The Mallard (Anas platyrhynchos) is a familiar and widespread duck found in nearly all wetland habitats across North America. This adaptable species thrives in diverse environments, from marshes and lakes to urban parks and agricultural fields, making it a common sight for many. Their ability to forage on a variety of food sources, including aquatic vegetation, insects, and even agricultural grains, contributes to their success. This comprehensive guide explores the habitat, diet, nesting habits, behavior, and conservation status of the Mallard, providing insights into the life of this abundant waterfowl.
Habitat
Mallards are incredibly adaptable and can be found in a wide array of wetland environments. Their preferred habitats include permanent wetlands such as marshes, bogs, riverine floodplains, beaver ponds, lakes, reservoirs, and ponds. They are also commonly observed in more managed landscapes like city parks and farms, as well as estuarine areas. In addition to these, they frequent prairie potholes and ephemeral wetlands, and can be seen foraging in roadside ditches, pastures, croplands, and rice fields. This broad habitat tolerance allows them to thrive across vast geographical areas.
Food and Foraging
As generalist foragers, Mallards exhibit a diverse diet that changes depending on the season and availability of resources. They are dabblers, meaning they feed at the water’s surface by tipping forward, not by diving. Their diet consists of seeds and aquatic vegetation, which they gather by dabbling. Mallards also forage on land, roaming shorelines and fields to pick at vegetation and prey. During the breeding season, their diet shifts to primarily animal matter, including aquatic insect larvae, earthworms, snails, and freshwater shrimp. In agricultural areas, particularly during migration, Mallards consume significant amounts of cultivated seeds and grains. In urban settings, they are well-known for readily accepting food handouts from park visitors.
Nesting Habits
Nest Placement
Mallards typically build their nests on the ground in dry, secluded areas close to water. These sites are often concealed by overhanging grass or other vegetation, offering protection from predators. While ground nesting is common, Mallards also adapt to nesting in agricultural fields, particularly in crops like alfalfa, winter wheat, barley, flax, and oats. Both wild and urban populations have been observed readily utilizing artificial nesting structures. Pairs of Mallards search for suitable nest sites together, often during low flights over their habitat in the evening. In some instances, nests may be found on floating vegetation mats or woven into emergent aquatic plants.
Nest Description
The nesting process begins with the female creating a shallow depression or bowl in moist earth. She doesn’t transport nesting materials but rather pulls nearby vegetation towards her while seated. During the egg-laying period, she lines the nest with grasses, leaves, and twigs. She also uses her body to pull taller vegetation over the nest for concealment. Once incubation commences, she plucks down feathers from her breast to further insulate the nest and cover her eggs. A completed Mallard nest typically measures about a foot across, with a central bowl for eggs that is 1 to 6 inches deep and 6 to 9 inches in diameter.
Nesting Facts
- Clutch Size: 1-13 eggs
- Number of Broods: 1-2 broods per year
- Egg Length: 2.1-2.5 inches (5.3-6.4 cm)
- Egg Width: 1.5-1.8 inches (3.9-4.5 cm)
- Incubation Period: 23-30 days
- Egg Description: Unmarked creamy to grayish or greenish buff.
- Condition at Hatching: Hatchlings are covered in down, alert, and capable of leaving the nest within 13-16 hours.
Behavior
Mallards are often observed as abundant ducks in city and suburban parks, where consistent feeding by humans can lead to them becoming quite tame and approachable. However, in more natural settings or areas with significant hunting pressure, they can be very wary of people. Mallards frequently associate with and may hybridize with other species of dabbling ducks. Their behavioral repertoire includes a wide variety of fascinating displays. Males often engage in ritualized behaviors such as head-bobbing, threatening rivals with open bills, or physically pushing against each other. During the breeding season, paired males defend their territories through vigorous aerial chases. Courtship displays by males involve head-shaking, looking over their shoulder, or raising up in the water and flapping their wings. Often, multiple males will gather around a single female to display. A receptive female may encourage a male by nodding her head or paddling with her head held low. Learn more at Birds of the World.
Conservation Status
The Mallard is considered a species of low conservation concern, being the most widespread and abundant duck in North America. Population surveys from 1966 to 2019 indicate stable numbers. Partners in Flight estimates the North American breeding population at approximately 19 million individuals and assigns them a Continental Concern Score of 7 out of 20. Mallard populations tend to increase during wet periods and decrease during droughts in the continental interior, with estimated numbers fluctuating between 5 million and 19 million over the past 50 years.
Despite their abundance, Mallards are also the most heavily hunted waterfowl in North America, accounting for about one-third of all ducks shot annually. State and federal wildlife agencies closely monitor hunting numbers. Like other waterfowl, Mallards are susceptible to lead poisoning from ingesting lead shot while feeding. A mandatory switch to steel shot in the Mississippi Flyway in 1977 significantly reduced lead poisoning incidents. Other threats to Mallards include poor water quality resulting from mercury, pesticide, and selenium pollution, as well as habitat loss due to wetland clearing or drainage and oil spills.
