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:

Differs from House Sparrow by warm brown crown, white cheeks, white (incomplete) collar and diagnostic, black cheek patch. From Spanish Sparrow by cheek patch, and lack of black breast markings. Brown and streaked rump. The black bib does not expand towards the chest. Head profile rounder and neater than House Sparrow, with slightly smaller bill. Identification by profile alone is possible with practice. Sexes and ages alike.

Sound:

Distinct, high-pitched and explosive contact-call; "che-witt" typically given in flight. Second syllable rising rapidly in pitch. Most other sounds similar to House Sparrow, and may be difficult to identify. Chattering sounds are generally harder, and song slightly higher pitched than House Sparrow.

Call and 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

CC-sound:Peter Boesman, Licence,Link.