Booted Warbler

The booted warbler is a reed and tree warbler of the family Acrocephalidae. The plumage is undistinguished, plain greyish-brown on the upperparts and paler below, with a clear pale eyebrow and a short bill with a dark tip. It looks like a short-winged, rather pot-bellied warbler with a square-tipped tail (Wikipedia, general species account).

It is a regular vagrant to western Europe and has expanded its breeding range westward in recent decades, nesting now as far west and north as Finland. The nest is on or close to the ground, or at a maximum of about 1 m, hidden among dense undergrowth (Wikipedia, general species account).