About Iduna caligata (Lichtenstein, 1823)
The booted warbler, scientifically named Iduna caligata (Lichtenstein, 1823), is a small species of warbler that is similar in size to the common chiffchaff. It has undistinguished plumage: upperparts are plain greyish brown, and underparts are paler. It has a clear pale supercilium and a short bill with a dark tip. Overall, it is a short-winged, rather pot-bellied warbler with a square-tipped tail. This species is challenging to tell apart from Sykes's warbler. The booted warbler breeds from central Russia to western China, and migrates to the Indian subcontinent to winter, reaching as far south as Sri Lanka. It has expanded its breeding range westward in recent decades, and now nests as far west and north as Finland. It is a regular vagrant to Western Europe, with over 180 records in Great Britain up to 2023.
