A great hornbill mother walls herself inside a tree for months
When a female great hornbill nests, she seals herself into a hollow tree trunk with a plaster made largely of droppings. For weeks her mate feeds her through a narrow slit while she moults every feather. Only when the chicks are half grown does she break out, and the chicks promptly seal themselves back in.
The great hornbill is the heaviest typical hornbill, weighing two to four kilograms with a wingspan around 1.5 metres. Its trademark is the yellow and black casque perched on its huge bill, U-shaped from the front with two ridges ending in points, hence the name bicornis, two-horned. The casque is hollow and has no known use, though sexual selection is suspected, and males sometimes bash casques together in mid-air. The bright yellow comes partly from a preen-gland oil males smear on their bills and feathers. Wingbeats are so heavy that a passing bird sounds like a steam engine pulling away.
It lives in the old-growth hill forests of India, Nepal, Bhutan, mainland Southeast Asia and Sumatra, and depends on large tracts of rainforest. Fruit, especially figs, makes up most of its diet and supplies all its water, which makes it an important seed disperser. It also hops along branches hunting lizards, nestlings and insects, tossing prey in the air before swallowing, and has taken small owls. Pairs are monogamous and duet loudly in the breeding season, from a steady male call into a blend of roars and barks.
Chicks hatch with no hint of a casque, and it takes five years to develop fully. Birds roost punctually at sunset along the same routes each day, sleeping with bills tilted skyward. In captivity one has lived nearly 50 years, but breeding there has succeeded fewer than a dozen times, partly because they are so choosy about partners.
Deforestation and hunting for meat, feathers and casques have made it vulnerable, and it is listed in CITES Appendix I. Conservationists have offered tribes feathers from captive birds and ceramic casques as substitutes. Kerala and Arunachal Pradesh both chose it as state bird, and a hornbill called William, who lived 26 years in a Bombay office, became the Bombay Natural History Society's emblem.
Source: Great hornbill
