Mottled Duck (Anas fulvigula)

Introduction

The Mottled Duck (Anas fulvigula) is a medium-sized dabbling duck native to the Gulf Coast of the United States and northeastern Mexico, with a separate population in peninsular Florida. It is generally a year-round resident, although local movements may occur when water levels, food supplies or wetland conditions change. Its rich brown, mottled plumage and pale head make it an important species of freshwater marshes, coastal wetlands and wet grasslands.

Physical Description

The Mottled Duck is similar in size to a Mallard. Adults are typically 47–57 centimetres long, with males generally larger and heavier than females. Both sexes have rich brown, buff-edged body feathers, a noticeably paler head and neck, a short tail and a sturdy body.

Sexual dimorphism is limited. Males usually have a yellow to olive-yellow bill, while females generally have an orange-brown bill with dark markings or blotches. Both sexes have a dark spot at the gape, the opening at the base of the bill. The legs and feet are commonly orange or yellow-orange.

The wing speculum is blue-green and is most visible in flight. It usually has a conspicuous white trailing edge, while the broad white wing bars typical of a female Mallard are absent or much less distinct. Juveniles resemble adults but are generally duller and less strongly patterned. Ducklings are dark brown with pale yellowish facial markings and a dark eye-line.

Range and Habitat

Mottled Ducks occur along the Gulf Coast from western Florida through Alabama, Mississippi, Louisiana and Texas to northeastern Mexico. A distinct population occupies peninsular Florida. The Gulf Coast and Florida populations are commonly treated as separate subspecies, although taxonomic treatment of closely related Mallard-complex ducks can vary between authorities.

The species is largely non-migratory. Most individuals remain within or near their breeding range throughout the year, but short-distance movements may occur in response to drought, flooding, changing water levels and food availability.

Preferred habitats include:

Freshwater marshes, ponds, shallow lakes, canals and drainage ditches.
Brackish coastal marshes, wet prairies and coastal grasslands.
Flooded fields, rice-growing areas and managed wetlands.
Dense stands of cordgrass, rushes, sedges and other emergent vegetation used for nesting and cover.

Mottled Ducks generally use lowland habitats and are not associated with high elevations. Suitable nesting cover is usually close to shallow water used for feeding and brood-rearing.

Behaviour and Diet

Mottled Ducks are dabblers. They feed mainly at the water’s surface, by tipping forward to reach submerged vegetation, or by grazing in wet grassland. They rarely dive except when avoiding danger. Their diet includes seeds, stems and roots of aquatic and marsh plants, together with insects, snails, other small invertebrates, crustaceans and occasional small fish.

They are often seen in pairs or small groups rather than in the large flocks formed by many migratory duck species. After breeding, larger groups may form at sites where food is plentiful. Pair bonds can form well before nesting, and males may remain near females during part of the incubation period, although the female is responsible for incubating the eggs.

Breeding may begin in late winter or early spring, with the timing varying geographically and according to wetland conditions. The female builds a bowl-shaped nest on the ground or in low vegetation, often in dense grass, cordgrass, pasture, marsh vegetation or other cover near water. A clutch usually contains 8–12 eggs, which are incubated for approximately 25–26 days. The ducklings are precocial and can leave the nest soon after hatching, following the female to water and feeding themselves.

Identification Tips

Look for a large, sturdy brown duck with a noticeably pale buff head and neck. The following features are useful in the field:

A yellow, olive-yellow or orange-brown bill, depending on sex.
A dark spot at the gape.
Richer and darker body plumage than the head and neck.
A blue-green speculum with a white trailing edge.
A dark tail in apparently pure birds, rather than obvious white tail feathers.
A preference for shallow freshwater marshes and coastal wetlands.

The female Mallard is the most common source of confusion. A female Mallard usually shows a more strongly marked facial pattern, an orange-and-black bill and distinct white borders around the speculum. Mottled Ducks have a paler, less streaked head and neck, a characteristic gape spot and a less clearly defined wing-bar pattern.

