Snow geese are known for their white plumage, but many of them are actually darker, gray-brown birds known as blue geese. These birds were once though to be two separate species, but they have recently been found to be merely two different color morphs of the same bird. A single gene controls the color difference.
Snow geese are harbingers of the changing seasons. They fly south for the winter in huge, honking flocks that may appear as a "V" formation or simply as a large "snowstorm" of white birds. They spend the colder seasons in southern coastal marshes, bays, wet grasslands, and fields. Their diet is entirely vegetarian, consisting of grasses and grains, grazed from damp soils or even shallow water.