Sunday Duck o’ the Week

It’s time again for the Duck o’ the Week, designed by biologist John Avise to educate us about the ducks of North America. Today we have a special feature. Guess the duck! The answer and facts about this species are below the fold.

This week really flew by.  All of your readers will have seen this week’s duck, although they may have been unaware of what they were looking at.  I don’t think the Cornell website has a range map for this bird, but it occurs throughout North America and around the world.


Click “read more” to see the ID and Fun Duck Facts:

Domestic Mallard (Anas platyrhynchos), or “Pekin Duck”

Mallards are one of two duck species that have been successfully domesticated by humans (see next week’s Duck O’ the Week post for the other domesticated species).  Domestic Mallards were originally bred mostly for food, so they tend to be larger (up to 2X) than wild Mallards.

They have also been bred for appearance and behavior, resulting in many strains or breeds.  For example, one domestic breed of Mallard known as the “Indian runner duck” stands erect like a penguin and runs rather than waddles.  Many domestic Mallards are entirely white, but these birds frequently interbreed with other Mallards (including wild birds) to produce ducks with a great diversity of plumages.  Domesticated Mallards can be seen worldwide, especially in urban parks and farm barnyards, where they are often the most common and noticeable of ducks.  Indeed, almost any tame or “weird-looking” duck that you can’t otherwise identify probably has at least some Mallard ancestry.

JAC: Runner ducks, which can’t fly very well but can run fast, are often use to control pests in fields and vineyards. (The fifth photo above the fold is a runner.)

Here’s a video of a bunch of runners doing their job in a South African vineyard:

The bird above with the pom-pom on its head is a Crested Duck, another breed of mallard.


  1. Randall Schenck
    Posted September 27, 2020 at 7:57 am | Permalink

    We have several of these ducks here in the urban waters of Wichita. They sometimes make a lot of noise.

  2. ThyroidPlanet
    Posted September 27, 2020 at 8:29 am | Permalink


    Anas platyrhynchos, but domesticated!

    … I’ll be puzzled by that for a bit…

  3. Ken Kukec
    Posted September 27, 2020 at 8:53 am | Permalink

    Guess the duck!

    Will the secret woid come down and we win a hundred dollars?

    • Jenny Haniver
      Posted September 27, 2020 at 7:43 pm | Permalink

      Close but no cigar.

    Posted September 27, 2020 at 9:07 am | Permalink

    Whenever I see all-white ducks like that, I inevitably think of factory-farming, and despair (again) of the world.

  5. C.
    Posted September 27, 2020 at 10:40 am | Permalink

    Oh, is this an example of that new genetic plasticity that the New Scientist recently revealed?

    • John avise
      Posted September 27, 2020 at 11:44 am | Permalink

      No, not exactly. It is however, an example of what must be the tremendous wealth of genetic variation that is available for artificial selection under human auspices. Two other familiar examples of the power of artificial selection (the human-mediated analog of natural selection) are as follows: the great variety of dog breeds that have emerged under artificial selection ultimately from wolf ancestors; and the great diversity of chicken breeds that have been artificially selected ultimately from Red Junglefowl. Of course, hybridization among domesticated Mallard breeds (and likewise those of dogs and chickens) further heightens genetic variety and the efficacy of artificial selection in generating even more morphotypes or breeds.

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