Treecreeper (Certhia familiaris)
Long-tailed Jaeger (Stercorarius longicaudus)
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
CCBreeding plumaged adults with streamers unmistakable (streamers comprising two thirds of total tail length). Adult plumage shows less variation than in other skuas. No hint of breast band, and transition between pale belly and darker vent very diffuse. No white patches at base of primaries of underwing in adults. Juveniles easily confused with juvenile Arctic Skua, but are more slender. Wings narrower and primaries and tail longer. Juvenile Arctic Skua shows white patches at base of primaries on both sides of wings, juvenile Long-tailed only on underwing, and on first few primaries of upper. Barred rump and tail coverts in juveniles. Flight elegant and buoyant.
Sound:Calls sharp and less full-bodied than Arctic Skua, and not so mewing. Short, double-accented "kew-wev" or short "kerk" in agitation. Also a long drawn-out "keeeeaah", resembling both Arctic Skua and Common Gull.
Alarm/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 Andrew Spencer,http://www.xeno-canto.org ,CC license