African Nature Notes and Reminiscences 8
As a rule, lions do not commence to hunt before darkness has set
in. They then seek their prey by scent, either smelling the animals
directly or following their tracks. They understand as well as the most
experienced human hunter the art of approaching game below the wind,
when hunting singly; but when there are several lions hunting together,
I believe that some of them will sometimes creep close up to a herd of
game below the wind, whilst one or more of their number go round to the
other side. The buffaloes, zebras, or antelopes at once get the scent
of these latter, and run off right on to the lions lying waiting below
the wind, which then get a good chance to seize and pull down one of
the frightened animals. As lions have played this game with my cattle
upon several occasions, I presume that they often act in the same way
with wild animals.
No matter how dark the night may be, a lion has no difficulty in
seizing an ox, a horse, or a donkey exactly in the right way, and I
have no doubt that he does the same in the case of all the different
kinds of game upon which he preys. Now that the buffaloes have been
almost exterminated by the rinderpest in most parts of Africa, the
zebra undoubtedly forms the favourite food of the lion. For every zebra
that is killed by daylight probably at least a hundred are killed
during the night, when, except by moonlight, they would appear to a
lion very much the same, as far as coloration goes, as a black ox, a
dark grey wildebeest, or a red hartebeest, all of which animals look
black by night if they are near enough to be seen at all.
I have had innumerable opportunities of looking at wild zebras, and
when met with on open ground they certainly have always appeared to me
to be very conspicuous animals, except just at dawn and late in the
evening, when they are not so easy to see as animals of some uniform
dark colour, such as hartebeests.
In Southern Africa, between the Limpopo and the Zambesi rivers,
Burchell's zebras used to be very plentiful in all the uninhabited
parts of the country, and although they were often met with feeding
or resting in districts covered with open forest or scattered bush,
I found them always very partial to open ground, where they were as
plainly visible as a troop of horses. In East Africa the local race of
Burchell's zebra is remarkable for the whiteness of the ground colour
of the body and the intense blackness of the superimposed stripes.
These beautiful animals congregate in large herds on the bare open
plains traversed by the Uganda Railway, and probably form the chief
food of the lions living in that district.
When in East Africa a few years ago, I took special note of the
appearance of zebras at different distances on the open plains between
Lakes Nakuru and Elmenteita. I found that in the bright African
sunlight I could see with the naked eye the black and white striping
of their coats up to a distance which I estimated at about 400 yards.
Beyond that distance they looked of a uniform dark colour when the sun
was behind them, and almost white when the sun was shining on them.
But at whatever distance they happened to be on the open plain between
myself and the horizon, their forms showed up quite as distinctly as
those of a herd of cattle or horses. Never in my life have I seen
the sun shining on zebras in such a way as to cause them to become
invisible or even in any way inconspicuous on an open plain, and I
have seen thousands upon thousands of Burchell's zebras. Should these
animals be approached when standing amongst trees with the leaf on,
they are not at all easy to see, and the whisking of their tails will
probably be the first thing to catch one's eye; but in open ground,
and that is where they are usually met with, no animals could be
more conspicuous. I have seen zebras too by moonlight, but that was
many years ago, and I did not then take any special note of their
appearance; but my impression is that they were no more invisible than
other animals, but looked whitish in colour when the moon was shining
on them, and very dark when it was behind them. As, however, zebras
have a very strong smell, and lions usually hunt them by scent and at
night, I cannot think that their coloration, whether it be conspicuous
or not, matters very much to them, though I look upon the theory that
the brilliantly striped coats of these animals render them in reality
inconspicuous as absolutely untenable, as it is not in accordance with
fact.
When in East Africa I came to the conclusion that not only the zebras,
but also the impala antelopes--which are of a much richer and darker
red than in South Africa--were conspicuously coloured, and therefore
very easy to see; whilst the broad black lateral band dividing the
snow-white belly from the fawn-coloured side in Thomson's gazelles
showed these little animals up with the most startling distinctness on
the bare open plains they inhabit.
To my eyes, and in the bright sunlight of Africa, the juxtaposition
of black and white markings, so often seen on the faces of African
antelopes, has never seemed to produce an indistinct blur of colour
except at a considerable distance. At any distance up to 300 yards the
black and white face-markings of the gemsbuck, the roan, and the sable
antelope always appeared to me to be distinctly visible, and they have
often been the first parts of these animals to catch my eye.
