Sunday, February 19, 2012

American Black Duck

The male American Black Duck, Anas rubripes, has a dark body and light head, orange-red legs, unblemished yellowish bill, and a black-bordered bluish purple speculum (the brightly colored patch of feathers on the wing). 
I was walking in Brooklyn Bridge park yesterday when I heard splashing and thrashing in the pond. I got there just in time to see a male mallard duck fly away and a pair of ducks in the pond swimming excitedly and shaking their feathers. I may have just missed a duck fight! The male mallard circled overhead and splash-landed in the pond. He was chased away immediately as the duck pictured above rushed at him threateningly. This time the mallard flew away and did not return. The victorious duck bathed with exaggerated wing thrashing and water splashing.

A duck celebrates victory after chasing another duck away. 

The pair of ducks that remained soon settled down in the shallows to preen their feathers. They were a male American black duck and a female mallard. Despite being different species they behaved like a couple. She followed him around the pond, and, as explained, he was chasing male ducks away.

The Mallard duck female, Anas platyrhynchos, at lower right has a blue speculum bordered with white. Her beak is orange with black splotches.  

Male mallards occasionally breed with female black ducks and produce hybrid offspring. The mating displays of the two species are identical. But most of the mixed couples are a mallard male and a black duck female. I haven't seen reports of male black ducks with mallard females, but I haven't searched extensively. If any of my readers can speak about this, please post a comment. Meanwhile, I will consult with ornithologists I know and report back. I hope the ducks continue to visit the pond so I can keep an eye on them and let you know what I see.

The black duck stretches his wing, showing off his speculum and bright foot. The color of the speculum seems to change with the light. This is the same bird as above. Click to enlarge. 

2 comments:

  1. This post is very interesting and educational. Thank you! I may have taken a picture of the very same ducks back on March 16, 2010. I will send you the picture. Someone else may have also blogged about them and actually saw their chicks, here is a link:

    http://birdsandwords-larryz.blogspot.com/2011/06/pier-one-62-ducklings.html

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  2. That's pretty cool. Eric. They could be indeed be the same couple. Thanks!

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