The mallard is undoubtably the most recognized waterfowl in the world. The familiar duck morphology is complemented with a iridesent blue speculum on the wings in both sexes. On the male, the notable characteristics are the green iridesent plumage on the head and neck, and curled black feathers on the tail. The female's plumage is drab brown.
Mallards consume a wide variety of foods, including vegetation, insects, worms, gastropods and arthropods, although they are not restricted to these. They also take advantage of human food sources, such as gleaning grain from crops.
Most mallard hens breed as yearlings, but they may not have much success; studies show that older hens have much lower duckling mortality than yearlings. Pair bonding starts as early as October and continues through March. Mallard males leave the hen soon after mating occurs. The hen usually lays 9 -13 eggs in a nest on the ground near a body of water. When the ducklings hatch after 26-28 days, the hen leads them to water and does not return to the nest.
After the breeding season, mallards form flocks and migrate from northern lattitudes to warmer southern areas. There they wait and feed until the breeding season starts again. Some mallards, however, may choose to stay through the winter in areas where food and shelter are abundant; these mallards make up a resident populations.
The familiar "quack" of ducks is from the female mallard--it is named the "decrescendo call", and can be heard for miles. A female will give the call when she wants to bring other ducks to her, such as her ducklings, and as a result it is also known as the "hail call".
Most often, they prefer wetlands, where highly productive waters produce large amounts of floating, emergent and submerged vegetation Wetlands also produce a great deal of aquatic invertebrates on which mallards feed.