Not an easy species to sex, but there are slight differences between the sexes when viewed in good light.

Cocks have a more rusty-coloured crown with a slightly darker bill. Hens have more scalloping to the forhead (hen right)

The hen has a flatter head with the beak more "angled" to the forhead. The cock's head is more rounded with a more gradual curve to the bill (cock left)

Notice the more rusty-colour on the cocks throat and sides of neck (cock left)

Lastly, the hen's back and wings are a lighter shade when compared to the cock (hen right)