The family of Ducks and Geese occurs in all continents of the world except in Antarctica. The birds grow up to 30 - 180 cm long and live essentially on the water. The front three toes are webbed, the fourth toe is small and shifted upwards. All species swim, some dive well. Most species fly well, only a few are flightless. However, shortly after the breeding season, the birds adopt simple plumage and shed all flight feathers, so that they are unable to fly for some time. The nests are very diverse: there are nests on the ground, in ground caves, in steep walls and in tree hollows. The clutch comprises 4 to 12 eggs, the incubation lasts between 3 and 5 weeks and the young leave the nest soon after hatching.