Female almost always have an eye ring of about 1 mm in thickness Feather coloration - Males at least six months old may have a blue gray color of their wing and back feathers. Younger males and females usually have a brownish gray color. Physical Size - If you see male and female birds together, males over six months in age will probably be larger than the female. Males and females of less than six month in age be about the same size. Voice - Males are usually much more vocal then females are.
Females are very quiet and when they do coo have a higher pitched voice.
Bow coos - Males will do bow coos, the mating display where the bird repeatedly touches his beak to the ground, fans his tail, and coos as early six weeks of age. Females will almost never will do a bow-coo unless they have been kept in the company of females without any males for a long period of time. Eggs - Of course only females lay eggs. Females diamonds will lay eggs as early as 12 weeks of age. Is the birds profile smooth and without any unnatural lumps or bumps.