Size: L: 55-65 cm. Wt: Males: 1400 g. Females: 1550 g. Males and females are dimorphic in size, and somewhat dimorphic in colour. This species is not seasonally dimorphic.
Adult Male: mantle dark brown; head white, crested, with dark brown eyestripe running onto neck; underparts white; tail rounded, and barred brown and buff; bill hooked, black, with dark grey cere; legs pale grey, with large, taloned feet
Adult Female: similar to adult male, but slightly larger, and with a brown band of speckling across breast
Juvenile: similar to adult, but edges of mantle feathers whitish, giving scalloped appearance; underparts buffier
Nestling: semialtricial and downy; first down thick, smoky brown above, with a buffy streak down centre of head and back; whitish below; second down similar, but dorsal streak whitish; whitish below, with brown tips on feathers; bill hooked, black with yellow gape; feet yellowish