I was birding in Kenidjack valley, north of St Just, Cornwall, during the morning of 20th September 1990. I had watched the area regularly during the previous seven years. Mentally, I tossed a coin and decided to check the bushes at the bottom of the valley just one more time. This paid off. The valley seemed very quiet, but, at the last bush, around 09.00 GMT, I noticed a movement at the back and focused on the wings of what I thought could be a Pied Flycatcher Ficedula hypoleuca. When it flitted around to the front of the bush, however, it showed a gleaming yellow throat. It proceeded to flycatch in the open. I was so excited and shaking that I had to sit down and study the bird with my telescope. I quickly ruled out the American wood-warblers Dendroica already on the British List, as I was impressed by the remarkable yellow throat and face, unstreaked, bright green upperparts, broad white wing-bars and the heavyish blue-grey bill and legs. After making mental notes I rushed back to the house to consult the National Geographic Society Field Guide to the Birds of North America (1983). To my surprise, none of the wood-warblers seemed to fit. Only two, the Pine Warbler D. pinus and the Cerulean Warbler D. cerulea, seemed even remotely close. I tried unsuccessfully to phone several local people, but eventually succeeded in speaking to Richard Millington and described the bird to him.