Appearance:

Unmistakable. Extremely long tail and short wings. Fluttering and undulating flight, with peculiar silhouette like a small ball with a long tail. Head of Northern Europe sub.sp. completely white. Continental and British birds with broad, dark supercilium. Juveniles head dark with white crown and throat. Always active and on the move in small groups.

Sound:

Song: Rapid, continuous, randomly composed sequence of bubbling,chirping sounds. Call: quite short, chirping, twittering "tzzirrret tzirrrret". Often starting at high pitch and rapidly falling, or just flat. Also a thin, slightly falling "zi zi ziii".

Contact call:

Distribution:

Xeno-canto: map

Ecology:

Birdlife ecology

Links:

Observation.org Latest observations

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

Appearance:

Differs from Common Tern in shorter head, and blood-red bill. Legs shorter, but tail streamers longer (extends well past wings in sitting birds). Underparts of primaries with sharply bordered dark trailing edge (diffusely bordered in Common Tern). Both primaries and secondaries transparent to sunlight. Crest less apparent than in Common Tern and underside greyer. Cheeks white just below the black cap, often in contrast to grey lower cheeks. Juveniles lacks buff coloured back.

Sound:

Similar to Common Tern but higher pitched. Typical call a series of high pitched "tip-tip-tip", and longer, ringing, high-pitched "kriiiiii" calls. The drawn out "kree-aaahh" call falls less distinctly in pitch than Common Tern.

Calls:

Distribution:

Wikipedia: map (se also Xeno-canto below)

Ecology:

Birdlife ecology

Links:

Observation.org Latest observations

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

CC-sound:Stein Ø. Nilsen, Licence,Link.