HOOK-LIPPED OR BLACK RHINOCEROS 643 
either on their sides or in a kneeling position. They not 
only fed on the thorny, partially leaved twigs—the black 
rhino is a browser, whereas the white rhino is exclusively 
a grazer—but also fed greedily in the bare plains on the 
low-growing, shrubby plants, only a few inches high, with 
woody stems. I do not believe that they were really graz¬ 
ing, but together with the shrub stems they cropped they 
swallowed the tough jointed grass. They also ate aloes 
and a kind of prickly euphorbia with a blistering juice; it 
is hard to understand how even their palates could stand 
the thorns and the acrid sap. We saw them feed at noon; 
once we stumbled on one feeding by moonlight; but their 
favorite feeding times were in the morning and afternoon. 
Like other game, rhinos are assailed by various insect 
pests. Biting flies annoy them much; even when resting 
their ears are usually in motion to drive away their winged 
assailants. The ticks swarm on them; loathsome creatures, 
swollen with blood, which might be so crowded under the 
armpits, in the groin, and in the soft parts generally that 
they looked like mussels on an old dock. We do not quite 
understand why the tick-birds fail to keep down these ticks. 
These tick-birds, rather handsome, noisy creatures, are in 
most places the well-nigh invariable attendants of rhinos 
when the latter dwell on the plains or in fairly open bush. 
They clamber all over their huge hosts, like nuthatches 
round a tree trunk, and usually go in flocks. So invariably 
are they attendants upon the big game that if we heard 
them chattering as we threaded our way among bushes we 
were always at once on the alert to see a rhino. Sometimes 
they are wary, and chatter and fly off on seeing the hunter; 
at other times they pay but little heed; and the rhino may 
