I don't own this duck, but he's one of "Ducky's" older friends hatched in July. He's either the same duck or a sibling of the duckling I use as my icon. All three of these guys are still around, though one is in serious trouble and I don't know if he's going to be OK.
A male mallard has a green head and a curly tail feather.
6wk Drake Rouen/Mallard. If you look close enough you can just see his green coming through on his back and tail feathers in the black/brownish area, as well as the dark area on his head by the eye and top of the head, he is also just starting to get the faintest curl to his tail.
Here is his Momma, she is lighter color from head/tail