The eagle is one of the largest and most powerful birds in the world. Some eagles weigh as much as 12 or 13 pounds and have a wingspan of about seven feet. The nests of eagles are called eyries. They are built mainly of sticks and are often lined with fresh green leaves while they are being used. Once a year, the female lays one or two eggs, and they are carefully tended, sometimes even by the male eagle, until they hatch, in about 40 days. Both parents then guard the nest and take food to