American Black Ducks may also resemble Mottled Ducks, but they are generally darker overall and usually lack the Mottled Duck’s strongly contrasting pale head and neck. Identification can be difficult where Mallards occur, because the two species hybridise. Intermediate birds should be identified cautiously, particularly in Florida and other areas with feral or introduced Mallards.

Conservation Status

The Mottled Duck is assessed as Least Concern on the IUCN Red List. This global category does not mean that all populations are secure. Regional declines and local conservation concerns have been reported, particularly where wetlands have been lost or degraded.

The principal threats include drainage and conversion of wetlands, coastal marsh degradation, urban development, drought, saltwater intrusion, erosion and changes in water management. Hybridisation with feral or introduced Mallards is an important genetic concern, especially in Florida, because it can reduce the number of genetically distinct Mottled Ducks.

Important conservation measures include protecting and restoring freshwater marshes, coastal prairie and shallow wetlands; maintaining suitable nesting cover near brood-rearing areas; monitoring population trends; and managing feral Mallards and hybridisation where appropriate. State and federal wildlife agencies also monitor breeding populations, habitat conditions and hunting activity.

Frequently Asked Questions

Where does the Mottled Duck live?

It occurs along the Gulf Coast of the United States and northeastern Mexico, with a separate population in peninsular Florida. It uses freshwater marshes, coastal wetlands, wet prairies, ponds, canals and flooded fields.

Is the Mottled Duck migratory?

It is mainly a year-round resident. Some individuals make local or regional movements when drought, flooding, water levels or food availability alter the suitability of wetlands.

How can a Mottled Duck be distinguished from a female Mallard?

The Mottled Duck usually has a paler head and neck, a dark gape spot, a more uniformly rich brown body and less prominent white wing bars. A female Mallard generally has a more orange-and-black bill and stronger white borders around the speculum.

What does the Mottled Duck eat?

Its diet consists mainly of aquatic and marsh plants, seeds, stems and roots, supplemented by insects, snails, crustaceans and other small invertebrates. Small fish may be taken occasionally.

Where does the Mottled Duck nest?

The female usually nests on the ground in dense grass, cordgrass, rushes or other low vegetation near shallow water. The nest is lined with plant material and down, and the usual clutch contains 8–12 eggs.

Why is hybridisation a concern for this species?

Mottled Ducks can breed with Mallards, including feral or introduced birds. Hybridisation may dilute the genetic distinctiveness of Mottled Duck populations, particularly in Florida and other areas where non-native Mallards are common.

References

Bielefeld, R. R., Brasher, M. G., Moorman, T. E. and Gray, P. N. 2010. “Mottled Duck (Anas fulvigula), version 2.0.” In The Birds of North America, edited by P. G. Rodewald. Cornell Lab of Ornithology, Ithaca, New York. Species account. Accessed 8 September 2026.
Cornell Lab of Ornithology. n.d. “Mottled Duck: Identification.” All About Birds. Identification guide. Accessed 8 September 2026.
Cornell Lab of Ornithology. n.d. “Mottled Duck: Overview.” All About Birds. Species overview. Accessed 8 September 2026.
Florida Fish and Wildlife Conservation Commission. n.d. “Mottled Ducks.” Species profile. Accessed 8 September 2026.
International Union for Conservation of Nature. 2021. “Anas fulvigula.” The IUCN Red List of Threatened Species, taxon ID 22680178. Red List record. Accessed 8 September 2026.
Johnson, W. P., Holbrook, R. S. and Rohwer, F. C. 2002. “Nesting chronology, clutch size and egg size in the Mottled Duck.” Wildfowl 53: 155–166. Article record. Accessed 8 September 2026.
Texas Breeding Bird Atlas. n.d. “Mottled Duck.” Texas A&M University. Species account. Accessed 8 September 2026.
Texas Parks and Wildlife Department. n.d. “Wetland Conservation and Management for the Texas Central Coast: Habitat Management for Mottled Ducks.” Conservation guidance. Accessed 8 September 2026.
Gill, F., Donsker, D. and Rasmussen, P., eds. 2025. IOC World Bird List, version 15.2. Taxonomic checklist. Accessed 8 September 2026.