The Lesser Whitethroat, Sylvia curruca, is a common and widespread Old World warbler which breeds in temperate Europe, except the southwest, and in western and central Asia.
This small passerine bird is strongly migratory, wintering in Africa just south of the Sahara, Arabia and India.
This is a bird of fairly open country and cultivation, with large bushes for nesting and some trees. The nest is built in low shrub or brambles, and 3-7 eggs are laid.
As with most warblers, the sexes are almost identical. This is a small warbler with a grey back, whitish underparts, a grey head with a darker "bandit mask" through the eyes and a white throat. Like most warblers, it is insectivorous, but will also take berries and other soft fruit.
It is slightly smaller than the closely related Whitethroat, and lacks the chestnut wings of that species. It is likely that the two species separated in the last ice age, with their ancestor being forced into two enclaves, one in the south east, which became the Lesser Whitethroat, and one in the south west which became the Whitethroat. When the ice sheets retreated, the two forms no longer recognised each other as the same species.
Because warblers depend on song for breeding recognition, the change in this important signal would be enough in itself to ensure genetic isolation. The Lesser Whitethroat's song is fast and rattling, and quite different from its relative's scolding song.
A similar situation occurs with the Chiffchaff and the Willow Warbler, where two very similar leaf warbler species are separated by their very different songs.
The Lesser Whitethroat has nine subspecies, of which some has been suggested as species in their own right. Perhaps the best candidate is the small central Asian Sylvia curruca minula, Desert Lesser Whitethroat, with a more sand-coloured back.