Every where I seem to go at the moment I here the song of the Willow Warbler. It's habitat is woods, forests, coppice's, and scrub. Anywhere with a few trees. Today I have seen and heard this lovely warbler in hedge rows with a few trees and on the edge of a forest.
It eats insects, mostly flies but also bees, beetles and aphids. Like a Chiffchaff it constantly looks on leaves and twigs looking for tiny insects.
This one seems to be gathering nest material, they nest on the ground in well hidden thick herbage, perhaps the nest was going to be nearby.
Once you get used to their song identification is easy.
ISO 200 f 6.3, 1/320 sec 500mm focal length