THE BIRDS OF LIBERIA 687 
Ceratogymna elata (Temminck). Yellow-casque Hornbill; ‘‘Palm-bird”’ 
Buceros elatus Temminck, Pl. Col., livr. 88, pl. 521, fig. 1, 1831: Sierra Leone. 
A very large bird, length 35 inches; the male black with steely reflections, the outer tail- 
feathers white; skin of throat from below eye to basal third of large dew-lappet black, tip of latter, 
chin, and ring around eye blue; iris red. Female with a smaller casque, the head dull reddish. 
Portuguese Guinea to northern Cameroons. 
This fine great bird is common in the Liberian forests and by reason of its 
size and loud notes at once attracts attention. At our first camp on the Du 
it was daily seen, usually a pair or single birds flighting across the clearing 
from one part of the forest to another. Three birds, probably a pair and a full- 
grown young, came daily at various times to a great silk-cotton tree by the 
river’s edge, and there was some evidence that it contained a nesting cavity 
in a large hollow limb. The manner of flight is most characteristic, consisting 
of several powerful downward strokes of the wings with a considerable ampli- 
tude below the level of the body, followed by a long sail with set wings, on a 
shght downward course, when presently the powerful wing-strokes are repeated, 
followed by another long, slow sail, and so on until the bird has reached its 
destination. Frequently the number of wing strokes would be but four be- 
tween the long sails, but sometimes, more, and occasionally I counted as many 
as eighteen or twenty beats. Such is the force of the wing-beat that the swish 
of the air rushing between the expanded tips of the primaries may be heard 
for a considerable distance, and often as one stands among the great trees in 
the silence of the forest, it is all that apprises one of the passage of the bird. 
The neck is carried stretched out in front in flight, and as the wings flap, the 
tail opens and shuts in a most grotesque manner, giving the impression that 
the bird is coming apart with the exertion of flight. Very often I noticed that 
the male bird of a pair, easily distinguishable by the larger casque with a pro- 
jecting horn, slightly preceded the female when the pair were flying together. 
The note, far from resembling the braying of a donkey as Johnston puts it, 
is a hoarse raven-like croak, or when perched in a tree, a low cawing much 
like that of a young crow. On August 16, Coolidge and I saw a nearly grown 
young bird with the male parent, perched on one of the upper branches of a 
great tree by the Du. The young bird’s head was still downy and it flapped 
its wings in a begging attitude, at the same time giving a faint cawing note. 
The stomach of the large male shot, held two large fruits each with a stone, 
about the size of peaches, having a coarse yellow pulp. Buttikofer notes that 
it feeds on the fruits of several large kinds of forest trees and when the oil- 
palm nuts are ripe, in February and March, it is fond of them too, whence it 
has acquired the local name of ‘ Palm-bird.’’ He further records, which we 
did not see, that the small family parties may at times gather into large flocks, 
and describes a roosting-place where the birds came in to spend the night among 
small trees, perching from ten to twenty feet above the ground. They were 
quick to abandon it, however, on being disturbed, and in general are rather 
wary birds. A tame young bird that Bittikofer kept, had to be fed on fruit 
for about two months before it was able to take food for itself. It slept with 
