Blyth's Reed Warbler

Acrocephalus dumetorum (Blyth, 1849)

2018-06-03 Tyumen region, Isetskiy district	© Nadezhda Bogomyakova

Description

The Blyth's Reed Warbler is a medium-sized warbler (less than Sparrow); without dark mottles and streaks. The upperparts are plain olive-brown, sometimes with buffy or rusty tinge, especially expressed on rump. It is distinguished from the Marsh Warbler by the "colder" grey or olive coloring; light supercilium extends over the eye, is more expressed than light eye ring; light edges of the flight feathers are slightly marked. From the Eurasian Reed Warbler it is distinguished by same features and by absence of buffy tinge on the flanks. From Paddyfield Warbler it is distinguished by the slimmer constitution; by absence of rusty color on rump; by narrower, dimmer and shorter supercilium. The legs may be as dark (grey, brownish) and light (buffy, buffy-brownish). The seasonal differences of plumage are insignificant, after the summer molting birds become "warmer", rustier, especially on the wings and rump. Sexes are similar. Juveniles are not sure distinguished from adults by the more rustier tone, especially on the wings ad rump. The contact characters: 1st primary is not longer or slightly longer (on 1-2 mm) than wing coverts; 2nd primary is shorter than 5th one; on folded wing the primaries projection is less than 15 mm; claw of rear finger is shorter than finger; bill length 88,8-10,0 mm. Weight 9-15 grams, length about 13, wing 5,9-6,7, wingspan 17-19 cm.

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