A review of black rhino systematics proposed in Ungulate Taxonomy by Groves and Grubb (2011) and its implication for rhino conservation.

Pachyderm 50: 72-76.

Auszug:

A new and comprehensive taxonomy of all groups of ungulates was recently published by Colin Groves and Peter Grubb (1935-2006). After an insightful introduction covering methods and species concepts, an arrangement is presented of all recent (and a few extinct) ungulate groups. In the Rhinocerotidae, the list includes six species: Rhinoceros unicornis (no subspecies), R. sondaicus (3 subspecies), Dicerorhinus sumatrensis (3 subspecies), Diceros bicornis (8 subspecies), Ceratotherium simum (no subspecies) and C. cottoni (no subspecies). This treatment is very similar to that in previous work by Groves, except for the recognition of the Nile rhinoceros (C. cottoni) as a separate species (Groves et al., 2010) and for the addition of an eighth subspecies of D. bicornis (D.b.occidentalis, separated from D.b.minor).
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It is certainly understandable that to most field workers the conclusions proposed by Groves (1967) resembled a bombshell. Where there were to all intents and purposes no subspecies before, now suddenly there were seven. Not only that, but a cursory look at his paper reveals a rather intricate discussion of clines in Kenya and Tanzania, illustrated by a bewildering array of dots and lines on a map of the region. The budding conservation society in East Africa all at once had to come to grips with the possibility that they would have to cope with a set of at least three subspecies with all kinds of intergrades. And of course, even the best observers of rhinos in the field would have felt unable to differentiate the various subspecies when observing the animals in the field. Rhinos differ in size of skulls and skeletons, but there was little to distinguish one from another in the bush.
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It is high time that the discrepancy in the understanding of subspecific differentiation in the black rhino is resolved (Rookmaaker, 1995, 2005). It should not be allowed to continue any longer. Groves and Grubb (2011) have presented a classification of the recent rhinos, which is certainly the best achievable reflection of their diversity. It is based on sound theoretical premises, correct application of modern methodologies, accurate adherence to the rules of nomenclature, a wealth of morphometric data from the majority of available specimens, a wide-ranging knowledge of the literature and life-long interests in the biology of the rhinoceros. We must now deal with their results and cherish the great biodiversity in nature...

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