On Halloween morning, a flock of about fifteen mallards swam about on Morningside Park’s small pond.
Watching the birds, I realize that I’ve been a little confused about molting and plumage. I understand that differences in plumage may be attributed to the fact that some of our ducks are permanent residents, while others are migrants, just passing through. Still, I could have sworn that last month, the males on the pond were in full eclipse plumage, looking almost like females with most of their head color gone. Yet look at this handsome fellow with his head glowing green and shiny. Is he already growing back his breeding plumage? Or is he heading into eclipse?
To my surprise, this duck and his female companion proceeded to engage in some synchronized head-bobbing. This behavior, which ornithologists call “pumping,” is part of an elaborate duck courtship ritual, sometimes leading to copulation. In fact, on several occasions in spring, I’ve seen mallards copulate right here on the pond, and it’s a somewhat disturbing business. So I watched these two with interest. (Click the arrow to watch my video.)
A visit to Cornell Lab of Ornithology’s The Birds of North America clarifies all things mallard. Apparently, male mallards quickly move out of their drab, late-summer eclipse plumage. So this male is on his way back to his classic breeding appearance. And new pairs start to form as early as September with courtship behavior occurring throughout the winter. Since the ducks are infertile in the fall, they may copulate freely without the risk of eggs being laid in the cold season.
Interesting. Very interesting.