Quails

Question
How do you tell the sex of quails?

Answer
Quails???

I'm an expert on budgies, so I have no idea why you're asking me this, but I happen to know off the top of my head that  the female usually exhibits a shorter plume (the curved structure on the top of the head). This is most easily determined in comparison to a male.

There are differences in the plumage between males and females, but this varies depending on the species.

I hope this helps.  This is at least what my grandfather told me; he hunts them.  He's been hunting quail for twenty years, so I'd take his word.