Size: L: 65 cm. Wt: 700-1000g. Males and females similar. Adult plumage attained in third year.
Breeding: black crown, bill and back; white plumes on back of neck; breast, forehead and cheeks white; neck and wings grey; feet greenish-yellow.
Second Year: crown and back brownish-black; rest of body brown; underparts with faint streaking.
Juvenile: head and back chestnut, with varying amounts of whitish streaking; bill with some yellow, mostly on lower mandible; underparts streaked brown and whitish.
Nestling: semialtricial and downy; down sparse, with that on crown being stiff and erect; down absent from parts of head, hind-neck, and belly; down reddish-brown above, white on thighs; bill grey; legs and feet greyish-green; iris greyish or greenish, becoming golden-yellow