Sable Antelope Subspecies
by Dr. Rolf Baldus
Sable Bull in the Kalahari
Discussing antelope sub species is a contentious matter. This statement applies also to the sable antelope, which occur in the large Miombo zones in sub-equatorial Africa. For hunting purposes, the classification is rather simple. All sable sub species are lumped together and are kept as one in the record books, with the exception of the Roosevelt Sable and the Royal Sable from Angola. An approach which seems to be to generalized if one takes a serious view of the hunters’ obligation towards the conservation of diversity of sub species and genetics.
The scientific literature shows five sable sub species. The sable populations of the Rift Valley in Cenral Tanzania are considered to be Kirk’s Sable (Hippotragus niger kirkii). The Common Sable (Hippotragus niger niger) occurs in Zambia, Botswana, Zimbabwe. Mozambique all the way into South Africa; some have been observed in the Caprivi (Nambia). In East Africa, starting at the Shimba Hill Game Reserve close to Mombasa in Kenya down the coast of Tanzania and into northern Mozambique, we find the Roosevelt’s Sable sub species (Hippotragus niger roosevelti), named after Theodore Roosevelt’s son Kermit, who accompanied the former US president on his epic safari to Africa in 1909. The Roosevelts also bagged sable antelopes during their safari and scientists in the United States later classified the hitherto unknown sable sub species from the Roosevelt trophies. This was quite an achievement, since there are only slight morphological differences like the horn length. A horn length of a fully mature Roosevelt Sable bull rarely exceeds 38 inch. Nevertheless, some sable hunted in the Selous GR brought in excess of 43 inch. An exact genetic classification would have been interesting in these cases. Soe people maintain that Roosevelt Sable are smaller in body and bulls do not have the jet black color, but rather a more brownish tone. I cannot confirm these observations, and I have seen many of these animals. The core concentration of Roosevelt Sable occurs within the Selous GR and along its eastern and southern buffer zones. The western border of its range has not been determined exactly yet, but I assume that it should cross the kilombero valley.
SCI classifies trophies from the Selous GR for some years correctly as roosevelti, and not as kirkii as in the past. I presented the scientific basis for this re-classification – also with a view to increase the economic value of these antelopes. Until now, SCI has not yet reached a decision to also accept the sable antelope of the Selous buffer zones as roosevelti. This concerns mainly the very large populations between the Selous GR and the Rovuma River. The Australian professor Colin Graves considers these populations and those in the bordering areas of Malawi and Eastern Zambia as another subspecies yet, Hippotragus niger anselli.
The Royal or Giant Sable (Hippotragus niger variani ) of Angola is the fifth and last recognized sub species.
These taxonomic subdivisions are based on exterior and anatomic differences, which are subject to habitat influences; they do not always permit a clear differentiation betweem populations. Today, scientists have the modern and exact DNA methologies as tools to determine genetic variations and to examine the validity of traditional sub species. In the case of the sable antelope, a team of scientists from Copenhague, Stellenbosch and Berlin – supported by many hunters – collected genetic material throughout the entire sable range. They used the results to craete a genetic map for this antelope. The map shows surprisingly large differences between three geographical groups, which coincide to a large extent with the sub species kirkii, niger and roosevelti. Although the visible differences between these three groups are relatively small, the genetic difference goes up to 18%. This is the greates difference found so far within one mammal genus. Just to put this statement into perspective: The genetic difference between two humans is measured in promille and the genetic difference between humans and chimpanzee has been calculated at 1.23%!
The classical sub species variani and anselli have been white spots on our genetic maps so far – now to be filled in!
As hunters we should look forward to the final completion of the genetic sable map – we will then have an excellent basis to support the conservation measures of the local authorities and the initiate scientifically based programs to mainyain the genetic diversity of the species. This will then hopefully also prevent the uncontrolled genetic mixing of sub species on certain South African game ranches.
Source: Prof. C. Pitra Institut für Zoo und Wildtierforschung, Berlin