Blyth's Reed Warbler
Acrocephalus dumetorum
Blyth's reed warbler is between 12 and 14 cm (4.7 and 5.5 in) in length and weighs between 8 and 16 g (0.28 and 0.56 oz). It is a slim warbler with relatively short wings and a long bill. The plumage is rather plain with few distinguishing features and has been described as lacking in "warmer" tones observed in related species. The upperparts are plain olive brown, with less olive on the short, rounded wings. There is a short whitish supercilium running between the base of the bill and the eye, with a dusky stripe through the eye. The underparts are plain and off-white in colour. Voice: Blyth's reed warbler has a variable song in which harsh sounds like ticks, chaks and churrs are mixed in with melodious whistles and mimicry.
ID text from Wikipedia, CC BY-SA 4.0
Great Reed Warbler
Acrocephalus arundinaceus
The thrush-sized warbler is one of the largest species in both its current the family Acrocephalidae, and its former family, the "Sylviidae". It measures 16–21 cm (6.3–8.3 in) in length, 25 to 30 cm (9.8 to 11.8 in) in wingspan and weighs 22 to 38 g (0.78 to 1.34 oz). The adult has unstreaked brown upperparts and dull buffish-white chin and underparts. The forehead is flattened, and the bill is strong and pointed. It looks very much like a giant common reed warbler (Acrocephalus scirpaceus), but with a stronger supercilium.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
And 10 more countries.
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: Blyth's Reed Warbler and Great Reed Warbler.