The original Old English word "ċēo" (pronounced with initial "ch") gave modern English "chough"; Chaucer sometimes used this word to refer to the western jackdaw, as did Shakespeare in "Hamlet" although there has been debate about which species he was referring to. This onomatopoeic name, based on the western jackdaw's call, now refers to corvids of the genus "Pyrrhocorax"; the red-billed chough ("Pyrrhocorax pyrrhocorax"), formerly particularly common in Cornwall, became known initially as the "Cornish chough" and then just the "chough", the name transferring from one species to the other.