Head, neck, part of belly and underwing is bare. Parents brood chick continuously. May begin to wander outside nest as early as 8 weeks. Juvenile feathers appear at about 18 weeks. Fully developed plumage appears at 24-25 weeks.
Beak color is dark gray.
Birds 2 to 4 years. Skin of head and neck is dark. Wing lining varies from mostly blackish to white mottled. Iris of eye is dark olive-brown. At the beginning of 3rd year, neck has a pink ring.