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
Branta thessaliensis range disjunction is less pronounced in the Canada and cackling geese of North America, where unlike in there was no W-E barrier (the Alpide belt) barring range shifts in response to the advancing ice. Branta thessaliensis Branta thessaliensis is a prehistoric species of black goose known from fossils found in Greece. It is among the earliest known members of its genus. Described in 2006, it was of similar size to the Canada goose. It is known from a humerus bone, which differs form the living species by a wider distal end of the diaphysis, a dorsal condyle that is more