Following World Rhino day on 22nd September, I thought I would share a very interesting chat on the white rhino that myself and Dr Findlay were lucky to be in the audience for at the recent Southern African Wildlife Management Association conference. The presentation was by Professor Yoshan Moodley who works in genetics at the University of Venda.
The white rhino (Ceratotherium simum) has historically been considered as two subspecies – the Northern White Rhino and the Southern White Rhino. The current dispersion of these animals is quite different to the considered historical range. Despite both undergoing changes, the histories of each and the pressures faced follow different stories. The southern white rhino population has recovered to be the world’s most numerous rhino, but had seen a great decline in its number to its all time low at the turn of the 19th Century. The northern white rhino remained common through the majority of the 20th Century, before experiencing a rapid decline from the 1970’s onwards to the two remaining today.
The study used genetic sampling to review the demographic history of the two subspecies. Using museum samples the study was able to form a considerable data set to conclude prehistoric interglacial population declines in both, as well as, inevitably, declines by human impact – on the northern by Bantu migrations, and the southern through colonial expansion. Most significantly, there was detection of secondary contact between the two as recently as the last glacial maximum, approximately 21,500 years ago. Where other species have experienced issues when left with a low genetic diversity in their population, for example the Cheetah’s kinked tail amongst other issues; these results suggest that the white rhino has not experienced such drastic impacts, despite having been subjected to regular fragmentation of their population, and as a result low genetic diversity. In fact it seems they may have then recovered through this secondary contact during glacial periods.
The results therefore suggest there may be the potential for a hybrid rescue strategy to sustain the northern white rhino.
The question at the end of this presentation, posed by Professor Moodley, was should we intervene in this way? Can humans get this breeding right? Or if they are so similar can we just move some of the more numerous southern white rhinos up to where the northern white rhino used to exist?
Nonetheless, an interesting and, potentially, extremely positive outcome for efforts to conserve the white rhino.
Let us know what you think should happen.