About Rhinoplax vigil (Pennant, 1781)
This bird species has mostly blackish plumage, with only the belly and legs being white. Its tail is white, with a black band near the tip of each feather. The tail is long, and its two central tail feathers are much longer than the rest. This makes the bird's total length longer than that of any other hornbill species. Its body length measures 110–120 cm (43–47 in), not including the tail feathers, which add an extra 50 cm (20 in) to the total length. One recorded male weighed 3.1 kg (6.8 lb), while two recorded females averaged approximately 2.7 kg (6.0 lb). Although this species is sometimes considered the largest Asian hornbill, its average body weight appears similar to that of the great hornbill, and is considerably lower than the body weight of African ground hornbills. This species has a bare, wrinkled throat patch: the patch is pale blue to greenish in females, and red in males. Its casque extends from the base of the bill halfway to the tip, where it ends abruptly. Both the casque and the bill are yellow; red secretion from the preen gland covers the sides and top of the casque and the base of the bill, but often leaves the front end of the casque and the distal half of the bill yellow. Unlike the casques of other hornbills, the helmeted hornbill's casque is solid, and the skull including the casque and bill can make up 10 percent of the bird's total body weight.
