The Great Egret lives for about 15 years, has an average mass of only 1 kg and a wingspan up to 1.7 m. It was almost wiped out at the end of the 19th century as its feathers were used to decorate ladies hats. It migrates south from the Northern Hemisphere during the colder months. Males and females look identical. They love to build their nests up high in trees that are at least 20 m tall.