Scottish Crossbill (Loxia scotica)
Gyrfalcon (Falco rusticolus)
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.
Largest falcon. Heavily built. Grey upperparts and white, speckled underparts. Juveniles with browner plumage than adults, blue-grey legs and longitudinal streaking below. Diffuse moustache-stripe, and the whole head seems dark at distance, lacking a defined cap. Rounder and broader wings, longer tail and bulky belly distinguishes it from Peregrine. Underside of wings with dark coverts in contrast to pale base of flight-feathers. Extremely powerful, but slower flight action than Peregrine.
Sound:A coarse, drawn out, Peregrine-like "kaaawt", with emphasis on ending, is repeated in series. Much slower paced than in small falcons, and deeper and with different attack than in Peregrine. Also shorter, coarse warning-calls.
Alarm call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSounds:Recorded by Andrew Spencer,http://www.xeno-canto.org ,CC license