This is a largish warbler. The adult has an unstreaked grey-brown back, whitish grey underparts, and a darker undertail, which has white feather tips giving a contrasting pattern. The sexes are identical, as with most warblers, but young birds are yellower below. Some birds can show reduced dark markings on the undertail-coverts (caused by more extensive than usual white tips) and thus are closer in appearance to Savi's warbler than typical birds; however they typically still have a streaked breast and more olive colouration on the upperparts. This is a skulky species which is very difficult to see except sometimes when singing. It creeps through grass and low foliage.
Habitat and Distribution
This small passerine bird is a species found in dense deciduous vegetation close to water in bogs or near a river. This species is a rare vagrant to western Europe. In Britain, a small number of males have set up territories in spring, including a bird in Greater Manchester in 1995
Like most warblers, it is insectivorous.
Five to seven eggs are laid in a nest in a tussock or on the ground.
Calls and Songs
The song is a monotonous mechanical insect-like reeling, often given at dusk. It is similar to the song of other species in the group, but has more of a sewing machine quality, and may be produced for long periods.