Watching Coot-Looting Wigeons at Buttertubs Marsh

I sometimes wonder why I don’t get bored going to the same birding locations month after month, year after year.  A big part of it is that, on any given day, there is a chance that they will see something different or rare or perhaps even totally new.

This past Sunday, while on an organized outing with a bunch of local birders to Buttertubs Marsh Bird Sanctuary in Nanaimo, I got my “something-new” fix.  In this case is wasn’t a new species of bird — instead it was an inter-species interaction that I had never noticed before – that of an American Wigeon stealing food from an American Coot.

Scene 1: Following the Coot

Coot (Fulica americana) & American Wigeon (Anas americana)

The first of the two species, the American Wigeon (Anas americana), is a duck that is part of the genus Anas sometimes referred to as dabbling ducks.  These duck may feed on land or on the water where they can tip themselves upside down and gather underwater plants up to several inches below the surface.

The second of the two species, the American Coot (Fulica americana), is in the family Rallidae of rails and looks a little like a small black chicken.  These birds may feed on land, by dabbling in shallow water or by diving for plants.

I captured a short video of the food stealing behaviour (kleptoparasitism) with my Panasonic DMC FZ-200 camera.  I may have had too much fun and gotten a little carried away with the presentation.  You be the judge:

At one point there were at least 3 or 4 Wigeon-Coot pairs doing similar food-stealing dances.

On another occasion I watched as a Wigeon tried to manage two Coots at the same time and seemed to spend a lot of time in the middle trying to decide which way to go.  Not a good strategy for a low-intelligence bird it would seem.

Some further comments and other notes resulting from forays into online ‘research’:

  • A 1979 article suggested that the Wigeon is the only duck known to be a regular kleptoparasite (ref [3]).
  • A 1984 article documents Gadwalls stealing food from American Coots (ref [4]).
  • Other ‘dabbling ducks’ in the genus Anas include the Mallard, Wigeons, Teals, Shovelers, Pintails, the Black Duck, the Gadwall and a few others.
  • Wigeons apparently will try to steal food from other diving water birds, not just from coots.
  • Coots, in turn, have been known to steal food from other water birds.
  • Coots will also dive to escape predators (the Coot is one of the easiest birds for the Bald Eagle to catch).

References

A good source of information that I like to use is the Birds of North America online service from the Cornell Lab of Ornithology.  The service is not free but for anyone curious about bird behaviour it’s worth the price in my opinion.  They have a one month subscription that costs $5 if you want to give it a try.

[1] BNA online article on the American Wigeon.

[2] BNA online article on the American Coot.

[3] H. Jane Brockmann & C. J. Barnard,  Kleptoparasitism in birds, Animal Behaviour Research Group, Department of Zoology, University of Oxford, UK
Animal Behaviour (Impact Factor: 3.14). 05/1979; 27:487-514. DOI: 10.1016/0003-3472(79)90185-4

[4] Juan A. Amat & Ramón C. Soriguer, Kleptoparasitism of Coots by Gadwalls, Ornis Scandinavica 15: 188-194.  Copenhagen 1984.

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