From Opus

Revision as of 22:33, 6 December 2008

Photo by Carpie
Location: Terschelling, Holland.

Sterna hirundo

Identification

Medium-sized tern
L. 34-37 cm
Ws. 70-80 cm

• Thin, sharp bill
  • Red with dark tip
• Red legs
  • Relatively long
• Wingtips extend to tail

Similar Species

Most readily confused within its range with the similar Arctic Tern and Roseate Tern.

Both Arctic and Roseate Terns have wingtips that don't reach tailtip on standing bird. Roseate tern is paler with shorter wings.

Distribution

This bird has a circumpolar distribution breeding in temperate and sub-arctic regions of Europe, Asia and east and central North America. It is strongly migratory, wintering in the subtropical and tropical oceans. It is sometimes known as the sea swallow.

Taxonomy

A seabird of the tern family Sternidae.

Habitat

This species breeds in colonies on coasts and islands and often inland on suitable freshwater lakes. This latter practice is assisted by the provision of floating "tern rafts" to give a safe breeding area.

Behaviour

Diet

Like all Sterna terns, the Common Tern feeds by plunge-diving for fish, from either the sea or freshwater lakes and large rivers. It usually dives directly, and not from the "stepped-hover" favoured by Arctic Tern. The offering of fish by the male to the female is part of the courtship display. Common Terns are known to reach an age of 23 years or more on occasion

Breeding

Lays two to four eggs. Like many white terns, it is very defensive of its nest and young and will attack humans and other large predators, but unlike the more aggressive Arctic Tern rarely hits the intruder, usually swerving off at the last moment.

Vocalisation

External Links