The following are the dimensions of three fine males (changed to cm; Ed.):- Length, 81 to 83; expanse, 130 to 132; tail, 17 to 19; wing, 34 to 34.5; tarsus, 5.8 to 6.1; bill, from gape 9.8 to 10; outer toe and claw, 9.6 to 10.1.

The under surface of the plumage, from the throat to the vent, varies in individuals from glossy black to pure white, and every possible combination of the colors occurs.

Iris, bright green; pouch and under the eye, bright gamboge yellow; eyelids and in front of eye, dusky yellow; the culmen and on either side dark brown; the tip and margin of the upper mandible, together with the whole lower one, light pinkish horny; legs, toes and claws deep glossy black.