Ruddy Duck Video
This shows the most frequent display by male ruddies to impress females. It is called “bubbling” and ends with a little sort of burp vocalization.
That sound is hard to hear because of the Canada Goose and Yellow-headed Blackbird background noise.
Ruddies are one of 6 worldwide stifftails (a tribe of related ducks) appropriately named for those stiff tail feathers used for displays.
-Frank