157643 Mallard - Anas platyrhynchos - male. L 50-65cm. Our most familiar duck. In flight, both sexes show white-bordered blue speculum. Sexes are dissimilar. Adult male has yellow bill and green, shiny head and upper neck, separated from chestnut breast by striking white collar. Underparts are grey-brown except for black stern and white tail. Back is grey-brown grading to reddish brown. Legs and feet are orange. In eclipse, male resembles adult female but note yellow bill and well-defined reddish brown breast. Adult female has orange-brown bill and mottled brown plumage. Legs and feet are dull orange-yellow. Juvenile is similar to adult female. Voice Male utters whistles and nasal calls. Female utters familiar quack. Status Widespread, commonest on lowland lakes, rivers and urban ornamental lakes.