Willow Warbler Facts For Kids

A willow warbler is very small — about 11 to 12.5 cm long and weighing around 7 to 15 g, about as light as two or three coins. Its back and wings are greenish-brown, and the belly is pale, from off-white to soft yellow. Young birds are often yellower underneath than adults.

It looks a lot like a chiffchaff, another small warbler, but you can spot the willow warbler by its paler, pinkish-yellow legs and a slightly longer, paler bill. Its song is a clear, falling whistle that repeats, and its short contact call sounds like a two-part "hoo-eet."

Willow Warbler are small songbirds that live across northern and temperate Europe and far into the Palearctic, from Ireland to eastern Siberia. They are easy to hear in spring because males sing from trees and bushes while they look for mates. These birds eat insects, so they are often found where leaves and twigs hide flies, caterpillars, and beetles.

Willow warblers are long-distance travellers. Almost all of them fly to warm places in sub-Saharan Africa for the winter, then return north in spring. Even though they are tiny, some travel thousands of kilometres — one of the longest journeys for any small bird. Would you like to imagine flying that far?

Willow warblers like young, open woodlands and scrubby areas with trees such as birch, alder, and willow. They also use human-made places like coppice and new tree plantations up to 10–20 years old because these areas have lots of low plants and insects. Damp spots with streams, moss, bracken, and low bramble are especially good because they hide nests and bring insect food nearby.

Nests are built low, often close to the ground in thick low vegetation. If animals like deer eat the low plants, there is less cover for nests, so the birds do better where small shrubs and ground plants remain.

Willow warblers are very migratory. In autumn almost all fly from northern breeding areas to winter in sub-Saharan Africa, and some birds from eastern Siberia fly nearly 12,000 km — an enormous trip for such a small creature. They travel in stages, stopping to rest and feed along the way.

Timing follows the seasons: many begin moving south from August to October, spend winter in Africa from about October to March, then head back north from mid-March to mid-May. On the breeding grounds they usually raise one brood between late April and August.

Willow warblers are common in parts of northern Europe. In places like Scandinavia they can be very dense, with some areas holding many pairs per square kilometre, and millions of pairs in Sweden and Finland. But numbers are much lower in other places, and in some regions the birds have declined.

In England the population fell by about 70% over the last 25 years, especially in the southeast, while parts of Scotland show increases. Conservation groups and government schemes give grants and help manage woodlands so young trees and low plants grow back. These actions create safer nesting spots and more insect food. How would you help make a tiny bird’s home safer?

A scientist named Carl Linnaeus first described the willow warbler in 1758 using a name that put it with other small birds. The willow warbler is now placed in the genus Phylloscopus, a group of about 80 similar leaf-searching warblers. The word Phylloscopus comes from Ancient Greek and means "leaf seeker," because these birds look for insects among leaves.

The species name trochilus also comes from Greek and relates to small songbirds. People sometimes called these birds "willow wren" long ago. There are three main subspecies that breed in different parts of the north and spend winters in different parts of Africa.