The whooper swan is a large type of waterfowl, whose adults reach lengths of up to 140cm, with wings as long as 60cm each. While their bodies are predominantly white, some feature yellowish markings on the head and neck. There are no color differences distinguishing males and females, but cygnets younger than one year old are gray with brownish streaks, the area around the top of the beak a pinkish white. Also, adults can weigh more than 10kg, which is quite heavy for a flying animal. Take-off requires the assistance of a run-up. Whooper swans feed mostly on the stems and roots of aquatic plants, and their main breeding ground is northen Eurasia, Iceland, etc.