A group of mallards crosses an icy pond in winter. Courtesy: E. Marks, Audubon Society of Rhode Island

Mallard (Anas platyrhynchos)

Field markings: 23 inches long; males have brightly colored plumage; females are mostly brown.
Habitat: Marshes, wooded swamps, grain fields, ponds, rivers, lakes, and bays.
Seasonal appearance: All year, plus additional overwintering population.

Description

Male mallards have a metallic green head with white collar, rusty breast, green underside, black and white tail, yellow bill, and orange feet. Females are a mottled, tawny brown with a whitish tail and a black and orange bill. Both sexes have a violet blue bar bordered with white lines on the wings.

Life History and Behavior

Mallards pair up for the breeding season but choose a new mate each year. The male sets up a territory around the breeding female to guard her until a week into incubation. The female builds a nest on the ground, usually in well-concealed vegetation or sometimes in hollow logs, near the edge of a pond, marsh, or water body. Nests are constructed of dry grass, reeds, and cattails. At the end of the breeding season before migration, mallards molt and lose their flight feathers. For approximately one month, the birds are flightless. During this vulnerable period, they seek out safe or secluded bodies of water for shelter as they build up a layer of fat for migration.

Mallards are the most common ducks in Rhode Island. They are dabbling ducks, using their broad bills in combination with their large tongues to sieve through the water and mud to consume aquatic vegetation, insects, and aquatic invertebrates. On land, they feed on seeds, shoots, grass, acorns, and grain. Like many other dabbling ducks, mallards are able to spring directly into flight without having to run to take off. This is due to having large wings relative to their body weight.

Mallards are dabbling ducks, often seen splashing about while reaching under the surface of the water for food with their tail ends tipped up above the surface.

Female mallards foraging on riverbank. Courtesty: U.S. Army Corps of Engineers

Special Notes

• Mallards were uncommon summer residents in Rhode Island in the early 1900s, but they are now one of the most common nesting waterfowl in the state.
• The local breeding stock originates from releases and escapees from captive flocks in the early to mid-1900s. Their population continues to expand, benefited by adapting to human influence.
• By filter feeding in the water, mallards consume pollutants along with their intended foods. Trace metals and other pollutants are retained in their feathers and body tissues.
• A major threat to dabbling ducks is the use of lead shot, which was banned in 1991. Feeding ducks consume the small pellets that resemble grain. The lead from the gunshot enters the blood stream after digestion, and often results in death.

Adapted from The Uncommon Guide to Common Life on Narragansett Bay. Save The Bay, 1998.