There are numerous species of Goose, spread across three Genera, but the domestic goose is descended from this species, the Greylag. She is spread throughout the Northern Hemisphere, natively occuring across Eurasia with feral (and vagrant) populations in North America. She has been domesticated for 1,000 years. Her main diet is grass, grain and leafy vegetation. Due to the low energy component, she must graze almost constantly. Geese have a more cohesive family unit than ducks, with both parents
guarding the chicks from predation. The family remains together
throughout the year, joining with a larger flock to make the migration
south or east for winter. They are one of the last migrants to depart, hence the inclusion of "lag" in their name.