Cetti's warbler are more often heard than seen (so no pic provided!), but the song is unmistakeable. It's a very loud 'QUICK quickety-quick quickety-quick', usually delivered from a reedbed. There are several singing at present along the Twin Banks. If you ever glimpse them they are large chestnut-brown warblers with long rounded tails but they are very hard to spot even when singing very close to you.