The garden warbler is not the easiest of birds to see. They are very drab, in fact they are noted for having no distinguishing features at all. They tend to skulk in foliage for long periods singing, then quickly moving to another perch where they vanish and start singing again. The best way to identify them is their song - a long rambling, flowing, bubbling warble. This one was actually singing out in the open, but some distance away.