Friday, February 3, 2012

If it walks like a duck or quacks like a duck, don't assume it's a duck! Hybridization of Dabbling Ducks

Mallard drake (Anas platyrhynchos) , Phippsburg Maine
  
Mallard hen, Phippsburg Maine Note her mottled breast feathers and orange and black bill
American Black Ducks (Anas rubripes), hens and drakes, Phippsburg Maine - Totman Cove in front of our house. Note that the males have yellow bills and the females have greenish bills. American Black ducks aren't actually black, but dusky. They were once called "Dusky" ducks.
American Black Duck and Mallard hen, Phippsburg Maine. Note that the Black duck doesn't have  distinctly mottled feathers as the Mallard hen.
Mallard hens and drakes with American Black Duck (in the middle with the yellow bill, slightly larger than Mallards), Smithville New Jersey
Mallard hens and drakes with American Black duck (far right, yellow bill) and Mallard x Black Duck hybrid (foreground, left - green and brown head, no neck ring, slightly mottled neck feathers), Smithville, New Jersey
Mallard hens and drakes with American Black duck and cross of the two species, Mallard x Black Duck
Mallard drakes and hen with single MallardxBlack duck cross - note mottled green and black head on third duck from the left, Bath Maine January 2012
Herring gulls with Mallard x Black duck cross and Mallard drake, Evergreen Cemetery Portland Maine 2011

    
     My father often said "If it walks like a duck and quacks like a duck, it must be a duck." Oh! If only things were that simple.
     When I was a kid, life seemed so mysterious and complex. But, adults seemed to know what was going on and be in command. I believed that when I got older, life would be clearer and I’d have a handle on it too, like my Dad. I always thought I'd get smarter, then armed with more information, I would be a grown up making big decisions. But, not so. It not only hasn’t gotten easier, it hasn’t become more straightforward, either. I've found that as I've become older, I often have too much information to be speedily decisive.
     When I was younger, I’d shoot from the hip quickly. I identified my target, aimed, then fired. Now, I’m bogged down by the layers I see in everything!  I now know there are too many things to consider. Do I call my friend whose husband is in the hospital? She's probably swamped with calls of concern. Maybe I'll leave her alone. When my pal who lost her job calls me, do I give suggestions about what to do, or do I just shut up and listen? Do I take my limping dog to the vet or wait and see if he gets better on his own? The older I get, the more complicated life reveals itself to be. Even birding has failed me there. Oh, if only a duck were a duck were a duck...
     The more I learn about birds and birding, the less I know. Wouldn't you think that a simple duck would be easy enough to identify? No, not so. Of all bird species, waterfowl are the most prone to hybridization, with over 400 hybrids documented! This renders identification of ducks to a huge game of “Who’s Your Daddy.”
     Mallards are one of our most colorful and abundant dabbling ducks. In the winter, I often see them in the company of another common quacker, American Black ducks. This winter, birding has been so mind numbingly dull that even humdrum birds have been a welcome sight. Boredom has prompted me to scan flocks of banausic waterfowl more closely than I might otherwise have bothered to do. And, lo! A star in the east! Nah. Just ducks, but there were ducks that looked funny, not exactly like Mallards, but not like Black ducks, either.
     Mallards were not common in the northeastern United States until after about 1920. In efforts to increase the populations of ducks for hunters, Pennsylvania and Maryland wildlife authorities released more than a half million of them from game farms. Mallards, it turns out, are pretty randy rascals, too. Those from game farms tend to be more aggressive in pairing and mating than wild ones. When their territories began to overlap with other species of ducks, they mixed it up without hesitation.  Mallards tend to hybridize more than any other waterfowl and have crossed with around fifty species other than their own kind (list below)! Some consider Mallards invasive and they are certainly a challenge for waterfowl conservationists.
   The Mallard’s tendency to get it on readily with others stems from numerous factors: there are lots of them, they have many close relatives and in urban areas, there are usually too many dude ducks.
     American Black ducks are genetically quite similar to Mallards. So, hybridization of the two species wasn’t much of a leap. Sadly, the American Black duck population has been on the decline for several decades. Competition for habitat with Mallard bad asses may be one reason.
     In the above photos, the Mallard drakes with the blotchy brown spots on their heads, lack of a neck ring and mottled breasts are actually crosses of Mallards and American Black Ducks. This observation prompted me to scrutinize photographs in my archives of ducks. Lo and behold, there were numerous Mallard x American Black ducks among the throngs from locations across the globe! Well, that’s an exaggeration - just around New England. However, that I have been able to photograph several hybrids without looking for them bodes well for finding crosses of other waterfowl species.
   Nearly twenty percent of the offspring of Mallard hybrids have been found to be fertile and they do back breed. This means that a mixed species duck can mate with another mixed species duck and produce, well…a complex mess for a geneticist. This fallout from duck love adds a maddening, though fascinating, new perspective to bird watching.  Like a three dimensional game of Scrabble, it gets more complicated with every turn if you are lucky enough. 

