Scottish Crossbill (Loxia scotica)
Rook (Corvus frugilegus)
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
Image search Flickr NB! May give other species
CCCollage 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.
An all shiny black crow with diagnostic bare, pale grey base of bill, and "baggy trousers". Juveniles lacks bare bill base and are difficult to separate from Carrion Crow. Young Rooks however, has a steeper forehead and more conical bill with less curved culmen. Tail is more rounded and base of wings more narrow. Flight action includes less gliding than Carrion Crow, and individuals are more spread when a flock flies.
Sound:Makes similar caws as Carrion Crow, but is harsher, softer, flatter with less rolling r's. Also gives a varied song of soft gurgling and rattling sounds, interwoven with calls at breeding ground.
Contact call:
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CC