African Nature Notes and Reminiscences

by Frederick Courteney Selous

I am still quite unable to account for the sudden and rapid increase in the number of tse-tse flies along the waggon track between Leshuma and Kazungula between August and November 1888, as it is quite certain that up to the latter month they had taken no toll of blood from the cattle which had been driven backwards and forwards along the road either by night or during the cold weather in June or July.

I knew that my friend the late Dr. Bradshaw used to hold the view that the tse-tse fly deposited its eggs in buffalo dung, and I thought at the time that the cattle dung had been taken as a substitute. The very important researches, however, of Lieutenant-Colonel Bruce in Zululand have shown that "the 'tse-tse' fly does not lay eggs as do the majority of the Diptera, but extrudes a yellow coloured larva, nearly as large as the abdomen of the mother." The perfect insect does not hatch out for six weeks, so that the increase by generation from a small number of individuals in the course of a few months would not be very great. I can only think, therefore, that all the tse-tse flies throughout the bush through which the ten miles of road led from Leshuma to the Chobi must have been attracted to its neighbourhood by the smell of the cattle dung, which no doubt they mistook for that of buffaloes, the animals with which they have always been so closely associated in the countries to the south of the Zambesi. I am, however, not at all satisfied with this explanation.

I was obliged to keep my waggon standing on the bank of the Zambesi (waiting for ivory to be brought down from the Barotse valley) until late in November 1888, so that when I was at last able to send my oxen down to the river to bring it through the "fly," which now infested the waggon track leading from Leshuma to Kazungula in considerable numbers, the nights had become very warm, and although we did not start till after eleven o'clock, and ran the oxen to the river and brought the waggon back as quickly as possible, every one of them, twenty-one in all, got "fly-stuck" and died within six months.

After 1888 the tse-tse flies again rapidly diminished in numbers between Leshuma and Kazungula, and have long since absolutely ceased to exist there; so that here again we have another instance of a country in which, at no very distant time, both buffaloes and tse-tse flies literally swarmed, but from which both have now long since completely disappeared, although other animals, such as antelopes of various kinds and baboons, cannot yet be altogether extinct.

The same diminution and eventual disappearance of the tse-tse fly has also followed the extinction of the buffalo on the Okavango to the north of Lake N'gami.

As has been recorded by C. J. Andersson and other travellers and hunters, both buffaloes and tse-tse flies existed in great numbers along the Teoge (Okavango) river between Lake N'gami and Libèbè's in the early 'fifties of the last century. At that time the Batauwana tribe were living at Lake N'gami. These people gradually acquired firearms and drove the buffaloes northwards up the Okavango, and the fly did not long remain in the countries which these animals ceased to visit. In 1884, after having been twice attacked by the Matabele, the Batauwana abandoned their settlements at Lake N'gami and retreated several days' journey to the north along the Okavango, where they built a new town, which they named Denukani (on the river). From this point they have now been hunting through all the country farther north for more than twenty years, and I have been lately informed that a waggon road has been cut from Denukani to Libèbè's, and from thence to the Quito, the whole length of which is entirely free from tse-tse fly, which insects there seems every reason to believe have died out owing to the disappearance of the buffaloes from their former haunts.

But the facts which I have already stated, and which seem to me to show that in Africa to the south of the Zambesi there has always been a close connection between the buffalo and the tse-tse fly, by no means exhaust the evidence on this point.

When Sebitwane, the great chief of the Makololo, and Umziligazi, the founder of the Matabele nation, led their clans, the one to Linyanti between the Chobi and Zambesi rivers, the other to the high plateau near the sources of the Gwai and Umzingwani rivers, they found the whole country south of the Zambesi, between the Daka and the Gwai, occupied by an unwarlike and agricultural people akin to the Makalaka, and if any value can be placed on native testimony, these people were rich in cattle.

Attacked first by the Makololo and later on by the Matabele, these unfortunate people were killed in great numbers and gradually dispossessed of their lands, all their cattle being taken from them. Those that escaped death fled across the Zambesi, where their descendants are living to this day.

Now I have no doubt that long ago, before the country between the Gwai and the Daka rivers was settled up by natives, it had been a "fly"-infested country full of buffaloes. At any rate, as soon as the natives had been killed or driven out of it, buffaloes and all other kinds of game took possession of it, moving in no doubt from the countries both to the east and the west, and with them came a few tse-tse flies, which must soon have increased and multiplied in so favourable an environment.