Mexican Duck
Mexican Duck
Anas diazi
At a Glance
This duck of the Southwest and Mexico is a very close relative of the Mallard, and was classified as just a subspecies of that species from 1983 to 2020. New research suggests that it is just as distinct as two other Mallard relatives, the American Black Duck and Mottled Duck, so now the Mexican Duck is classified as a full species again. Its main population is in west-central Mexico, far south of the U.S. border, but it is locally common from central and southeastern Arizona to western and southern Texas.
All bird guide text and rangemaps adapted from by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Duck-like Birds, Surface Feeding Ducks
IUCN Status
Least Concern
Habitat
Fields, Meadows, and Grasslands, Freshwater Wetlands, Lakes, Ponds, and Rivers, Saltwater Wetlands, Urban and Suburban Habitats
Range & Identification
Migration & Range Maps
Not truly migratory, but performs seasonal movements in limited local areas. Flocks gather at permanent lakes and rivers during dry seasons, with the birds then spreading out into other areas during rainy seasons.
Description
Both sexes are similar to female Mallard, with mottled brown body plumage, but somewhat darker overall, especially on the tail and undertail coverts. A patch (speculum) on the trailing edge of the wing, obvious in flight, is blue at the center, with white borders that may be narrower than those of Mallard Male has bright yellow bill; female's is dull olive to orange.
Size
About the size of a Mallard or Herring Gull
Tail Shape
Rounded, Short, Square-tipped
Songs and Calls
Similar to Mallard. Male gives a thin rreeb; female makes loud quacking, like barnyard ducks.
Habitat
Mostly around shallow freshwater marshes of lakes and ponds, also along slow-moving lowland rivers and in irrigated farm land.
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Behavior
Eggs
Usually 5 – 9. Whitish to gray to olive-buff, unmarked. Incubation is by female only, about 28 days. When leaving the nest during incubation, the female will cover the eggs with down.
Young
Leave nest within a day after hatching, are led to water by female. Young are tended by the female but feed themselves. Age at first flight 52-60 days. Probably 1 brood per year, perhaps rarely 2.
Feeding Behavior
Forages in water by dabbling, submerging head and neck, or up-ending, rarely by diving. Forages on land by grazing, plucking seeds, or grubbing for roots.
Diet
Omnivorous. The majority of the diet is plant material, including seeds, stems, and roots of a wide variety of different plants, including sedges, grasses, smartweeds, and many others; also various kinds of waste grain. Also eats insects, crustaceans, mollusks, tadpoles, frogs, earthworms, and sometimes small fish. Young ducklings may eat mostly aquatic insects.
Nesting
Pairs may form many months before nesting activity begins. Timing of nesting season may vary, depending on local rains and water conditions. The male stays with the female at least until incubation of the eggs has begun. Nest: Female seeks and chooses site for nest. Site is often more than 50 yards away from the nearest water, usually on the ground in an open meadow but surrounded by concealing vegetation. Nest is shallow bowl of plant material, lined with down.
Climate Vulnerability
Conservation Status
Fairly widespread in Mexico and locally in the southwestern U.S., but total population is probably under 80,000. A warming and drying climate throughout most of its range is likely to have a severe impact in reducing its available habitat.