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Confusing Summer Eclipse Plumage of Waterfowl

male mallard duck in eclipse plumage
Eclipse plumage of male Mallard. Mihael Grmek, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

Male ducks and other waterfowl have colorful, distinct plumage. For a month or more after breeding, a male duck will molt and sport dull plumage like the female.

These plumage stages are called “basic (bright) plumage” and “alternate (eclipse) plumage” in ducks. It’s called eclipse plumage since it eclipses the vivid basic plumage. Eclipse plumage is temporary. The next molt replaces the eclipse plumage with the colorful (basic) plumage we see during most of the year.

Females Molt First

Females ducks begin partial body and head molt in spring once they arrive on the breeding grounds or before. For one to three months the female ducks are busy being mothers and caring for their young. After the young have fledged, the female duck loses all her flight feathers at once. This happens in the nesting area.

Males stay in their bright, basic plumage later in the spring than females and begin their molt in early summer. Male ducks have already abandoned their mates and some leave the breeding area. Males of many kinds of ducks have specific molting areas they go to as they begin their summer molt. These areas are often a far distance away from the females.

Wood duck male in eclipse plumage
Wood Duck Aix sponsa, male in eclipse plumage (retains red bill. Credit: Judy Gallagher, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0&gt;, via Wikimedia Commons.

Flight Feathers are the First to Go

The reason for the eclipse plumage is that ducks replace all their flight feathers at the same time. During this time they are flightless. In midsummer, it seems all the male ducks disappear, they haven’t. They are hiding in plain sight or flown off to a distant location. They just look like the females.

First the flight feathers shed all at once. Then the colorful head and body feathers molt (shed) to make way for new feathers.  (Once the flight feather regrow and the birds are able to fly, the bright, eye-catching head and body feathers regrow also.

male mallard duck in eclipse plumage
Male Mallard in eclipse plumage. Credit: Materialscientist, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons.

For both male and female ducks the “summer molt” of flight feathers will last from three to five weeks.

So during the fall, winter, and spring the birds wear the familiar plumage colors we know. It’s summer when identifying ducks looks confusing. This eclipse plumage is mostly seen in adult birds, juvenile plumage is whole other kettle of fish.

Order of Plumage of Ducks

Bright breeding plumage (fall-winter-spring) eclipse plumage (summer) Bright breeding plumage (fall-winter-spring)

birds_ducks_black_mallard.
An American Black Duck (Anas rubripes top left) and a male Mallard (Anas platyrhynchos bottom right in eclipse plumage).
Credit: Jean-Philippe Boulet, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0&gt;, via Wikimedia Commons

Ducks with Eclipse Plumage during Summer

  • Mallard
  • Wood Ducks
  • Blue-winged Teal
  • Green-winged Teal
  • Northern Pintails
  • Northern Shovelers

Works Consulted

Kaufman, Kenn, and Kenn Kaufman. Kaufman Field Guide to Advanced Birding: Understanding What You See and Hear. New York: Houghton Mifflin Harcourt, 2011.

Sibley, David, Chris Elphick, and John B. Dunning. The Sibley Guide to Bird Life & Behavior. 1st ed. New York: Alfred A. Knopf, 2001.

Williams, Ernest H. The Nature Handbook: A Guide to Observing the Great Outdoors. Oxford ; New York: Oxford University Press, 2005.

More on Waterfowl

What is the Difference Between Ducks, Swans, and Geese?

Waterfowl Migration in Autumn

2 thoughts on “Confusing Summer Eclipse Plumage of Waterfowl

  1. I’d love an article on how to care for bee hotels!

    1. Hi Gwen – that’s a good idea.

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