Parasitic Jaeger (Stercorarius parasiticus)
Treecreeper (Certhia familiaris)
Dark, pale and intermediate morphs. Pale birds more common in northern parts of species range, darker morphs more common further south. Elongated middle tail feathers (projection comprising about half the total tail length), but not as long as in adult Long-tailed skua. White patches at base of primaries, both on upper and underside of wings. Dark morph chocolate brown with darker hood. Pale morph with white throat and belly and incomplete breast band. Relatively marked transition from pale belly to dark vent (as opposed to Long-tailed). Size close to Common Gull. Flight powerful, elegant and falcon-like. Juveniles with short but pointed middle tail-feathers. Confusion with other juvenile skuas very likely. Differs from Long-tailed in prominent white base of most primaries on upper side of wing (not just the first few feathers). Lacks the double white patch of Pomarine Skua's underwing, and shows less contrast between back and rump. Wings broader than Long-tailed but narrower than Pomarine. Approximately equal to distance from wing rear edge to tail-tip (projections excluded).
Sound:Mostly heard at breeding ground. Most characteristic call is a mewing, kittiwake-like "aeeeee-ah". First syllable drawn-out and rising in pitch, and followed by a deeper conclusive second syllable "ah". Lacks the introductory double accent of Kittiwakes ("kitti-wake").
Alarm call/flight 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
CCSounds:Recorded by Fernand Deroussen,http://www.xeno-canto.org ,CC license
Unmistakable, except in areas where it coexists with Short-toed Treecreeper. Differs from said species in pure white flanks (sub-species macrodactyla has faintly buff flanks but not as marked as in Short-toed), shorter and only moderately curved bill, hind-claw as long as hind-toe and "notched" wing-bar (uneven "steps"). Tips of primaries with buffish/white tips/fringes extending along inner web. Mostly distinguished from Short-toed by call, and identification exclusively by plumage characters difficult in areas where both species occur.
Sound:Contact call a drawn, high-pitched "tzreeee". Similar to Goldcrest in timbre, but of longer duration with a vibrating and slightly rolling tone. Generally repeated in evenly paced, slow series (unlike Goldcrest). Song a short, continuous three-part phrase. Each phrase starts with a few contact call-like notes followed by a Willow Warbler-like descending part, which then jumps to a few descending high notes to form a marked conclusion. Note that "mixed singers" are not uncommon in areas where both species of treecreepers occur.
Song:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CC