Willow Warbler

Phylloscopus trochilus (Linnaeus, 1758)

2018-07-08 Yamal Yamal-Nenets autonomous region	© Alexander Yakovlev

Description

The Willow Warbler is much less than Sparrow. The upperparts are olive-brown greenish tinged; underparts are off-white yellow tinged. It is distinguished from Chiffchaff by the paler legs, by the yellowish tinged upperparts; expressive yellow supercilium. From the Arctic Warbler, Yellow-browed Warbler and Greenish Warbler it is distinguished by the absence of the wing bars. From the Wood Warbler it is distinguished by the not so bright yellow-green color; and the absence of the expressive light edges on the tertials. Juveniles in the first plumage have the clear yellow underparts; more loose plumage. The wing form: 1st primary is longer than coverts on 2-8 mm; 2nd primary is longer than 6th or is equal it or is slightly less it. The outer web of the 6th primary isn't narrowed on tip. Weight 6-11 grams, length 12-15, wing 6,1-7,4, wingspan 18-24 cm.

References