Am I missing something? The link didn't have the pic of this duck on it. (???) (Did it?)

The mottled duck and the black duck are pretty hard for me to tell the difference. (In pictures; I've never seen one up close and personal, dag nab it.)

The obvious give-away is the lack of white barring at the speculum that the mallard has. Give us a picture and I'll try to be more help.
Link to PowDuck's Homepage
Romans 8:28