Greater White-fronted Goose, Anser albifrons
Adults, above, and below, flying, with white at the front of the face, and black patches underneath so extensive that they have merged. The amount of black shown by adults varies widely among individuals, as illustrated below.
Adults showing the variation in the amount of black marking on the underparts, from none on the rear two to quite heavy on the front bird.
A juvenile, brown, without the white front, and with a pale orange bill and light-colored irises.
Above, beginning transition to adult plumage in January of the first cycle, with the white front just starting to come in, no black patches yet; as illustrated above, some birds of this species never develop the black patches.
A leucistic Greater White-fronted Goose, landing; the tan color is lighter than any normal bird of this species would show in any plumage, while the white feathers behind the bill mark this as an adult.