African Nature Notes and Reminiscences

by Frederick Courteney Selous

The range of the koodoo to the south of the Zambesi extends farther to the south and west than that of the sable antelope, but I think I am justified in saying that up to the time of the deplorable visitation of rinderpest in 1896, wherever, between the Limpopo and the Zambesi, sable antelopes were to be met with, there koodoos were also to be found, and outside of districts infested by the "tse-tse" fly, excepting amongst rocky hills, I have never met with the latter animals in any country where I was not able to gallop after them on horseback.

Living as they do in surroundings so very similar to those frequented by sable antelopes, I have never been able to understand why koodoos should have such much larger ears than the former animals. I have never been struck with the acute sense of hearing in koodoos as I have been in the case of the moose of North America, and I should scarcely think that this sense would often save them from the noiseless approach of such animals as lions or leopards, to which they very frequently fall a prey, judging by the number of the remains of koodoo bulls which I have found that had been killed by the former animals.

I have often wondered whether the large size of the ears observable in the African tragelaphine antelopes, which are all forests dwellers (with the exception of the situtunga, which lives in dense beds of reeds), may not be useful to them by enabling the males and females to hear one another's calls during the mating season. The large ears and exquisite sense of hearing of the moose, which is also a forest-dwelling animal, have undoubtedly been developed for the purpose of enabling the males and females to find one another in the breeding season, and not for protection against the attacks of wolves. I have frequently heard both koodoos and bushbucks calling by night and also in the early morning. The noise they make is a sort of bark or cough.

Antelopes inhabiting open plains are very gregarious, and in the daytime would always be able to find their mates by sight. I have never heard them making anything but low grunting noises. As it is often assumed by naturalists that all bush-haunting species of antelopes have very large ears, it is perhaps worth noticing that in the little blue buck and the red bush duiker of South-East Africa, which both live in dense jungle near the coast, the ears are very small; whilst in the steinbuck, on the other hand, which is always found in very open country and never in thick bush, the ears are very large—both long and broad.

The coloration observable in the different races of bushbucks inhabiting different localities, as well as in the situtunga and inyala antelopes, is, I think, very interesting and suggestive. It may, I think, be taken for granted that all the races of African bushbucks have been derived from an ancestral form which was both striped and spotted; but in the bushbucks found near the coast of the Cape Colony and Natal, the adult males are deep dark brown in colour, often absolutely devoid of any white spots or stripes on face or body, whilst the adult females are yellowish red, with only a few white spots on the flanks. Now these most southerly of the African bushbucks live in really dense bush, and often in deep ravines, where the sun never penetrates. Their habitat too being near the sea-coast, the climate must be damper than in the interior of the continent. In the northern parts of Mashunaland and along the Central Zambesi and Chobi rivers the bushbucks live in forest and bush which is seldom very dense, and through most of which the sunlight plays constantly. In these districts the males are, when adult, beautifully striped and spotted, and the ground colour of their coats is rich red and dark brown, the females being of a dark rich red and also well striped and spotted. The situtunga antelopes live (on the Chobi and Central Zambesi) in immense beds of reeds which are always of one dull monotonous greyish green or brown. The adult animals are, as might be expected by those who believe in the direct influence of environment, of a uniform light brown colour, except that the spots on the cheeks and the arrow-shaped mark across the nose, present in most tragelaphine antelopes, are still discernible. In the inyala antelope, which inhabits thick jungly tracts of bush along the south-east coast of Africa, the adult male is of a deep dark grey in general body colour, with a few scarcely visible vertical white stripes. The young males and the adult females are, however, of a brilliant light red colour, profusely striped and spotted with white. The young of all bushbucks and of the inyala are reddish in ground colour, striped and spotted with white. The fœtal young of the situtunga found in the marshes of the Chobi are of the colour of a dark moleskin beautifully banded and spotted with pale yellow, and it is, I think, a very remarkable fact that these stripes and spots are identical in position with those found on the adult Chobi bushbuck, which is strong evidence, I think, that both these animals are descended from one ancestral form.

Now the only animal that preys habitually on bushbucks, inyalas, and situtungas is the leopard, and as leopards hunt by night and by scent, I cannot believe that the very different outward appearance of the various races of bushbucks inhabiting different parts of Africa is to be accounted for by the theory of protective coloration. The males and females of the Cape bushbuck and of the inyala antelope are very different one from another in the colour of their coats, but this does not seem to be prejudicial to either sex, though there is absolutely no difference in their habits or their habitat. In all the different races of bushbucks, however, with which I am acquainted, the males are much darker in colour than the females, so that it is not so very surprising that in the case of the inyala and the Cape bushbuck the males should have been the first to lose their stripes and spots in a sombre environment. In the case of the Cape bushbuck the adult females have already lost all the stripes and most of the spots of the ancestral form. The female inyala is, however, one of the most distinctly striped and spotted representatives of the tragelaphine group.

I cannot see that facts support the opinion that the uniform dull brown coloration of both sexes of the southern race of situtunga has been brought about for the purpose of protection from carnivorous enemies. During the daytime these animals live in the midst of beds of reeds growing in water where they cannot be approached except by wading; but at night they are often killed by leopards, and perhaps sometimes by lions, whilst feeding just outside the reed beds, on open ground which has perhaps been recently swept by a veld fire, and where young reeds and grass are just sprouting. At such a time their actual colour can be of no more use in the way of protecting them from their keen-scented feline foes than if it were black or red or grey. To me it seems far more probable that the situtunga has gradually lost the stripes and spots of the ancestral form from which it is derived, and assumed a uniform dull brown coloration, because it has lived for ages amongst reed beds of one dull monotonous colour, than because a uniform brown coat affords it a special protection against carnivorous foes.

I gather from the writings of Mr. A. R. Wallace and other well-known naturalists that, whereas the coloration of all animals is supposed to be due to the need of protection from carnivorous beasts, many species have developed in addition what are known as recognition marks, to enable them to distinguish members of their own species from nearly allied forms, or to help them to quickly recognise and rejoin the members of the herd or family from which they may have been separated.

That many large mammals belonging to different genera, and living in widely separated parts of the globe, are marked with conspicuous patches of white on the rump, neck, or face, or throw up bushy tails when running, showing a large white under surface, is an indisputable fact, though it is not possible to say that the possession of such a conspicuous coloration is absolutely necessary to the well-being of any particular species, because there will nearly always be other species living in the same country, and subject to the attacks of the same predatory animals, in which these so-called recognition marks are absent. However, on the supposition that carnivorous animals hunt by sight, it seems to me that no animal can be said to be protectively coloured which is marked in any way so conspicuously as to be recognisable by others of its own species at a distance, for it would be equally recognisable by all predatory animals, and caribou and white-tailed deer or African antelopes cannot escape from wolves or wild dogs by running like rabbits into burrows.

Personally, I cannot see why large antelopes which live in herds on open plains should require special recognition marks, as in such localities the bulk of an animal's whole body would be plainly visible at a great distance no matter what its colour might be. If an antelope became separated from its fellows by night, all so-called recognition marks would be invisible at a very short distance. It must be remembered, however, that every species of animal has a peculiar and very distinctive smell of its own, and my own observations would lead me to believe that most wild animals recognise one another, as a rule, more by scent than by sight.