The rather long, thick bill is greyish brown with a pale pinkish-brown base on the lower mandible, which is the colour of the feet and legs.

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.

[5][6] Blyth's reed warbler breeds from the Baltic Sea in eastern Europe almost as far as Lake Baikal in Siberia, with a southern isolated population in Central Asia.

[7] This species was a rare vagrant to western Europe, although it has been spreading and increasing in numbers in the region, and was found to have bred in the Netherlands in 2022 and in Scotland in 2024.

[8] In the breeding season, the species prefers the edges of, and clearings within, damp broadleaved woodland, as well as wooded gullies, parks and gardens, scrub and coniferous forest.

The pair builds a nest that is a compact cup made up of plant material and spiders' webs and place it 20 to 60 cm (7.9 to 23.6 in) above the ground.