Besides the areas discussed so far, small relic populations are known to occur in the Mount Darwin and Chipinga districts. Fothergill's survey of the Mount Darwin district indicated a population of 31 animals, in three groups of 6, 10 and 15 animals, in small localities on tribal trust land. (Two of these were recently found dead.) Roth's estimate for this district was 22.
numbers and distribution of black rhino in Rhodesia
A small pocket of about eight animals was known to occur in the Chipinga district. When Roth assessed this population there were 8 - 12 animals, but a recent capture operation in the area recovered only one animal, and that only after a very intensive search.
Rhinoceros have the maximum legal protection having recently been placed on the royal game schedule, but this may be insufficient without intensive research and applied management.
Roth and Child (1968) investigated the density and structure of the rhinoceros population marooned on the islands in Lake Kariba during the rescue operations between 1959 and 1963. The overall mean density in the studied area between the Sanyati and Mwenda rivers was one rhinoceros per 4.5 - 5.3 square miles, and local abundance was found to be inversely related to the degree of human settlement. Roth (1967) considered that the population studied was relatively undisturbed and regarded these density figures 'as applicable in general to other parts of the valley'. In our opinion, however, they are high. The flooding of the low-lying areas greatly reduced the areas of previously occupied habitat. Fothergill, who was in charge of rescue operations, found that rhinoceros were very poor swimmers and once out of their depth would return to land. Rhinoceros on the islands were thus unable to disperse, and, in view of the artificial conditions prevailing during the study period, the density figures would appear to be too high. Even if they are accurate it is doubtful whether they can be applied with any assurance to other areas of the mid-Zambezi valley. The area of the valley between Kariba and the Mozambique border was widely settled by the Makorekore people up to 1958. Although primarily agriculturists, these people hunted and snared game, using primitive weapons, and over the years they must have had a profound effect on the rhinoceros populations. We think that Roth's density figures for areas moderately to sparsely settled by the Tonga people do not necessarily apply to this area east of Kariba, and that, because of the long term settlement and associated disturbance, rhinoceros densities are considerably lower there and the distribution more patchy.
Fothergill, who was in charge of rescue operations, found that rhinoceros were very poor swimmers and once out of their depth would return to land.
