A Bird That Chooses Imprisonment
Tropical and subtropical areas in Asia and Africa are the home of the hornbill. This dark-colored bird looks as though it is greatly handicapped by its huge beak. And when the female is walled up in the hollow of a tree, with only a hole large enough for her to project the tip of her bill, a person may well conclude that something definitely has gone wrong.
Appearances, though, can be deceptive. Filled with many air chambers, the awkward-looking beak is comparatively light and just right for hornbills. Perched on a branch that is strong enough to support the weight of its body, the hornbill makes good use of the long beak to reach fruit.
For quite a few weeks the females of most varieties live in confinement and are fed regurgitated food by the males. Females of at least one variety, using a mixture of clay, dung and food particles, hammer the wall into place, and males obligingly bring the needed clay.
The confined female is undisturbed as she incubates her eggs. While walled up, she loses her tail feathers and wing feathers, making it impossible for her to fly until they are replaced. So her self-imposed imprisonment serves as a protection.
The male is kept very busy in caring for his mate and offspring. During the course of an hour he may visit the nest 20 times to supply food. Once the hatched birds have an appetite that is too much for him to handle, the fully feathered mother breaks free and begins helping her mate to feed their offspring.
The youngsters proceed to close up the enlarged opening through which their mother exited. But as time passes, a conflict of interests may arise. Some of the birds may be ready to leave the nest, while others may not be. So while one youngster begins breaking down the wall, another one is right on the job doing the repair work.
Truly, careful observation and research time and again reveal that seemingly strange features and habits of animals serve a good purpose. Hornbills, with their long beaks and extraordinary nesting procedures, are not an exception.