He's probably worked out that if he wakes up early and wants a cuddle/some company, then making a racket will work! One of our greys is like this. Once he has woken up and is ready for his morning tickles, we are treated to the dawn chorus (to be fair, usually around 8.30 at this time of year). Nothing to do with impending babies. It's his way of telling you he's lonely and wants your company. What's particularly annoying/special about our little performer is that he'll squeak until you come downstairs, settle in for a cuddle, have five minutes then happily return to sleep curled up next to you. By this time annoyed owner is fully awake and can't go back to sleep. Sigh.