It is all very well to say that a male sable antelope, in spite of
its bold colouring, is often very difficult to see. That is no doubt
the case, but that only means that there is no colour in nature, and
no possible combination of colours, which at a certain distance, if
stationary, would not be found to harmonise well with some portions
of, or objects in, an African landscape. Speaking generally, however,
the coloration of a sable antelope bull makes him a very conspicuous
object to a trained human eye, and also, one would suppose, to that of
a carnivorous animal, were it watching for prey by daylight.
CHAPTER II
FURTHER NOTES ON THE QUESTIONS OF PROTECTIVE COLORATION, RECOGNITION
MARKS, AND THE INFLUENCE OF ENVIRONMENT ON LIVING ORGANISMS
Occasional resemblance of African mammals to natural
objects--Hartebeests--Elephants--Giraffes--Coloration of
the Somali giraffe--Giraffes not in need of a protective
coloration--Koodoos and sable antelopes--Acute sense of hearing
in the moose--Possible explanation of large size of ears in
the African tragelaphine antelopes--Coloration of bushbucks,
situtungas, and inyalas--Leopards the only enemies of the
smaller bush-haunting antelopes--Recognition marks--Must
render animals conspicuous to friend and foe alike--Ranges
of allied species of antelopes seldom overlap--Hybridisation
sometimes takes place--Wonderful coloration of the
bontebok--Coloration distinctly conspicuous and therefore
not protective--Recognition marks unnecessary--Coloration
of the blesbok--The blesbok merely a duller coloured
bontebok--Difference in the habitat of the two species--The
coloration of both species may be due to the influence of
their respective environments--The weak point in the theory of
protective coloration when applied to large mammals--Hares and
foxes in the Arctic and sub-Arctic Regions--The efficacy of
colour protection at once destroyed by movement--Buffaloes and
lions--General conclusions regarding the theory of protective
coloration as applied to large mammals.
Certain observations have been made and theories propounded on the
occasional resemblance of African mammals to natural objects, which
have never seemed to me to have much significance, although they are
often referred to as valuable observations by writers on natural
history.
Thus it has been said that hartebeests, which are red in colour,
derive protection from their enemies owing to their resemblance not
only in colour but also in shape to ant-heaps, and that giraffes gain
an advantage in the struggle for life owing to the fact that their
long necks look like tree-trunks and their heads and horns like broken
branches.
Well, hartebeests are red in colour wherever they are found all over
Africa. Ant-heaps are only red when they are built of red soil. In
parts of the Bechwanaland Protectorate, where the Cape hartebeest used
to be common, the ant-heaps are a glaring white. In East Africa, in
different portions of which territory hartebeests of three species are
very numerous, all of which are bright red in colour, red ant-heaps
are certainly not a conspicuous feature in all parts of the country,
and there were, if my memory serves me, very few ant-heaps of any size
on the plains where I met with either Coke's, Neumann's, or Jackson's
hartebeests.[2] But even in those districts where the ant-heaps
are red in colour, and neither very much larger nor smaller than
hartebeests, they are usually of one even rounded shape, and it would
only be here and there, where two had been thrown up together forming
a double-humped structure, that anything resembling one of these
animals could be seen. Such unusual natural objects must be anything
but common, and cannot, I believe, have had any effect in determining
the bodily shape of hartebeests, though, if the coloration of animals
is influenced by their environment, red soil and red ant-heaps may have
had their influence on the colour of the ancestral form from which all
the various but nearly allied species of hartebeests have been derived.
[2] The plains along the railway line between Simba and Nairobi, the
open country between Lakes Nakuru and Elmenteita, or the neighbourhood
of the road between Landiani and Ravine Station.
I was once hunting in 1885 with a Boer friend (Cornelis van Rooyen)
near the Umfuli river in Mashunaland. We were riding slowly along,
followed by some Kafirs, and driving a donkey carrying corn for the
horses in front of us, when we saw what we took to be some boulders
of black rock in the open forest ahead, but some distance away, as we
were crossing an open valley at the time. In this particular part of
the country great boulders of black rock were a common feature in the
landscape. Suddenly our donkey pricked his ears, and stretching out his
nose, commenced to bray loudly. Immediately one of the black rocks,
as we had thought them to be, moved, and we soon saw that what we had
taken for rocks were elephants. Our donkey had smelt them before either
my friend or myself or any of our Kafirs had been able to distinguish
what they were. As, however, elephants are only occasionally
encountered in forests through which great boulders of black rock
are scattered, I do not believe that these huge quadrupeds have been
moulded to the shape of rocks by the need of a protective resemblance
to inanimate objects, any more than I think that the abnormal shape of
certain ant-heaps has had anything to do with the production of the
high wither and drooping hind-quarters of the hartebeest.
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