Rhinoceros Hornbill Buceros rhinoceros Classification ... - Denver Zoo

Distinctive Casque
The distinctive casque on top of their bill looks heavy and cumbersome. Composed of keratin
overlying bony support, the casque is very strong and relatively lightweight. The casque is used in
recognizing the age, sex and species of the hornbill. It also acts like a resonating chamber that
amplifies their loud squawks.
Conservation Connection
IUCN Status: Near Threatened.
Rhinoceros hornbills are listed as near threatened due to loss of habitat, poaching for their feathers and
hunting for food.
Fun Facts
• When flying, the wings of the hornbill make a loud humming sound that can be heard up to 65 feet
away.
• Males have red eyes and females have white eyes.
• Hornbills have very long eyelashes that protect their eyes from injury. The eyelashes are actually
modified feathers.
• Hornbills are the only birds that have the first two neck vertebrae fused together. Along with strong
neck muscles, the fusion of the vertebrae helps support the weight of their large bill and casque.
• While enclosed in the nest chamber, the female undergoes a simultaneous molt of all flight and tail
feathers. She grows new feathers by the time she emerges from the nest.