A goose is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera Anser and Branta. Some members of the Tadorninae subfamily are commonly called geese, but are not considered "True Geese" taxonomically. More distantly related members of the family Anatidae are swans, most of which are larger than true geese, and ducks, which are smaller.
A greylag goose (Anser anser), with a rail in the background.
Snow geese (Anser caerulescens) in Quebec, Canada
Chinese geese (Anser cygnoides domesticus), the domesticated form of the swan goose (Anser cygnoides)
Barnacle geese (Branta leucopsis) in Naantali, Finland
Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae, Anseranatidae, and Anatidae, the largest family, which includes over 170 species of waterfowl, among them the ducks, geese, and swans. Most modern species in the order are highly adapted for an aquatic existence at the water surface. With the exception of screamers, males have penises, a trait that has been lost in the Neoaves. Due to their aquatic nature, most species are web-footed.
Anseriformes
Anatidae
Magpie goose (Anseranas semipalmata), sole surviving member of a Mesozoic lineage
Cast of Dromornis stirtoni, a mihirung, from Australia.