Order Anseriformes
This order contains 150 species of living birds, almost all of those species are water fowl (duck, geese and swans) with a few species of screamers. One common characteristic of many of these birds are their seasonal migrations and appearance on nearly all continents.
Physiology and reproduction
Members in this order vary in size from the African Pygmy Goose, 30 cm (1 ft) and 250 grams (.5 lb.) to the trumpeter swan with 1.5 m (5 ft) and 17kg (more than 37 lbs). This order can be found on every major continent and island except Antarctica.These birds are strong swimmers and have a medium bill. The bill varying in morphology among species, coinciding to feeding behavior. These bird have specialized physiological respiratory systems of diving ducks and utilize the nasal glands for salt excretion. Copulation occurs in the water while nests are usually built near the shore while some species nests are built over water or in cracks and crevices. Some birds exhibit incubation (such as the Magpie Goose, pictured above).
Importance
These birds are of interest to many people, such as, researchers who are intrigued about how these birds survive and navigate such intense migrations. These birds also provide great insight in wetland ecology as indicators of the quality of their specific environment.