(_Buceros bicornis_)
The hornbills, which are as large as big eagles, are some of the most
extraordinary and bizarre of all birds, not only on account of the
huge beaks from which they take their name, but from their strange and
unique nesting-habits. In the enormous development of the beak these
Old World birds are paralleled by the toucans of tropical America,
although the two groups are in nowise nearly related. Such a huge and
apparently unnecessary structure might at first sight seem too heavy
and bulky for the bird by which it is carried; but internally the
beak is generally a mere delicate tissue of bone, so that its weight
is really very slight. Indeed, these enormous beaks are in most cases
probably much less of an incumbrance to their owners than are the
matinee hats favoured by ladies of the present day.
The pied, or double-horned species, the hornray of the natives,
inhabits the dense forests of the Indo-Malay countries from the
Himalaya and the Indian peninsula to the south of China and Sumatra.
The glossy plumage is mostly black above, with the under-parts, the
neck, the tips of the flight feathers, and the tail feathers more
or less white or whitish, the upper half of the huge beak, with its
horn-like appendage, being reddish yellow, and the lower half yellow.
The total length of the bird, which is the largest member of the
whole group, exceeds a yard. The so-called “horn,” or casque, forms a
more or less flat and oblong platform on the upper part of the beak
and the fore part of the head, terminating in front in two obtuse
corners. On the other hand, the same appendage in the nearly allied
rhinoceros-hornbill, or engan (_Buceros rhinoceros_), is much more
horn-like, as it turns up into a recurved point in front.
The range of the hornbill group includes Africa, India, Malaya,
Celebes, and New Guinea and the neighbouring islands as far as the
Solomon group. The ground-hornbills are solely African, while the
hollow-casqued section has a distribution equivalent to that of the
group. One very remarkable Malay species, the solid-billed hornbill,
the teban-mertua of the Malays (_Rhinoplax vigil_), differs from all
the rest in having the beak and casque solid. This species is much
hunted by the Chinese for the sake of its beak and casque, which have
a structure resembling ivory, and are used as a substitute for that
material in carving; while it is further remarkable for its bare neck
and the elongation of the middle pair of tail feathers.
[Illustration]
The flight of hornbills is heavy and noisy, the swishing sound produced
by the wings being audible at a great distance. The whole body of
these birds is permeated by air-tubes connected with the wind-pipe,
and it is said that the movement of the air in these increases the
noisiness of the flight.
Mountain-forests bordering valleys, and big forests near rivers, are
the favourite haunts of the typical hornbills. Here the great birds
perch in flocks which may number a score in individuals; for hours
together they sit motionless, with the neck drawn back on to the body,
and the body itself pressed down on to the feet.
Their food consists chiefly of the fruits of the trees in which these
birds take up their quarters, the favourite fruit being figs; but in
captivity hornbills will eat fruits of all kinds, as well as animal
food. These birds kill every small creature that comes in the way, and
throw them up in the air before swallowing the body. When perching,
hornbills utter from time to time a loud cry, recalling the bark of a
dog, this changing into a loud scream when they are wounded.
The most remarkable feature connected with the habits of these
birds is, however, connected with their nesting arrangements. As
was first observed in India in 1855 by a military officer devoted
to outdoor natural history, when the female has laid her clutch of
eggs, varying in number from two to half a dozen, in some hole in a
tree and commenced to incubate, the male walls up the entrance to the
apartment with clay, leaving an aperture only just large enough for
her to protrude her beak and receive the food brought regularly by her
hard-working mate. The object of this immuring process is doubtless
to protect the female and her eggs or young from the attacks of
birds-of-prey, or predatory arboreal mammals. Under these circumstances
sanitary matters cannot, of course, be attended to, and the nest-hole,
consequently, soon becomes an evil-smelling mass of abominable filth.
In order that no time may be wasted, the female moults during the
period of her confinement, a process which adds still more to the mess
in the hole. The young, which come forth from the eggs almost naked,
remain in the breeding-hole till they are fully fledged. To reach the
food brought by her partner, the female, at any rate during the early
stages of incubation, has to climb up to the aperture in the wall of
clay.