The Willow Warbler is very similar to a Chiffchaff, but their legs are paler and they tend to have more pale yellow in their plumage, plus a more pronounced supercilium (eye stripe). However, this is not always reliable or clearly visible. They do have a very different song - a sweet lilting, descending whistle, and as this one was singing it was easy to recognise. They are quite elusive birds, hiding in the foliage. They can be found in the Spring through to Autumn, in the trees, especially willow. This one was on the River Walk, not far from the stepping stones.