Appearance:

Differs from Common and Arctic Tern by; noticably shorter wings, longer streamers, much paler grey upperparts, pure white underparts (faint rosy wash not very conspicuous), black bill (red base in breeding birds), dark outer primaries and no dark edge to inner primaries. Amount of red in bill increases as breeding season progresses, but also varies geographically. Wingbeats shallower and much quicker than in Common and Arctic Tern. Fishes with characteristic diagonal dives. Despite the long streamers, the birds appear short-tailed in flight, but head and bill are long and slender. The pale plumage, dark bill and giss recalls a small Sandwich Tern. Adult winter plumage with all dark bill and white forehead. Juveniles resembles juvenile Sandwich Terns, with more complete dark cap than Arctic and Common, and much more contrasting markings on back (especially to wings).

Sound:

Extremely harsh calls. Like mix of Caspian and Arctic Tern. Very hard and raspy "kreeeet", harder and higher pitched than Caspian Tern, but equally harsh. Other calls include more Arctic/Common tern-like short "kek", and similar.

Contact call:

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

CC

CC-photo:USFWS/Southeast, Licence,Link.

CC-photo:Werner Witte, Licence,Link.

CC-photo:Anita363, Licence,Link.

CC-photo:Mike Prince, Licence,Link.

Appearance:

Large and robust warbler with plain plumage, except for the characteristic cap (black in males, rufous in females and juveniles). Upperparts greyish brown and underparts pale grey. Vent white. No white in tail, as opposed to all other black-capped Sylvias in the region. Easily confused with Garden Warbler if the cap is not seen.

Sound:

Song pleasing, varied and loud. Sometimes very similar to Garden Warbler. A typical phrase starts with soft, staccato chattering and mimicry, which after a few seconds changes to a much louder, pure and resonant stream of notes for about 3-5 seconds. No fixed motif, but may end phrases with recurring notes. Often deviates from the characteristic type of song, and identification from song alone may be impossible. May sing first part of song for extended periods without ever reaching the characteristic ending. Alarm call a hard "check", similar to Lesser White-throat. Sometimes with an additional hoarse and nasal "cherrrr".

Alarm call, song:

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