinas, [[California]], July 2008 <br />Click on image to view larger version
 
Image:Young larid.jpg|Juvenile<br /> Photo by {{user|blubird|blubird}}<br />Las Gallinas, [[California]], July 2008 <br />Click on image to view larger version
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Image:Caspian-tern-9012.jpg|Juvenile in flight<br /> Photo by {{user|john-henry|john-henry}}<br />[[Portugal]], Nov-2008 <br />Click on image to view larger version
 
</gallery>
 
</gallery>
 
==Behaviour==
 
==Behaviour==

Revision as of 02:18, 27 January 2018

Photo by Phil Watson
Adult summer, Gambia, April 2013
Hydroprogne caspia

Sterna caspia

Identification

Length 48–56 cm (19-22 in), wingspan 127-140 cm, weight 570-780 g. The largest tern, 50% heavier than the next largest (Royal Tern and Great Crested Tern). White head, neck, belly, tail; cap is black in breeding plumage, mottled with white in winter and in juvenile; pale grey back and upper wings, pale, dark tipped underwings, black legs, bill massive, red with a blackish smudge near the tip. Juveniles with mantle and wings mottled brown and tail blackish, subadults (1-2 years old) similar but with reduced mottling.

Non-breeding adult
Photo by Alok Tewari
Jamnagar, Coastal Gujarat, India, January-2018

Distribution

Widespread but patchy breeding distribution in temperate and subtropical regions of Europe (north to 66°N in the Baltic Sea), Asia, Africa, North America (north to 62°N in the Great Slave Lake in Northwest Territories), Australia and New Zealand. Migratory in the temperate Northern Hemisphere, wintering south to the tropics (including the West Indies and northern South America, where it does not breed); resident or dispersive in the subtropics and the temperate Southern Hemisphere.

There are records most years for the British Isles.

Taxonomy

This is a monotypic species[1], in spite of its near-cosmopolitan range. Some authorities formerly recognised two or three subspecies, with nominate H. c. caspia in the Old World, H. c. imperator in the New World, and H. c. strenua in Australasia.

It was in the past (and is still by some authorities) included in the genus Sterna.

Habitat

Large lakes (fresh or salt water) and shallow, sheltered sea coasts; avoids exposed and deep-water ocean coasts. Breeds on sandy coasts and islands.

Behaviour

Diet

The diet includes fish, insects, eggs and young birds.

Breeding

They are ground nesters, colonially and singly; 1-3 pale blue green eggs, heavily spotted brown, are laid in a bare scrape.

Vocalisation

The call is a loud croak.

<flashmp3>Sterna caspia (song).mp3</flashmp3>
Listen in an external program

References

  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2016. The eBird/Clements checklist of birds of the world: v2016, with updates to August 2016. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
  2. Wikipedia
  3. Collins Field Guide 5th Edition
  4. Collins Bird Guide ISBN 0 00 219728 6

Recommended Citation

External Links


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