Within Mallard Ducks (Anas platyrhynchos), females give out the well-known “quack” sound or “decrescendo call”, which can be heard for miles. They use it to beckon other ducks, including their ducklings.

Males, on the other hand, don’t quack; instead they make a quieter, rasping sound.

In the UK, mallards may be resident breeders, or migrants, as many of the birds that breed in Iceland and areas of northern Europe spend the winter here.

Mallards are large and heavy-looking, with a long body, and a broad, long bill. The males and females differ in appearance; the males (drakes) have a dark green head, a yellow bill, and is mainly purple-brown and the breast, and grey on the body. Females (ducks), on the other hand, are mainly brown with an orange bill.

These birds are the most common and widespread duck, and they can be found almost anywhere, including urban areas, as long as there is a suitable wetland habitat, like a pond or lake (full distribution map below).

Source: RSPB (Mallard Duck page)

A. platyrhynchos are fairly large ducks, with an average wingspan between 81-98 cm, and a weight of 750-1500 g.

Mallards are omnivorous, meaning they consume both plant and animal matter. Here, they eat worms, arthropods (insects), gastropods (molluscs), aquatic plants, and occasionally human food sources, including grains from crops. These ducks can be described as “dabbling ducks”, as they feed in the water by tipping forward and grazing on aquatic foods. It is also stated that they rarely dive for food.

The nesting period for A. platyrhynchos starts in April, and peaks in May. During this time, mated pairs search for a suitable nesting site, which can be seen circling in the evenings, low over the habitat. The female constructs the nest once the site is chosen, which would be on the ground, near a body of water. The female then lays 9-13 eggs, which are incubated for 26-28 days. In this species, the chicks are precocial, meaning they are able to be introduced to water and swim within 12 hours after hatching. After mating, the male usually leaves to gather into a male flock for moulting in early June. The females stay and care for the offspring for 42-60 days.

Mallards are strong fliers; migrating flocks have been estimated to travel at 55 mph

Mallards are the main ancestor to most breeds of domestic duck (everything except the Muscovy Duck, Cairina moschata). Also due to the widespread numbers of mallards, some populations have changed enough to be considered separate species. Examples include the Mexican Duck of Central Mexico (Anas diazi), and the Hawaiian Duck (Anas wyvilliana), and in both forms, the male is a dull brown like the female.

A. platyrhynchos are particularly known to form hybrids amongst other waterfowl. Here, they can hybridise with the American Black Duck, Mottled Duck, Gadwall, Northern Pintail, Cinnamon Teal, Green-winged Teal, and Canvasback, as well as Hawaiian Ducks, Mexican Duck, the Grey Duck of New Zealand, and the Pacific Black Duck of Australia (for example).