The bill is a dull pink with dull brown in the middle and yellow on the tip. The legs and feet are black. A. Juveniles have a mixture of white and brown body feathers, with black wingtips. The adult plumage is attained in about one year. They are the tallest birds in North America.
Females are slightly smaller.
Yet these huge birds weigh only 11-16 pounds. Their long necks are extended straight forward in flight, with legs extended beyond the tail. The wingbeat is slow. A. Whoopers are white and larger than the common sandhill cranes, which are light gray. Whoopers migrate in groups of usually 2 to 7, whereas sandhill cranes migrate in flocks of 2 to hundreds.