Abstract
The growth rates and plumage development of many Anseriformes have not previously been documented, yet this period is an important part of the life cycle. In this study, I calculated the growth rates and documented the physical development of juvenile Mallard (Anas platyrhynchos), Australian Wood Duck (Chenonetta jubata), Ringed Teal (Callonetta leucophrys), Brazilian Teal (Amazonetta brasiliensis), Marbled Teal (Marmaronetta angustirostris), Red-crested Pochard (Netta rufina), Hooded Merganser (Lophodytes cucullatus), Smew (Mergellus albellus), and Coscoroba Swan (Coscoroba coscoroba) at the Livingston Ripley Waterfowl Conservancy. Growth rates and physical development varied among tribes in relation to species specific brood rearing habitats and the differences in predation, diet, and foraging styles within habitats. In addition, fledglings of Anatinae species (except the Mallard) were color marked to study feather replacement postfledge. Juvenile plumage was replaced in all six genera of Anatinae by a formative plumage that included replacement of head, neck, flank and belly feathers.