Certhia familiaris
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.
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.
Xeno-canto: map
Birdlife ecology
