Phylloscopus trochilus - Willow Warbler
Feather characters. Barbules are rather short (0.60-0.86 mm) and divided into pigmented nodes and unpigmented or partly pigmented (less than 50%) internodes. Dark stippled pigment often found in distal internodes. Bell-shaped nodes are equally distributed along the entire length of barbules (36-44 per mm). They all are about the same size, slightly decreasing towards distal end. Villi are rounded and internodes are straight. Minute prongs are located at distal part of barbules and at both sides of the pennulum. Barbules have this typical structure for Passeriformes; pigmented, bell-shaped nodes combined with rounded villi.
Field characters. Size 11 cm. Weight 8.7 g (6.5-11.8) (Dunning, 1993). Resembles Chiffchaff. Like that species without prominent field marks. Upperparts brown-green or olive, face and breast yellowish, underparts whiter. Supercilium indistinct, yellow, bordered by indistinct dark eye-stripe. Primaries project further beyond tertials than in Chiffchaff, legs are usually paler, supercilium is slightly more prominent, and crown is flatter, all this giving impression of less round, more slender bird. More active than Chiffchaff. Juvenile often separable in field in having more uniform green-and-yellow plumage, especially on underparts, although some adults might look equally yellow.
Voice. Call 'huwiet' more bisyllabic than similar call of Chiffchaff. Song mellow and fluent series of descending notes.
Distribution. Very common summer visitor. Map: see MapIt.
Habitat. Variety of well vegetated areas with deciduous low trees and bushes. Requires plenty of cover, but avoids uniform woodland.
Food. Mainly insects, often caught in short pursuit or in sallies from perch.