Wrinkled Hornbill
(Aceros corrugatus)
Wrinkled Hornbill
(Aceros corrugatus)
Classification and Range
Hornbills are classified in the order Coraciiformes, which includes
kingfishers, todies, motmots, bee-eaters, rollers, hoopoes and other
related species. The 54 species of hornbills are further classified
into the family Bucerotidae. There are two subspecies of wrinkled
hornbills: A. c. corrugatus and A. c. megistus.*
The wrinkled hornbill ranges from southern Thailand through Peninsular
Malaysia, and the islands of Sumatra and Borneo.
Habitat
Wrinkled hornbills inhabit lowland primary evergreen forest. As with
other hornbills, they are nomadic, covering large areas between
foraging areas and roosts.
Physical Characteristics
The adult male’s crown, back of neck, body and wings are black. Its
face and front of neck are whitish-yellow, and the tail is white with
a broad, black base. The male’s bill is yellow with a red-brown base
and ridges across the lower mandible. The bill features a deep-red,
tall, wrinkled ridge (also called the casque ridge) on the upper
mandible near the eyes. The skin around the male’s eyes and the
inflatable, bare throat skin are pale yellow. Eyes are red, while legs
and feet are blue-gray.
The adult female is smaller than the male, with similar black coloring
on the head, face and neck. The female’s casque has a low profile and
the bill is pale yellow with orange at the base. In contrast to the
male, the female’s facial skin is blue, her eyes are brown, while the
legs and feet are blue-gray.
Both sexes of immature wrinkled hornbills have plumage like the adult
male. However, their casque ridge is undeveloped and the bill is pale
yellow with orange at the base. Juveniles have pale yellow facial
skin, yellow-colored eyes with a brown tinge, and blue-gray legs and
feet. Immature females molt into their adult face and neck colors at
approximately 1 year of age. The juvenile male’s plumage remains the
same.
Life Span
Life expectancy in the wild could be approximately 20-30 years.
Researchers need information from long-term banding studies to
accurately know life expectancy.
Historical records of wrinkled hornbills in captivity provided
misleading information, as husbandry issues were underdeveloped and
birds died after just a few years. Presently, the oldest living bird
in captivity is a wild-caught male that a zoo acquired in 1989.
Because it was wild-caught, its exact age is unknown. Life expectancy
in captivity probably exceeds that of wild birds. With improved
husbandry, more information on longevity will become available on
captive-hatched birds.
Diet
In the wild: Various fruits (especially figs) are the major part of
their diet. Wrinkled hornbills also eat small vertebrates and
invertebrates as a small part of their diet.
At the zoo:
Apples, papayas, bananas, grapes, blueberries, pear, melon and cooked
yams. Some wrinkled hornbills also get juvenile mice twice weekly.
Reproduction
Wrinkled hornbills probably reach sexual maturity at 5-6 years. In
Thailand, the breeding season normally occurs from January to June.
North American captive births result in hatchings between February and
August. If the first clutch fails, the birds will re-nest and try
again.
The birds find a natural cavity (caused by lightning strikes, natural
decay, etc.) in a large tree and the female seals herself inside. She
creates a mixture of feces, food, and feathers into a clay-like
substance to seal off the enclosure. A narrow vertical slit in this
hard wall provides space for the female to defecate and the male to
regurgitate food to the female (and nestlings). She remains inside the
nest, incubating two to three white eggs for approximately 30 days.
During incubation, the female depends entirely on the male to provide
her with food. After hatching, the female remains in the nest,
brooding the chicks for another 65-73 days.
Life Cycle
The chicks emerge from the nest with the female, or a few days after
she has exited the nest cavity. After confinement inside the cramped
nest for about 10 weeks, the fledglings are not strong flyers. It
takes a day or two of exercising their muscles to enable fledglings to
keep up with their parents. Parents continue to feed the juveniles as
they forage together in the forests.
In the tropics, food resources vary with space and time. Not all trees
provide fruit during the same period of time and these fruiting trees
often grow far apart. During the non-breeding season, large groups of
hornbills may feed together in the same tree. Eventually, juveniles
begin eating on their own. Adults return to the nest in the next
breeding season, leaving immature and unpaired birds to roam among
fruiting trees.
Toucan or Hornbill?
While toucans and hornbills share many physical characteristics, they
are two completely different families of birds. Many people look at
hornbills and immediately call them “the Fruit Loops toucan.” This
confusion is understandable. Both groups of birds have long, sometimes
colorful bills. They both nest in cavities in tropical regions, and
feed predominantly on fruits. However, this is where the similarities
end.
Toucans live only in Central and South America; hornbills live only in
Africa and Asia. Toucans are more closely related to woodpeckers,
while hornbills are more closely related to kingfishers. The similar
appearance of toucans and hornbills is an excellent example of a
phenomenon called parallel evolution. This theory hypothesizes that
two or more different species from different families and
geographically separated locations have adapted similarly to fit an
available niche in nature.
An Impenetrable Bond
Because the female depends so much on the male to provide (food) for
her and the nestlings, courtship occurs throughout the year to build
and maintain strong pair bonds. The male and female invest much time
developing this bond, so it is to their advantage to remain together
year after year, returning to the same nest site to breed and raise
their young.