The willow warblers appearance is similar to the chiffchaff: both have olive-colourings. The willow warbler has greenish upperparts, pale yellow underparts, and an off‑white belly which gives it a soft, understated beauty. A pale eyebrow stripe, known as a supercilium, adds to its gentle expression. Its distinct song helps tell them apart though; while the chiffchaff repeats its sharp ‘chiff‑chaff,’ the willow warbler delivers a sweet, descending warble that is often considered one of the loveliest sounds of spring. 

Willow warblers favour young, open woodland and scrubby habitats, especially areas with birch, willow and alder trees. They build dome‑shaped nests close to the ground, often tucked into vegetation. 

Despite weighing just around 10 grams, this tiny bird completes one of the longest migrations of any small bird. This slender, delicate warbler arrives in the UK from April and remains until early autumn, before beginning its remarkable migration to southern Africa. It’s astonishing journey is made even more unusual as it moults all its feathers twice a year - once on its breeding grounds and again after reaching Africa. The reason behind this unusual double moult is still something of a mystery. 

The willow warbler is an active and agile forager. During spring and summer, its diet is almost entirely insectivorous, made up of small insects and spiders which it gleans from leaves and branches with remarkable delicacy. As autumn approaches and insects become scarcer, it switches to softer fruits and berries. This seasonal change in diet helps them build vital fat reserves needed for their long migration to Africa. 

Although still one of the UK’s most common summer visitors, with around 2.4 million breeding pairs, the species is classified as Amber under the Birds of Conservation Concern. Declines may be due to habitat loss and pressures on their African wintering grounds.