Another African bird, namely, the 'Buphaga Africana', attends the rhinoceros for a similar purpose. It is called "kala" in the language of the Bechuanas. When these people wish to express their dependence upon another, they address him as "my rhinoceros", as if they were the birds. The satellites of a chief go by the same name. This bird can not be said to depend entirely on the insects on that animal, for its hard, hairless skin is a protection against all except a few spotted ticks; but it seems to be attached to the beast, somewhat as the domestic dog is to man; and while the buffalo is alarmed by the sudden flying up of its sentinel, the rhinoceros, not having keen sight, but an acute ear, is warned by the cry of its associate, the 'Buphaga Africana'. The rhinoceros feeds by night, and its sentinel is frequently heard in the morning uttering its well-known call, as it searches for its bulky companion. One species of this bird, observed in Angola, possesses a bill of a peculiar scoop or stone forceps form, as if intended only to tear off insects from the skin; and its claws are as sharp as needles, enabling it to hang on to an animal's ear while performing a useful service within it. This sharpness of the claws allows the bird to cling to the nearly insensible cuticle without irritating the nerves of pain on the true skin, exactly as a burr does to the human hand; but in the case of the 'Buphaga Africana' and 'erythrorhyncha', other food is partaken of, for we observed flocks of them roosting on the reeds, in spots where neither tame nor wild animals were to be found.
The most wary animal in a herd is generally the "leader". When it is shot the others often seem at a loss what to do, and stop in a state of bewilderment. I have seen them attempt to follow each other and appear quite confused, no one knowing for half a minute or more where to direct the flight. On one occasion I happened to shoot the leader, a young zebra mare, which at some former time had been bitten on the hind leg by a carnivorous animal, and, thereby made unusually wary, had, in consequence, become a leader. If they see either one of their own herd or any other animal taking to flight, wild animals invariably flee. The most timid thus naturally leads the rest. It is not any other peculiarity, but simply this provision, which is given them for the preservation of the race. The great increase of wariness which is seen to occur when the females bring forth their young, causes all the leaders to be at that time females; and there is a probability that the separation of sexes into distinct herds, which is annually observed in many antelopes, arises from the simple fact that the greater caution of the she antelopes is partaken of only by the young males, and their more frequent flights now have the effect of leaving the old males behind. I am inclined to believe this, because, though the antelopes, as the pallahs, etc., are frequently in separate herds, they are never seen in the act of expelling the males. There may be some other reason in the case of the elephants; but the male and female elephants are never seen in one herd. The young males remain with their dams only until they are full grown; and so constantly is the separation maintained, that any one familiar with them, on seeing a picture with the sexes mixed, would immediately conclude that the artist had made it from his imagination, and not from sight.
DECEMBER 2, 1855. We remained near a small hill, called Maundo, where we began to be frequently invited by the honey-guide ('Cuculus indicator'). Wishing to ascertain the truth of the native assertion that this bird is a deceiver, and by its call sometimes leads to a wild beast and not to honey, I inquired if any of my men had ever been led by this friendly little bird to any thing else than what its name implies. Only one of the 114 could say he had been led to an elephant instead of a hive, like myself with the black rhinoceros mentioned before. I am quite convinced that the majority of people who commit themselves to its guidance are led to honey, and to it alone.