Just some random things I found interesting.
I just wonder if some of the behavior described is actually courting behavior. A duck raised alone by humans sometimes will try to "court"
It's "flock mates"![]()
I agree with you. I think some of the behaviors are courting, and some are probably warning calls when he is startled.
And here’s a place that sells them. Legally. I don’t know if some type of license is required or what, but I traded some chickens for some wood ducks last year, on a whim. They had leg bands, but unfortunately, they found their way out of my enclosure and escaped before I could learn much about them.

They also have some care info on this site:
https://www.mallardlanefarms-onlinestore.com/woodducks