Willow warbler Phylloscopus trochilus

Willow warblers are slim, delicate birds of woodland, scrub, parks and gardens. They are green above and pale yellow below, with an off-white belly and eyebrow stripe. Willow warblers and chiffchaffs are both very similar, olive-coloured warblers, so are best identified by their song: chiffchaffs sing ‘chiff chaff chiff chaff’. Willow warblers have pale legs, while chiffchaff legs are dark grey.


The willow warbler can be heard singing a melodious, warbling song from amongst tree canopies. Willow warblers are migratory birds, breeding in Europe and migrating to southern Africa for the winter. They are unusual amongst birds in that they moult all their feathers twice a year – once at their breeding grounds and once at their wintering ground. The reason for this is unclear. Like other warblers, they are insectivorous but will eat berries and fruit in autumn.


  • Length: 11-13cm
  • Wingspan: 19cm
  • Weight: 10g
  • Average Lifespan: 2 years


Classified in the UK as an Amber List species under the Birds of Conservation Concern review.


A widespread summer visitor.

When to see

April – September


  • The willow warbler is the most common summer visitor to this country, with more than two million breeding pairs setting up nests for the season.

Common name

Willow warbler

Species name

Phylloscopus trochilus

IUCN Red List status

Least concern

When to see in Scotland

April – September

Where to see in Scotland

Scottish Wildlife Trust reserves such as Garnock Floods or Balgavies Loch.

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