I think my budgie has a word for 'sudden darkness', as he sometimes gives the same call when I turn out the light at night - it even seems to have the same pitch as a question in its tone.
Can't remember if I said it here already, but that 'Bok bok bok' sound we associate as the noise chickens make isn't the noise chickens make, really. It's actually their word for 'ground based preditor approaching'. It's not their normal call - we just think it is because it's the noise we always hear when were near them (and we forget to treat ourselves as a factor in the situation)