American Black Duck

I've seen pictures of Black Ducks in field guides and wondered how you could possibly be sure they weren't just female mallards. Well, it turns out that in real life, it isn't as hard as it might seem.
During the field trip I took with the Chicago Ornithological Society in January, we ventured out along a rocky periphery of some property belonging to a power company along Lake Michigan. It reminded me a bit of the jetties at the coast here in Oregon, but these giant boulders were squared up more making the trek less treacherous even though there was an inch or so of snow on them. None-the-less, one from the group slipped into a crack between a couple of the rocks, loosing her boot and hurting her foot enough that see decided to sit this one out. Luckily our leader was able to reach down into the crack and retrieve her boot.

Our destination was a patch of open water, the ice melted by a flow of water from the plant. As we approached, one from the group mentioned to me that we would probably see some Black Ducks, realizing that I had probably not seen any, being from the West. I asked if it would be hard to pick them out from the female mallards. He said, "If you not sure, they aren't Black Ducks". He was right, they are definitely darker than female Mallards and it is easy to pick them out. In the image above, the Black Duck is on the right just above the male Mallard. Here a Black Duck leads a couple of female Mallards. While the body is obviously darker, the color of the feathers are also more uniformly colored. Another obvious difference is the bill. The male Black Duck has a clear, yellow bill with a black tip, just like a male Mallard, not the orange bill with black spotting of a female Mallard. Supposedly a female has a greenish gray bill with spotting, but all that I saw seemed to have yellow bills.

One of things I thought interesting was the fact that the birders in Chicago make it a common practice to throw bread out on the water to bring in the ducks and gulls. I'm not talking a few slices, I'm talking loaves. It seems this would be against birding ethics and I've heard that bread isn't good nutrition for birds, but it seems bird ethics are a bit like pirate laws, they're more like guidelines. :-)

Finally, this last image shows an American Black Duck cross with a Mallard. Notice the green on side of the head of the second bird from the left.