Birds in Bulgaria

L 12½-13½ cm. Breeds in habitats with low, thick vegetation, often in tussocky marshland beside lakes (where tussocks tallest), in young conifer plantations or clear-felled areas, among tall grass and herbage with scattered bushes, often along riversides. Summer visitor (in Britain & Ireland May-Jul), winters so far as known in tropical Africa. Except when singing, very hard to see; keeps well concealed and creeps in grass like a mouse. Nests low in dense vegetation.
IDENTIFICATION: A Sedge Warbler-sized, grey-brown bird with no striking plumage features. Dark-spotted above on olive-tinged grey-brown ground; off-white or sometimes warmer buffy yellow-white below, unspotted or with variable amount of small dark spots on throat and upper breast (many have a few spots only; rarely, showing dense heavy spotting, and in addition some diffuse streaking on flanks, producing similarity to Lanceolated Warbler; cf. latter). Distinguished from Sedge Warbler by: lack of prominent, whitish supercilium (has just faint suggestion); off-white, diffusely streaked undertail-coverts; olive-tinged grey-brown and weakly dark-spotted rump not contrasting appreciably with back; evenly fine-streaked crown without darker sides. Legs pinkish, bill rather dark. Tertials dark, with bases broadly and diffusely edged brown. Sexes alike. In autumn, juveniles often yellowish below while adults are off-white.
VOICE: Call a sharp, piercing ‘psvitt’. Song peculiar, an insect-like, mechanical, dry ringing or whirring reel, ‘sir’r’r’r’r’r’r’r’r’r’r…’, heard mostly from late dusk and at night, and which continues for a minute or more. The sound may be likened to an alarm clock with muffled clapper; volume varies somewhat depending on how bird turns its head. (Three congeners have similar song: Lanceolated (see below), Savi’s (see p. 294) and River (see p. 294) Warblers.