Greylag goose 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
Anser (bird) Maltese swan "Cygnus equitum" was occasionally placed into "Anser", and "Anser condoni" is a synonym of "Cygnus paloregonus". A goose fossil from the Early-Middle Pleistocene of El Salvador is highly similar to "Anser". Given its age it is likely to belong to an extant genus, and biogeography indicates "Branta" as other likely candidate. ?"Anser scaldii" (Late Miocene of Antwerp, Belgium) may be a shelduck. Two species in the genus are of major commercial importance, having been domesticated as poultry: European domesticated geese are derived from the greylag goose, and Chinese and some African domesticated geese are derived from the swan