Anser anser, the greylag goose, is a member of the waterfowl family Anatidae. It was first described by the Swedish naturalist Carl Linnaeus in 1758 as Anas anser, but was transferred two years later to the new genus Anser, erected by the French zoologist Mathurin Jacques Brisson, where it is the type species. Two subspecies are recognised; A. a. anser, the western greylag goose, breeds in Iceland and north and central Europe; A. a. rubrirostris, the eastern greylag goose, breeds in Romania, Turkey and Russia eastwards to northeastern China. The two subspecies intergrade where their ranges meet. The greylag goose sometimes hybridises with other species of goose including the barnacle goose (Branta leucopsis) and the Canada goose (Branta canadensis), and occasionally with the mute swan (Cygnus olor). The greylag goose was one of the first animals to be domesticated; this happened at least 3000 years ago in Ancient Egypt, the domestic breed being known as A. a. domesticus. As the domestic goose is a subspecies of the greylag goose they are able to interbreed, with the offspring sharing characteristics of both the wild and tame birds.