First the plural of "Goose" is "Geese". Geese "migrate", that is they fly North into the Arctic regions in Spring and South to temperate regions in Autumn.
… They do this because during the Arctic Summer, the Arctic wetlands are warmed by 24 hours of sunlight, the plants grow and the wetlands team with life that is food for the geese (also there are few predators). They therefore bread in the Arctic and raise their young over these summer months. Come Autumn/Winter the ground freezes over and snow covers the vegetation and food ceases to be available for the Geese. They therefore fly South for the Winter to more temperate climate regions where food is available. (MORE) 
