African Nature Notes and Reminiscences. Frederick Courteney Selous
conspicuous in winter. Of the predatory animals the large timber wolves are, as a rule, pale greyish brown with black hairs on their backs and shoulders, but a considerable number are quite black; the foxes are either red or black, or of the intermediate coloration known as "cross"; whilst the wolverines, martens, and minks are rich dark brown, and the lynxes neutral grey. The stoat or ermine is the only carnivorous animal which turns white in winter in these countries.
It would thus appear that in the sub-Arctic Regions of North America the coloration of mammals does not obviously serve the purpose of concealing the herbivorous species from their enemies, or of enabling carnivorous animals to approach their prey unperceived. To come nearer home, we find that whereas in the Alpine regions of Europe the mountain hare turns white in winter, the chamois living in the same snow-covered ground becomes deep black. It is true that in winter chamois often leave the open mountains and live amongst the higher forests, where it may be said that their dark colour harmonises well with the dark foliage of the spruce trees; but I have hunted chamois in December in the mountains of Transylvania, when they were in full winter coat, and I certainly found that their dark coloration often made them conspicuous.
Turning to Africa, we have many instances of what seen in the open and at short range cannot possibly be called anything but conspicuous coloration, such as the jet black and pure white striping of the East African form of Burchell's zebra; the deep glossy black body and neck, with snow-white belly and parti-coloured face, of the sable antelope; the black and white face of the gemsbuck; the pure white face and rump of the bontebok, combined with the beautiful dark brown neck and sides and lilac tinted back; or the juxtaposition of the black and white in Thomson's gazelle—only to mention a few of the most noteworthy examples.
To me it seems that the influence of environment might very well be deemed sufficient of itself to cause all animals that have lived for long ages in treeless deserts under constant strong sunlight to assume the dull brown coloration which they undoubtedly possess; whilst Arctic conditions might be expected to cause the whitening of an animal's hair in the winter, or the play of the sun's light through the leaves and branches of trees and bushes to be responsible for a spotted or striped coat. In the case of a combination of black and white—the two most conspicuous colours in nature—such as may be seen in the adult cock ostrich or male sable antelope, why should it not be supposed that the law of sexual selection has come into play, as it probably has done in the production of the lion's mane and the exaggerated size of the horns in the male koodoo.
Having spent many years of my life in the constant pursuit of African game, I have certainly been afforded opportunities such as have been enjoyed by but few civilised men of becoming intimately acquainted with the habits and life-history of many species of animals living in that continent, and all that I have learnt during my long experience as a hunter compels me to doubt the correctness of the now very generally accepted theories that all the wonderfully diversified colours of mammals—the stripes of the zebra, the blotched coat of the giraffe, the spots of the bushbuck, the white face and rump of the bontebok, to mention only a few—have been evolved either as a means of protection from enemies or for the purpose of mutual recognition by animals of the same species in times of sudden alarm. Sexual selection and the influence of environment must, I think, have been equally potent factors in the evolution of colours in mammals, birds, reptiles, and insects.
In all recent articles which I have read by well-known naturalists on these subjects, it appears to be assumed that both carnivorous and herbivorous animals trust entirely to their sense of sight, the former to find their prey, and the latter to detect and avoid the approach of their enemies. Yet nothing is more certain than that all carnivorous animals hunt almost entirely by scent, until they have closely approached their quarry, and usually by night, when all the animals on which they prey must look very much alike as far as colour is concerned.
The wild dogs of Africa and the wolves of northern latitudes are not so completely nocturnal, it is true, as the large Felidae, but the former I know, and the latter I have every reason to believe, hunt, as a rule, by night and only occasionally in the daytime. In both these animals the sense of smell is enormously developed, and must be of far greater use to them in procuring food than the sense of sight, however acute that may be. In all my wanderings I have only seen African wild dogs chasing game in the daytime on four occasions. I once saw a single wild dog chasing a sable antelope in the daytime. This wild dog—which was, however, then too far away to enable me to see what it was—first ran past the sable antelope and behind it from where I was watching. It must then have been running on the trail, with its nose on the ground, and must have passed quite close to the animal it was pursuing without seeing it. Its nose, however, kept it on the antelope's tracks and soon brought it to close quarters, and then of course it continued the chase by sight. Now if this is the usual proceeding of African wild dogs, and I am convinced that it is, the value of assimilative coloration to animals on which the wild dog preys cannot be very great.
But not only do all carnivorous animals hunt by scent, and rely far more upon their olfactory organs than upon their keenness of sight to procure food, but, as all practical hunters very well know, the sense of smell is also very highly developed in all, or at any rate in most, of the animals on which the carnivora prey, and personally I am persuaded that all browsing and grazing animals in Africa trust as much to their noses as to their eyes both to avoid danger and to find members of their own species. The eyes of antelopes are quick to detect a moving object, but they are by no means quick to notice any unusual colour in a stationary object. I will relate an anecdote illustrating this point.
Early in 1883, I reached the spot on the Hanyani river in Mashunaland where I intended to establish my hunting camp for the season. Whilst my Kafirs were chopping down trees to build the cattle enclosures, I climbed to the top of the ridge at the foot of which I was having my camp made.
It was late in the afternoon, and I was sitting on a rock looking over the open country to the south, when I heard a slight noise, and turning my eyes saw a fine male waterbuck coming towards me up the ridge. I sat perfectly still, and it presently walked slowly past within three yards of me and then went on along the ridge, into the forest beyond. As it passed me I noticed its shining wet nose, and the way in which its nostrils kept constantly opening and shutting at every step. It was evidently listening to the noise that my Kafirs were making chopping down small trees at the foot of the ridge, but as it could not get their wind did not take alarm.
Of course, if I had made the very slightest movement, this waterbuck would have seen me instantly; but had it possessed much sense of colour, the contrast between the red brown of my sunburnt arms and face and the light-coloured shirt I was wearing would have attracted its attention, as I was sitting on a stone, on the top of a ridge which was quite free from trees or bush. I have never had any other African antelopes pass so close to me as this without seeing me, but many have fed slowly past me, as I sat watching them, with a tree or a bush behind me but nothing between myself and them, at distances of from 20 to 50 yards.
Both in Newfoundland and in the Yukon Territory of Canada, I have had caribou walk almost over me when sitting in front of them on their line of march on ground devoid of any cover whatever. In such cases, of course, the wind was blowing from these animals towards where I was sitting, and I remained absolutely motionless.
As a rule, when wild animals notice something suspicious approaching, say a man on horseback, and cannot get the scent of it, they run off before it gets near them or circle round to try and get the wind of it. But the smaller African antelopes, steinbucks, duikers, oribis, and reedbucks will occasionally, while keeping their eyes fixed on the unfamiliar object, crouch slowly down, and then, with their necks stretched along the ground, lie watching. I have ridden past a few oribis, steinbucks, and reedbucks within a few yards, as they lay absolutely motionless on the ground watching me. To pull in one's horse with the intention of shooting such a crouching antelope was the instant signal for it to jump up and bound away. Lions too, when they see a human being and imagine that they themselves have not been observed, will often lie flat on the ground watching, and will not move until very closely approached. I imagine that these carnivora secure nearly all their prey by approaching herds of game below the wind, and when they have got pretty near lying flat on the ground, perfectly motionless except for the twitching of the end of their tails, which they never seem