Mallard

Introduction

The specific name for the Mallard - platyrhynchos - means 'flat billed'. This refers to its classic 'duck' bill, which is adapted for feeding in water, with grooves called lamellae that help to grip vegetation and filter out water.

Identification

The introduced Mallard is a large, dabbling duck with the distinctive males having a glossy green head and neck, a white collar and a chestnut breast. The body is grey-brown and the wings have a blue-violet wing patch within thin white bars. The bill is yellow and the legs and webbed feet are orange. Females are smaller and are mottled and streaked dusky brown. Juveniles are similar to females. Mallards are commonly found in urban areas on ponds and lakes, often with other water birds.

Habitat

The Mallard prefers habitats that have similar seasonal conditions to its original range in the Northern Hemisphere. These habitats include wetlands, grasslands and crops, as well as sheltered estuaries and marine habitats. It prefers still, shallow water with abundant plant life and is most often found on artificial lakes, ponds and wetlands in urban and farm areas, although it may sometimes be found on natural wetlands if they are not far from settlements.

Distribution

The Mallard's natural range is across the Northern Hemisphere from the Holarctic region (North Pole to 30° - 45° latitude) to Hawaii, wintering in southern areas such as the sub-tropics of the Americas and south-east Asia.

The Mallard was introduced to Australia as early as 1862, with a rapid range expansion during the 1950's, and populations in suitable habitat areas are still increasing. In Sydney it was first introduced before 1900 and is now widespread in eastern New South Wales. In Victoria, the first introductions occurred in 1864, then in 1971 to 1972, and it is now widespread in the south. In Queensland, it has been found north to Maryborough, but no breeding has been recorded. In South Australia, it is found in the south-east. In Western Australia, it was introduced before 1912 and is found in and around Perth. It is uncommon but increasing in Tasmania and on King and Flinders Islands. It has also been introduced to New Zealand (from 1867), with several introductions from Britain, Australia and North America, mainly to augment populations for hunting purposes. It is also found on Macquarie Island, Lord Howe Island and Norfolk Island.

Seasonality

In the Northern Hemisphere, the Mallard is strongly migratory, but Australian populations appear to be more sedentary. There are some long distance movements across the ocean, such as from Norfolk Island to New Zealand, but it appears that no birds from the Northern Hemisphere have ever reached Australia or New Zealand except as introductions by humans.

Feeding and diet

The Mallard feeds mainly on aquatic vegetation, but will also eat insects. It feeds by dabbling, up-ending and, sometimes, diving in shallow water and filters wet food through its flat, grooved bill (the grooves are called 'lamellae') or laps up dry food with its tongue and palate.

Communication

Classic duck's 'quack'. Males also have wheezy 'raehb' call.

Breeding behaviours

Mallards pair up only during breeding season, with the male briefly defending a small territory and guarding the female before egg-laying and during the early incubation period. However, after about five days, he abandons the female and the territory, leaving her to complete incubation and to feed and raise the ducklings. The nest is a grass bowl lined with down and well-hidden on the ground or in a hole. The female leads the ducklings to water soon after hatching, and they are able to swim and feed themselves very quickly. The female will often pretend to be injured when threatened, allowing her ducklings to find cover and hide until their mother calls them back. Mallards reach adult plumage at one year and are then ready to mate.

• Breeding Season: July to December
• Clutch size: 12
• Incubation: 28 days
• Time in nest: 60 days

Economic impacts

The Mallard is an adaptable species and is highly tolerant of humans, using artificial water sources and being able to nest in artificial structures such as haystacks and buildings. It has benefited from agricultural developments which provide wetlands, pastures and other suitable habitats.

References

• Marchant, S. and Higgins, P.J. (eds). 1993. Handbook of Australian, New Zealand and Antarctic Birds. Vol 1B (Ratites to Ducks), Oxford University Press, Sydney.
• Morcombe, M. 2000. Field guide to Australian Birds. Steve Parish Publishing.
• Simpson, K and Day, N. 1999. Field guide to the birds of Australia, 6th Edition.Penguin Books, Australia.