Willow Warbler look-alikes

Key differences

The Chiffchaff is very similar in appearance but generally has darker legs (dark brown to blackish), a shorter primary projection, and a slightly rounder head shape. The most reliable distinction is by song: the Chiffchaff's song is a repetitive 'chiff-chaff, chiff-chaff', while the Willow Warbler's song is a descending, melancholic cascade. Their calls also differ: Chiffchaff's call is a sharp 'hweet' or 'whit', while Willow Warbler's is a softer, more plaintive 'hoo-eet'.

Key differences

The Wood Warbler is larger and brighter, with a more vibrant yellow throat and breast, pure white belly, and bright green upperparts. It has a very long primary projection and dark legs. Its song is a distinctive shivering trill followed by a series of accelerating 'pip' notes.

Key differences

Bonelli's Warbler (now split into Western and Eastern Bonelli's Warbler) has a plainer, greyer-green upperparts, whiter underparts, and a less prominent supercilium. Its legs are typically pale, but its primary projection is shorter than Willow Warbler. The song is a rapid, monotonous trill.