List of documented hybrids
Northern Pintails (most common cross with Mallards in the Northwestern United States),
Eurasian and American Wigeons,
Cinnamon and Green-winged Teals,
Northern Shoveller,
Gadwalls,
Mandarin and Wood ducks (next to Mallards, Wood ducks cross with the highest number of other species coming in at 26),
Redhead, Ring-necked and Tufted Duck,
Canvasback,
(all of the above have been documented to cross with other species besides Mallards, too! Can you say “paaaaaaaaarty?”)
Eiders,
Hooded Mergansers,
Common Goldeneyes,
Geese
The information  in this essay was obtained from a host of internet sources. Thanks to all who actually did the research for the rest of us.

30 comments:

  1. Or qauck up?

    Nice to see you back. Mallards were fairly uncommon in the Maritimes, too, but their numbers are increasing.

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  2. Michelle and KaHolly, thanks to you both. I'm not sure how to respond to those goof ball puns! Maybe I should just shut up and be thankful that I was missed.

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  3. Sounds like a good title for my post next week only replacing "duck" with "goose" I took several photos of a field of Canada Geese. I was particularly interested in a strange shape on a stump in the middle of the field. I figured I would zoom in once I downloaded the photos. Boy was I surprised when the field was full of decoys and the strange shape was a hunter covered in camo. Just his face was clear. In one of the photos he was even waving at me. I laughed and laughed at myself.
    Your ducks look like someone shook up a bag of ducks and dumped them onto the ground.
    Nellie

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    1. Nellie, thanks for the read and comment. That's pretty funny about the geese and the hunter. It's a wonder you didn't get shot at! I also had a flock of Canadas in here with a Frankengoose with them. It was a mix of Canada and domestic, probably. It really stood out from the crowd. This experience has heightened my desire to look carefully at all the members of any flock from now on.

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  4. Robin, Such a good read. Lovely photos. Happy you are doing this.
    Kris.

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  5. Could that be a human tendency ???
    bmc

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  6. So good to have you back.

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  7. Welcome back to the living!


    And did I understand this article to say Mallards get it on with Eiders? HooWee1 That’s got to be mighty interesting!

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  8. Margaret McPherson (FB)February 4, 2012 at 11:39 AM

    Margaret McPhersun commented on your link.

    Margaret wrote: "Beautiful birds. Never knew that about them. Thanks for the insight, I need to look a little more closely next time I see some!"

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  9. About mallards: When I lived in MD (but I am a true Mainer by birth!!!), I knew many of the wildlife biologists at Patuxent research Center. That's where all the bird-banding data is collected and analyzed. They also do many studies on birds of all types. I remember that these ornithologists call birds that are mallard crosses "idiot mallards", presumably because they don't know who they are supposed to mate with. The strangest that I have seen have been mallard/domestic duck hybrids - sometimes with a bright green head and totally white body, or other wacky combinations of plumage colors. Really funny-looking ducks!

    When I was a ranger/naturalist at the state wildlife sanctuary in MD, we had upwards of 9,000 Canada geese there every winter. It was quite a sight, and it was also a fascinating place to work. Well, here's another story about strange hybrids. There was a domestic goose (greylag) that showed up there and hung out with the Canada geese for years. The maintenance guys named it Diesel because it was as loud as a diesel engine. Well, lo and behold, Diesel mated with a Canada goose and produced an unusual offspring: black head and neck with the white chin strap of a Canada goose, but the gray body was just like a domestic goose with a huge butt. We started calling this one "Son of Diesel". It was so interesting to see such things like this at work!

    Carol Beyna

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  10. Wonderful to see you back Robin, only you could make ducks such an entertaining read! Excellent images, loved the first reflections of the mallard duck and the four trekking across the snow.

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  11. A duck is a duck not madder what it mates with. when it grows up I'm duck hunting it stiil teste good. but yes it would be hard to idenify ok so how many can I have of these..? Would be the question.
    Betty B

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  12. Kathie Brown Nice blog. I did not know that mallards crossbred with so many species!

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  13. Where do I start with all the thank yous? You guys make me feel great! PerthDP, that was THE perfect compliment, "only you could make ducks such an entertaining read!"

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  14. A Simple Shutterbug (OS)February 6, 2012 at 11:44 AM

    Hey! Robin, good to see you here with new photos and a very interesting post. I had no idea this was happening, but it makes me wonder about some of the ducks I've seen in our area.

    A Simple Shutterbug
    February 05, 2012 08:53 AM

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  15. Great post!! Not just restricted to birds, our Ontario coyotes are hybirdized, probably with dog,and wolf. Boom & Gary of the Vermilon River, Canada.

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  16. A wonderful post to read Robin... we as a species have a lot to answer for..
    Lovely images..
    Take care.

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  17. Wonderful post and information. Your ducks images are fantastic.

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  18. Great post and photos. Mallards have bad habits! They hybridize with Australian native species as well!

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  19. Very informative. Love the photos.

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  20. thanks for showing us the hybrids - glad to know not all of the 'mules' are infertile. :)

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  21. Fantastic post Robin! Your writing is wonderfully entertaining and thoughtful. Speaking of hybrids I recently saw a jet black duck with that green luminescence subtly mixed in through out the head and body, all built onto a mallard chassis. I wish I could have gotten a good picture of this guy. It was amazingly beautiful!

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  22. No matter what they are, that's a lot of ducks! Beautiful ducks, at that. We get a lot of mallards, but don't really see black ducks.

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  23. They certainly seem to have a lot of fun ;-)

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  24. Interesting read, great shots.

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