Hornbills are very unusual looking birds.
There are 54 species of hornbill in the
world. They have some of the most
impressive beaks in size, shape, and color. Even more fascinating are their courting displays and
unusual nesting habits. Their
range extends from Africa across India and Asia to Papua New Guinea in the
southeast Pacific Ocean.
The very colorful Knobbed Hornbill, native to
tropical evergreen forests of Indonesia.
Hornbills are characterized by long down-curved beaks which
help them to reach food in tree branches.
Unique to most species of Hornbills is a large outgrowth on the upper
beak called a casque. This structure
is hollow and made of keratin (the same substance that composes our own hair
and fingernails), with the exception of the Helmeted Hornbill where the front
end of the casque is solid ivory.
Their skull makes up 10% of the adult birds weight.
Helmeted Hornbill, native to evergreen forests
of Southeast Asia.
Hornbills are the only birds in which the first two neck
vertebrae are fused together in order to provide a more stable platform for
carrying their large bill. The
casque is larger in adult males and can assist in dominance displays and
attracting mates. In fact, a few
species will undergo aerial “jousting.”
Helmeted Hornbills for example may joust to compete for food, territory
or mates. They fly towards each
other and smash their casques together creating a loud clacking noise. They may flip upside down or be pushed
backwards from the force that is created.
The collisions may occur repeatedly and may last up to 2 hours.
Hornbills studied so far breed as monogamous pairs. With the exception of ground hornbills,
the female will lay her eggs in a tree cavity. She will then seal up the hole using mud, leaving enough
room for her to climb inside. The
remainder of the opening will then be sealed by the female using feces and
regurgitated food, leaving only a small opening for the male to pass
regurgitated food to his mate and their chicks. While inside the females of some species will molt all of
her flight feathers as she incubates the eggs. Sealing the cavity of course protects the nest from predators,
but in turn causes problems of sanitation in the nest, and a lot of work for
the male. Young of the previous
year have been seen to help the males with feeding. In some species of hornbill, when the chicks are half grown,
the female will break out of the nest cavity. The chicks will re-seal themselves in and the parents will
continue to feed them until they are ready to fledge.
Many species of hornbills are threatened or endangered. Habitat destruction and hunting are
among the biggest threats. Some
are in danger of being captured for the exotic pet trade. Many hornbills are killed for their
casques, which are used for carvings and traditional medicines. In Sarawak, Malaysia, local people hunt
the hornbills for their feathers, which are used for headdresses and
ceremonies. Luckily however,
ceremonial leaders have agreed to receive shipments of molted hornbill feathers
from zoos.
If you want to help
endangered birds, you can help by simply visiting us and spreading what you’ve
learned, becoming a member or friend, or adopting-a-bird, which feeds that bird
for a year!
Submitted by Sara Oliver, World Bird Sanctuary Naturalist
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