Mottled Ducks: Anas fulvigula

Appearance:

Mottled ducks are large and brown in color but appear very dark when viewed at a distance. Mottled ducks are darker than female mallards, but slightly lighter in color than black ducks.

The mottled duck belongs to a worldwide group of approximately 20 species of closely related ducks called the mallard complex. All the species in this complex have a similar body shape, but have varying feather characteristics and coloration that enable them to be distinguished from one another.

The Florida mottled duck is easily distinguished from the male mallard in that the male mallard's head has bright green iridescent coloration. Distinguishing a mottled duck from a female mallard can be more difficult, however. The neck and head of a mottled duck is lighter colored than its body feathers, whereas the female mallard does not have this color pattern. Also, the female mallard has a broad, white wing bar above and below the colored portion of her wing (called the speculum). The female mottled duck lacks the upper wing bar but may have a faint lower bar.

Because the plumages of male and female mottled ducks are similar, the easiest way to tell them apart is by bill color. The male mottled duck has an olive green to yellow, solid color bill, while the female has an orange to brown bill with dark blotches or dots. These dots are most prevalent on the underside of the female's bill.

Habitat:

The mottled duck (Anas fulvigula) is a non-migratory, close relative of the mallard (Anas platyrhynchos). The Florida mottled duck (Anas fulvigula fulvigula), often called the Florida duck or Florida mallard, is a unique subspecies found only in peninsular Florida, residing in both brackish and freshwater marshes. The Florida mottled duck spends its entire life within the state and has inhabited Florida for thousands of years. Therefore, the management and protection of this subspecies is primarily the responsibility of the Florida Fish and Wildlife Conservation Commission (FWC). The long-term well-being of Florida mottled ducks is threatened by crossbreeding with feral, domesticated mallards and the FWC is working hard to combat this problem.

The Florida mottled duck is one of a few non-migratory ducks in North America. They occur only in peninsular Florida where they are found both on the coasts and inland. The Florida mottled duck appears to be adaptable with regard to the habitats it uses and has been found using wetlands and related upland habitats associated with ponds, marshes, lakes, rivers, canals, ditches, mosquito impoundments and brackish and salt-water areas on the east and west coasts.

Florida mottled ducks are commonly seen using small prairie wetlands, flood plain marshes of the St. Johns and Kissimmee rivers and coastal impoundments. Rapid changes in the landscape of south Florida, attributed mostly to agricultural and urban development, have raised concerns about the status of these wetland habitats and the wildlife that depend on them.

 

Behavior:

Approximately 40 percent of the mottled duck's diet consists of animal matter such as insects, snails, mollusks, crayfish and small fish. The remainder of its diet is composed of grass seeds, stems, and roots; seeds of other marsh plants; and bayberries.

Florida mottled ducks have an intrinsic, aesthetic value and are highly prized as a game bird. Also they are a defining member of the unique suite of species characteristic of the prairie ecosystem of south Florida.

It will take an effort by not only the FWC, but all Floridians, to ensure the continued existence of the Florida mottled duck.

Florida mottled ducks nest from February through July. The females tend to locate their nests in dense vegetation (tall grasses, rushes or palmetto thickets) on the ground near water. The nest is built of vegetation and is lined with down. Only 1 brood each year is raised and females typically lay 8-10 eggs called a clutch. The eggs are creamy-white to greenish-white and are incubated within 25 to 27 days.

Unlike such birds as the mockingbird or blue jay, which raise their young in the nest for weeks, mottled duck females will move their ducklings to water within 24 to 48 hours of hatching. Young mottled ducks are capable of flight at 60 to 70 days of age.

Florida Fish and Wildlife Conservation Commission (FWC) biologists have conducted an aerial survey of Florida's mottled ducks every March since 1985, to provide an estimate of the density of birds within a central area of their range. The FWC uses this density estimate to monitor the status of the mottled duck population. In 2003, the FWC began to redesign the survey to improve its efficiency and provide a more reliable density estimate, one that is representative of the entire mottled duck population.

 

Hybridatization - The problem

Feral mallards are mating with mottled ducks, producing a hybrid offspring. State biologists are observing more and more mixed flocks and mixed pairs in the wild and these. These hybrid offspring are fertile, which further compounds the problem. Every mallard released in Florida can potentially contribute to the hybridization problem and the result is that fewer and fewer pure-bred Florida mottled ducks are left each year. The complete hybridization could result in the extinction of the Florida mottled duck.

Hybridization - The problem and what you can do to help.

Additional Information:

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Image Credit: Aida Villaronga