A slender warbler, widespread and common in bushes and open woods; song instantly identifies it in spring; call and leg colour help at other times. Slips easily through foliage with occasional forays after flies; very rarely winters in Europe, unlike Chiffchaff.

Willow Warblers are, on average, a little longer, a little slimmer, a little ‘cleaner-looking’ and fresher than Chiffchaffs, but the differences are subtle at best. Fortunately, their song allows instant identification. Habitat differences, however, are not clear-cut. Willow Warblers are less likely to be seen within tall, mature, broadleaved woods. They like a variety of bushier places: low willows, mixed thickets of hawthorn, elder, young oak, and various other species growing in abandoned railway cuttings, hedgerows with standard trees, forest clearings, and woodland edges; all these are typical sites. Birch trees are especially favoured because they support thriving populations of insects.