Great Bustard (Otis tarda)
Treecreeper (Certhia familiaris)
Heaviest bird in area. Stocky with well developed chest. Male 50% larger than female. Mostly unmistakable, and differs from all other bustards in area in all plumages by pale, grey head (yellowish grey in female), clearly paler than the rufous upperparts and lower neck. Male with thick neck, rufous chest and long moustache feathers. Female with more slender neck and duller colours. In flight the big white wing-patch is conspicuous. Base of hand pale with smooth transition to dark tips. Secondaries black. When displaying the male raises wings and body feathers to a "foam-bath" posture with head held low, like a white ball of feathers. Flight heavy but majestic. Shy and alert bird.
Sound:Mostly silent, especially away from breeding ground. Display call a short deep, hollow thud "omp", using resonating gular pouch. Most heard is a nasal grunt used in various types of excitement. Sometimes given in a flatulent series.
Excitement 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
CCCC-photo:cruzperezmanuel, Licence,Link.
CC-photo:Viskens Michel, Licence,Link.
CC-photo:Paul Dirksen, Licence,Link.
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