American Black Duck (Anas rubripes)
Very similar in looks to female mallards, don't you think? But notice his bill is YELLOW not orange like a female Mallard. True they are not really black but actually chocolate brown.
Time for a rest
I'm sorry there were no female black ducks around, or I'd show you the female looks very much like the male, although her bill is is a dull green.
Hanging out with Mallards
They often flock with Mallards (and sometimes breed with them too) so here you can see that the American Black Duck really is darker than a female Mallard.
I am connecting to Stewart M's Wild Bird Wednesday HERE