Sunday Duck O’ the Week

It’s time again for John Avise‘s patented Duck O’ the Day, presented every Sunday until we run out of duck species found in North America. (I think we have about two more months.)  Your job is to guess the species. After you try, go below the fold to see the ID, John’s Fun Duck Facts about the species, and a range map.

Here we go.

Hen swimming:

Hen walking:

Hen:

Drake swimming:

Drake standing:

Drake flying:

Pair:

Drake head on:

Click “read more” for the ID, duck facts, and a range map.

Common Goldeneye (Bucephala clangula)

Adults of both sexes do indeed have striking “golden” eyes.  The male also has a round white spot on the face that can be visible even at a distance when it swims or flies (see photo) across a large body of water.  This species of diving duck must hold dual-citizenship in North America because it breeds across most of Canada, winters across most of the United States, and might be found year-round only near the border between these two countries.  Nests are usually in tree cavities in northern boreal forests adjacent to lakes or rivers.  Like many other surface-diving ducks, its diet consists primarily of invertebrate animals including crustaceans, mollusks, and aquatic insects.

A range map from the Cornell bird site:

8 Comments

  1. ThyroidPlanet
    Posted August 30, 2020 at 8:23 am | Permalink

    The “read more” isn’t really showing up in the email version.

    • Posted August 30, 2020 at 10:19 am | Permalink

      From what I know of WordPress’s email system, it automatically sends out the whole post.

      • ThyroidPlanet
        Posted August 30, 2020 at 10:28 am | Permalink

        I don’t know anything about the internals, I’m just pointing this out because it has come across before exactly as the author intended.

  2. Posted August 30, 2020 at 10:06 am | Permalink

    I repeat my speciation question from several weeks ago – where winter/ summer ranges overlap, do ducks still migrate? If so why bother? Do they all migrate a similar distance so northernmost breeders are most northerly in winter? Or are northernmost in summer/winter best adapted to cooler conditions? Equally are southernmost breeders travelling all the way to the southernmost end of range? Speciation opportunities I would hazard!

    • john avise
      Posted August 30, 2020 at 10:52 am | Permalink

      I think the range maps at the Cornell site simply show where the species can be found at each specified time of year. Thus the maps themselves don’t indicate whether, for example, northernmost breeders also are northernmost in the winter. To answer that kind of question would require additional information (e.g. from an accumulation of data from bird-banding returns). In the meantime, your idea could perhaps best be viewed as a potentially testable hypothesis.

  3. rickflick
    Posted August 30, 2020 at 10:10 am | Permalink

    I was a bit confuse by the drakes with rather indistinct white spots. The ones we see are very sharply defined like the “drake flying” above. They are very common in Idaho in winter and often appear with buffleheads.

    • rickflick
      Posted August 30, 2020 at 10:13 am | Permalink

      This is probably the peak of breeding colors:

      • john avise
        Posted August 30, 2020 at 10:58 am | Permalink

        Yes, most of my photographs of drakes (the exception being the photo in distant flight) were of young males not yet in their bright breeding plumage. Thanks rickflick for adding a picture of a drake in full breeding condition.


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