Overview

Caspian Tern: This large stocky tern has pale grey upperparts and white underparts. The cap is black and may appear weakly crested. The large bill is coral-red, the undersides of the primaries are grey, a short white tail is slightly forked, and the legs are black. The flight is strong, swift and graceful. It hovers above water before diving and mainly feeds on fish. The sexes are similar.

Caspian Tern: Breeds in scattered colonies in Eurasia, Africa, and North America. Winters in areas of Africa, India, China, Mexico, Florida, and the Caribbean. Occurs year-round in Australia, New Zealand, and parts of Africa and Asia. Preferred habitats include sandy or pebbly shores of lakes and large rivers and along coasts. Rare vagrant to the UK & Ireland.

Voice Text

"Kaark" and "ka-arr"

• A group of terns are collectively known as a "ternery" or a "U" of terns.
• The Caspian Tern aggressively defends its breeding colony. It will pursue, attack, and chase potential predatory birds and humans.
• Young Caspian Terns have a difficult time learning to catch fish. They stay with their parents for long periods of time, and are fed by them even on the wintering grounds.

• Arctic Tern
• Common Tern

Terns (Sternidae)

ORDER

The nineteen families in the taxonomic order CHARADRIIFORMES (pronounced kah-RAH-dree-ih-FOR-meez) include waterbirds such as oystercatchers, avocets, gulls, and terns.

FAMILY TAXONOMY

Distributed worldwide (including the polar regions), the family Sternidae (pronounced STURN-uh-dee) encompasses forty-four species of terns in nine genera (IOC World Bird List, version 2.3). It should be noted that terns were, until recently, included in the same family as gulls (the Laridae).

EUROPE

In Europe twenty-two species of Sternidae in eight genera have occurred. Members of this bird family include the “marsh terns" of the Chlidonias genus (Black, White-winged Black, and Whiskered Terns), and the Arctic Tern.

KNOWN FOR

Members of the Sternidae are known for their elegant appearance, graceful flight, and association with aquatic habitats.

PHYSICAL

Terns are web-footed birds with long, rather slim wings. Most species have thin, dagger-like bills (Gull-billed and Caspian Terns being notable exceptions), and notched or forked tails. They range in size from that of a Starling (the Little Tern) to a bit larger than a Common Gull (the Caspian Tern).

COLORATION

Adult terns are mostly pale-coloured birds plumaged in grey and white with black on the crown and in the wingtips. Marsh terns and noddies are generally darker in coloration. Other colours are limited to red and yellow (in the bills and feet) and rose-coloured hues in the plumage of the Roseate Tern.

GEOGRAPHIC HABITAT

The Sternidae occur near fresh and salt water throughout Europe but are most common near large bodies of water.

MIGRATION

European tern species are highly migratory and for the most part spend the winter in subtropical and tropical coasts and waterways of Africa.

HABITS

The Sternidae are social, rather vocal birds that nest in colonies in marshes, on isolated beaches, and rocky islets. Most species forage for small fish by diving into the water although some terns will also hawk insects from the air during flight.

CONSERVATION

Several tern species have declined due to disturbance at their nesting colonies, pollution of waterways, and destruction of their marsh, riverine, and coastal habitats. Populations of the Little Tern (and the related Least Tern of North America) have been especially hard hit by these factors and have thus become species of conservation concern in many areas.

INTERESTING FACTS

The Arctic Tern migrates more than twenty thousand miles each year on a round trip journey between the Arctic and Antarctic. Some populations of this species actually do a circle of the Atlantic by flying to northern Europe, heading south along the African coast to Antarctica and then following the American coastlines north.

Artist

Chris Vest