The Savi’s Warbler (Locustella luscinioides) is a species of Old World warbler in the grass warbler genus Locustella. It breeds in southern Europe and temperate western Asia. It is migratory, wintering in northern and sub-Saharan Africa.
This small passerine bird is found in reed beds, usually with some bushes. Three to six eggs are laid in a nest in reeds. The adult has an unstreaked grey-brown back, whitish grey underparts and a lack of throat streaks, which is a distinction from the River Warbler. The sexes are identical, as with most warblers, but young birds are yellower below. Like most warblers, it is insectivorous. This is not a shy species, but can be difficult to see in the reeds except sometimes when singing.
The upper-parts of Savi’s Warbler are a uniform dark reddish-brown, sometimes with a slight greenish tinge. It has indistinct buff eye-stripes, dark lores and pale brown ear-coverts. The brown biak is slender and the irises are also brown. The chin, throat and belly are whitish-buff and the rest of the underparts sandy brown. In the breeding season, both upper-parts and underparts are slightly paler. The legs are brown. The bird is around 14 cm (5.5 in) long.
The song is a trill very similar to that of the Grasshopper Warbler but slightly lower pitched and less prolonged. It is often preceded by a series of low ticks which gradually merge into the trill. The bird sings from high on a reed head with open beak and vibrating throat. Both males and females sing.
Very common in the Danube Delta in spring – summer.