Birds in Bulgaria

L 12-13½ cm. Breeds, mostly locally and sparingly, in reedbeds, often adjoining small open patches and mixed with bulrush stands. Fond of dense areas of fallen reed, where it often hops along low down. Mainly resident in W, migratory in E (present at Austrian breeding sites mostly Mar-Sep). Does not perform song-flight. Nests low down in reeds.
IDENTIFICATION: Quite similar to Sedge Warbler, yet distinctive when seen well. Is marginally larger and more compact. Often hops on ground or near water, frequently flicks tail and raises it slightly. Differs from Sedge Warbler in: short primary projection (at most a third of tertials, two-thirds on Sedge): whiter supercilium, which is squarer-ended and broader at rear; more uniformly dark crown (can appear unstreaked brownish-black in field) and cheeks, lower edge of cheeks with hint of narrow black moustachial stripe; reddish-brown tone in fresh plumage (spring), especially on rump, nape, neck- and breast-sides; whiter underparts (not buffy yellow-white). – Variation: In E Turkey, Caucasus and Middle East (ssp. Mimicus) more like Sedge Warbler, with greyer-brown, less rusty plumage and paler, more streaked crown.
VOICE: Call a muffled, ‘throaty’ clicking ‘treck’ (thus thicker voice than Sedge Warbler, rather like Stonechat). Variations include shorter ‘trk’, which in excitement turns into fast clicking series, ‘tk-tk-tk-tk-…’; also rolling ‘trrrt’. Song like Reed Warbler’s but more animated, a little faster, softer and more varied, and best recognized by recurring series of Nightingale-like rising whistled notes, ‘vu vu vü vü vi vi …’.