It looks like the courting has begun for Harlequin Ducks.
Somewhere I'm remembering that they pair off rather early in the fall and will aggressively defend their ladies from other interested parties.Anyone having more info or corrections to my thinking I'd like to know. I can't seem to find a reference to validate my muddled thoughts.
https://flic.kr/p/MooWXy - Semiahmoo photo of two pairs.

Eric Ellingson