Well...this thread inspired me to leave the woods and finally hit a marsh. Well, that and woodcock being closed.
Every now and then I would guess they get shot on the Wapsi, I know that refuge By Tripoli has had them in it. Being a birder and into it I can usually pick out a hen black in a flock of mallards, once you can do that you will shot one down there. Might be about 10-15% bigger then a mallard as well.
We don't get a lot of them and they are extremely wary. Shooting one feels like you shot a 10 point buck. Here's one from the 90s with my old faithful lab.
We get a few here. More if the mallards are in. The ones I know of that have been banded came from northern Quebec. When not in mixed groups, they are more wary than a mallard.
Both those spots are too far north for me in a typical year, never been to either. But now that you mention it 5-6 years ago I did hear of one that got shot up that way, friend of mine was in the boat to see it.
We killed one in Saskatchewan 10-12 years ago. I'm sure most guys would have been all jacked up about killing one but to us it was just another black.
First duck I ever shot was a black duck drake out on the salt marshes where I grew up 45-50 yrs. ago. Still my favorite bird to hunt and my favorite decoy to hunt over. Found a LL Bean black duck decoy washed up on shore when I was little and still have it today. It inspired me to get into carving big coastal style decoys out of black cork like to old time carvers of the Eastern Shore. Cigar Daisey always said nothing floats like a duck more than cork.