Appearance:

Only in the UK. Similar to Red and Parrot Crossbill in plumage. Bill size possibly the only visual identification clue, but even this overlaps with the other two species. Bill is usually deeper and heavier than Red Crossbill. Certain separation from Parrot Crossbill in the field by visual characters alone, probably not possible. Species status mainly upheld by isolated breeding population and differences in excitement calls from other crossbills. Calls probably play an important role in maintaining the reproduction barrier between Crossbill populations with different bill-size. See Birdlife link below for more info.

Sound:

Calls very similar to Parrot Crossbill, and sonogram analysis may be needed for certain identification. Flight and excitement calls show most unique quality. Sonogram image above by Ron Summers (used with permission). A detailed article about crossbill calls can be found here.

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

CC

Collage photo By Richard Crossley (The Crossley ID Guide Britain and Ireland) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons.

Appearance:

Forked and fairly long tail. Clearly bigger than Storm Petrel, with more slender appearance and longer wings. Generally not as black, and shows brownish tone to plumage. The white rump patch is oval, has a weak grey center stripe, and does not reach as far down on the sides as in Storm Petrel. Light grey upper greater coverts form a wing-band. Underside of wings all dark. Flight pattern variable, with frequent changes in direction and speed. Sometimes glides like a shearwater but at other times shows surprisingly deep wing-beats. Does not patter surface, but will rest on water. Visits breeding ground only at night, and is usually only seen after storms.

Sound:

Only calls at breeding ground. A series of accentuated cooing, interrupted by a squeaky "inbreath" and a loud, absurd, fanfare-like "kaaa-ka-ka-kaaa-ka".

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

CC

CC-sound:Steph, Licence,Link.