Mr. Selous also points out that intermediate forms are found between the two subspecies of Elands, and that, in fact, there is a complete passage through a long series of variations from one form to the other.
That this is the case is shown clearly by Mr. Selous’s own observations. He writes (in the same work) as follows:—
“In April 1879 I shot some Elands in the Northern Kalahari, between Bamangwato and the Botletli River. None of these Elands showed any signs of stripes, but two of them had light grey patches on the insides of the fore-legs. About 150 miles farther north, however, nearly all the Elands that I shot were more or less striped, though in most cases the stripes were so faint that they only became apparent on a close inspection. Travelling northwards towards the Chobi River, I found that although Elands were still to be met with, on which no stripes could be detected, most of them were more or less plainly striped, the patches on the insides of the fore-legs becoming gradually darker at the same time. North of the Chobi, and between that river and the Zambesi, the Elands, taken as a whole, become well striped, and the dark markings on the insides of the fore-legs more and more conspicuous, many individuals being as richly marked as the real Taurotragus oryx livingstonii, which was first observed by Dr. Livingstone at Sesheke, immediately north of the Central Zambesi. Thus, speaking from my own experience, I should say that all the Elands found in South Africa at the present day south of the 23rd parallel of latitude are grey Elands (Taurotragus oryx typicus), but that north of that parallel of latitude a tendency to show white stripes on each side of the body, and dark patches on the insides of the fore-legs, together with a dark median line down the centre of the back, from the withers to the tail, commences. I would say further that this tendency is at first confined to certain individuals, but becomes more general, and the white stripes and dark markings gradually more intensified in individuals, as one travels north and north-east, until north of the Zambesi and in Mashunaland, and all over South-eastern Africa, all the Elands are striped without exception, and all of them show black patches on the insides of the fore-legs and a dark mark down the centre of the back, and often a white arrow-shaped mark across the nose, as in the Koodoo and Bushbuck.”
Mr. Bryden and other well-known authorities on the game-animals of South Africa entirely confirm Mr. Selous’s observations.
Under these circumstances it seems quite impossible to treat Livingstone’s Eland as a distinct species, but, as will be seen by our list of synonyms, we have placed it under a different heading, and have assigned most of the references to Elands north of the Zambesi to Taurotragus oryx livingstonii.
We will now, starting from the Zambesi, endeavour to trace the Eland into the most northern part of its range.
Fig. 116.
Skull and horns of Livingstone’s Eland, ♂.
(P.Z.S. 1895, p. 690.)