Hello,
do you have more pictures?
Assuming, it was was taken some weeks ago ( many Chiffchaffs look more mature/adult like at least in Germany by now), your bird gives me mixed feelings:
Coloration seems better for a Chiffchaff:
- untidy and patchy coloration with a grayish back
- Head pattern with subdued supercilium and uniform ear-coverts
- But will this bird get a broad and dark eye stripe when fully grown? Yes, this came into my mind, slightly favoring Willow Warbler.
- Smallish dainty bill with only a small yellowish, not orange bill base. Yes, thanks Lou again!
I am not so sure about legs: can I detect bright orangey yellow colours among the neeedles???
But your bird seems to have a long pp, and a quite short p2 in relation to the wing tip. But before I say that this makes it a Willow Warbler and comment about still growing primaries in such a young bird (can you give date and location please?), I better wait for experienced ringers and BF members you know. Thanks!