It was formerly considered to be conspecific with Sykes's warbler, but the two are now usually both afforded species status.

[1] Booted warbler itself breeds from central Russia to western China, and migrates to winter in the Indian subcontinent as far south as Sri Lanka.

Booted warbler has expanded its breeding range westward in recent decades and nests now as far west and north as Finland.

It is a small passerine bird, found in open country with bushes and other tall vegetation.

Keyserling and Blasius gave no explanation of the genus name Iduna, though in Norse mythology Iðunn, or Iduna, is the goddess of spring and fertility who was changed into a sparrow (or a nut) to enable her rescue by Loki.