The booted warbler (Iduna caligata) is an Old World warbler in the tree warbler group. It was formerly considered to be conspecific with Sykes's warbler, but the two are now usually both afforded species status. Booted warbler itself breeds from central Russia to western China, and migrates to winter in the Indian subcontinent as far south as Sri Lanka. It is a small passerine bird, found in open country with bushes and other tall vegetation. 3-4 eggs are laid in a nest in a bush or vegetation. Like most warblers they are insectivorous.