The Kennedy book gives the name of the person who re-translated this song back into Cornish . There is a possibility that he took the word "whek" from another language , but it seems more likely that there had been the word and therefore the bird .
The Nightingale is the bird that supposedly only sings at night and its singing is used as a metaphor for the joys of love , the phenomenom of which was undoubtedly known to the Cornish .There is the possibility that the Cornish wanted to sing about this latter phenomenom in a metaphorical way and that they had heard that a bird existed in other parts of the world that only sang at night viz the nightingale and thought that they would translate the word as "whek". That wouldn't be very logical would it ?