The eastern great egret (Ardea alba modesta), a white heron in the genus Ardea, is usually considered a subspecies of the great egret (A. alba). In New Zealand it is known as the white heron or by its Māori name kōtuku. The subpecies was first described by British ornithologist John Edward Gray in 1831.
Measuring 83–103 cm (33–41 in) in length and weighing 0.7–1.2 kg (1.5–2.6 lb), the eastern great egret is a large heron with all-white plumage. Its bill is black in the breeding season and yellow at other times,and its long legs are red or black.[citation needed] The colours of the bare parts of the face change to green during the breeding season. The breeding plumage is also marked by long neck plumes and a green facial area.The eastern great egret can be distinguished from other white egrets and herons in Asia and Australia by its very long neck, one and a half times as long as its own body.