Birds in Bulgaria

L 22-27 cm, WS 50-62 cm. Breeds in dense forests with small bogs and glades. Fairly common in N Europe; about 50 records in Britain. Mainly sedentary, but in some autumns many move south, possibly predominantly females and young. Strictly nocturnal, difficult to see other than in vicinity of nest. Food mainly voles. Nests in tree-hole (old nest of Black Woodpecker) or box.
IDENTIFICATION: Medium-small (about the same size as Little Owl), large-headed (flattish crown). Medium-sized eyes yellow, facial expression ‘astonished’. Upperparts brown, with whitish spots and diffuse blotches on shoulders; underparts whitish, diffusely blotched brownish. Wings rounded, flight rather direct with series of quick wingbeats and brief straight glides. Greatest risk of confusion Pygmy Owl (small, same range and habitat), but this is only the size of a Starling, has proportionately smaller head, has different, ‘stern’ facial expression, shows tendency to bounding flight, and has proportionately shorter wings; also, Pygmy often perches in treetops, whereas Tengmalm’s prefers canopy. - Juvenile: Mainly chocolate-brown, with variable amount of white on face.
VOICE: Rather vocal. Commonest call squirrel-like ‘chiak’. Song a rapid series of deep whistling notes (5-8; when excited, drawn out to much longer series), initially slightly rising in pitch and pace, surprisingly loud (audible to well over 3 km on calm nights), ‘pu-po-po-po-po-po’; pitch and speed vary somewhat; possible to mimic (lowest possible whistling). Begging-call of young a thin, abrupt ‘ksi!’.