Mexican Duck, Hecla Lake, Boulder County, Apr. 24

[Ted Floyd]

Hello, everybody. 

I saw an adult male Mexican duck earlier today, Monday, Apr. 24, at Hecla Lake, eastern Boulder County. Other birds, the past few days, Apr. 22-24, at the Waneka Lake–Greenlee Preserve–Thomas Open Space–Hecla Lake ecological complex have included: wood ducks, hooded merganser, nest-building Swainson's hawks, solitary sandpiper, nesting bushtits, blue-gray gnatcatcher, red-breasted nuthatch, Audubon's and myrtle warblers and hybrids, Gambel's white-crowned sparrows on the move, a meadowlark singing rather like an eastern meadowlark (but I didn't see it), and great-tailed grackle.

Pix of the Mexican duck:

Note the "female Mallard" plumage overall, but with a "male Mallard" bill. The rectrices (flight feathers of the tail) are relatively dark, and there is no evidence of curled tail feathers.

Don't laugh. This is a great angle for ruling out Mallard characters. A male Mallard in this pose would show sharply contrasting black and white on the tail.

Nothing beats seeing the birds together. On the female Mallard (front), note that the white rectrices contrast well with the rest of the body; the effect is more muted on the male Mexican Duck (rear).

The whole gang. Mexican Duck at front right; female Mallard, front left; male Mallards, rear, butts sticking up.

To sum up: "Female Mallard" plumage, but "male Mallard" bill; rectrices (tail feathers) contrasting weakly with rest of body; and no curled tail feathers.

Ted Floyd

Lafayette, Boulder County