Sykes's Warbler was formerly considered a subspecies of the booted warbler, but is now considered a full species. Its breeding range is from northeast Arabia to Afghanistan. Like the booted warbler, many populations of the species migrate in winter to the Indian subcontinent as far south as Sri Lanka.
It is a small passerine 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.
It is a small warbler, especially compared to others in their genus. They are pale brown (weak tea colour) above and whitish below with buff flanks. The outer tail feathers have pale edges. They have a short pale supercilium, and the bill is strong and pointed. Sykes's is larger and greyer than booted.