An even more difficult species to sex visually. Cocks (left) tend to have a slightly wider crown and upper mandible when viewed from the top.

 
In side profile the cock (left) has a shorter, stubbier bill while the hen has got a slightly more pointed bill.


Not much difference when viewed in this position, again, notice the cocks stubbier bill (left)
 

When comparing the glossy-green scapulars on the wings, the cock (right) has noticably more green than the hen. In the northern races the cocks have a more purple-ish sheen to the head, not that evident in the southern sub-species that we keep.

 
Lastly, cocks also tend to show more prominent barring on the rump than hens (cock at the bottom)