Ducks, Geese and Swans (Anatidae)
These birds are well known wherever there is water, whether for their colourful plumage or their often harsh, insistent honking, quacking or whistling calls. Over the years, human have interacted with this bird family perhaps more than any other- for hunting, eating, collecting eggs, stuffing pillows, ornamenting parks, and even serving as guard animals!
Waterfowl are extremely well adapted to life in three media- air, earth, and water. Their narrow, pointed wings allow most species to be good flyers, which is important, as many species are migratory. Waterfowl spend most of their time on the water, using their webbed feet to paddle around on the surface. Some species dive for their food, while others simply dabble on the surface, turning their bodies upside-down to reach underwater plants with their bills. A group of ducks, all upside-down with their tails in the air, makes an amusing sight! The bills of most waterfowl are broad, flat, and rounded at the tip, making them useful for grazing on land or grabbing plants from lake bottoms. Some ducks, however, particularly the divers, eat more fish and invertebrates, and these birds tend to have narrower bills.
There are two subfamilies of waterfowl in the Arctic: the ducks (Anatinae) and the geese and swans (Anserinae). While these birds are similar in many ways, there are some important differences between them.
Unlike ducks, geese and swans moult only once a year, and retain the same colouration year-round. When they moult, they lose all their flight feathers simultaneously and become flightless. Because they are large birds, however, they are generally able to defend themselves against most predators. Geese and swans take 2-3 years to reach maturity, after which they mate for life. Pairs stay together throughout the breeding season, with the female incubating the eggs while the male guards the nest, fiercely chasing off all intruders. Swans nest in solitary pairs, while geese prefer to breed in colonies, although this varies between species. These birds always nest near water, either the ocean or freshwater on the tundra, but the longer legs of geese make them better able to walk on land, where they often search for food in grassy areas.
By contrast, ducks lose their feathers twice a year, but males and females moult at different times. Males experience their main moult shortly after breeding, with some species migrating to special moulting grounds for this purpose; the females are left to incubate and raise the young by themselves. The males replace their flight feathers and grow drab plumage, which they wear for most of the summer in the Arctic. Later in the fall, a second, minor moult- which does not affect the bird's ability to fly- replaces this non-breeding plumage with the male's more brightly coloured breeding plumage. This is important because, unlike geese and swans, male ducks must display to attract a new mate each spring. Unlike most other birds, male ducks are therefore bright-coloured in the winter and spring, and dull for summer and fall. Female ducks, on the other hand, are generally drab coloured year-round, experiencing their major moult in late summer, once the young are independent. Their minor moult occurs in the spring, just before the breeding season. After their ducklings have hatched, female ducks of many species often assemble their broods into large groups called 'creches', with one or two females looking after twenty or more ducklings.