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:

Olive green upperparts, yellowish chest with gradual transition to off-white belly. Very similar to Willow Warbler, and most field characters are subtle and often hard to see. Distinguished by (usually) black, or dark-brown legs, only faint dark framing to ear-coverts, less marked supercilium. Shorter primary projection (1/2 to 2/3'rds the lenght of tertials), with regularly spaced tips (visible when wing folded). Wings more fan-shaped and less pointed than in Willow Warbler. Juveniles much less yellow below than in W.Warbler. Generally leaves a duller and greyer impression than W. Warbler, but plumage very variable. Frequently flicks tail, even sideways. Generally also more active when moving among the foliage.

Sound:

Contact/alarm call a soft, plaintive ascending "hooeet". Similar to W.Warbler, but shorter with a monosyllabic feel. Song a very distinct: "chiff-chaff-chiff-chiff-chaff-chiff", in a regular clock-like rhythm. Each syllable at seemingly random pitch, but no large intervals tonally. Sometimes "get stuck" at one note.

Contact 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