Habitat and Ecology
IUCN Red List Assessment
Red List Category
Red List Criteria
While the total number of mature individuals (i.e., those aged 7 years+) now exceeds 1,000 individuals this threshold number was probably only reached around early 2010 (based on extrapolations, AfRSG and SADC RMG population estimates and an empirically derived adult % of 55.8% for 2005 and 2006). To qualify to be reclassified as Near Threatened (NT) requires there to have been more than 1,000 adults for at least five years and this is currently not the case and so the rating remains Vulnerable (VU). Numbers of the subspecies are continuing to increase, numbering 1,920 individuals by the end of 2010. Despite the facts that there are fewer D. b. bicornis than D. b. minor, in fewer subpopulations, and in fewer countries, D. b. bicornis still qualifies to be listed as VU because numbers of this subspecies have (in contrast to D. b. minor) increased over the last three generations. The significant increase in commercial poaching in neighbouring South Africa and Zimbabwe and increasing black market horn price and hence increasing illegal demand poses an ongoing threat to this subspecies.
- 2003Vulnerable(IUCN 2003)
Diceros bicornis bicornis
The southern black rhinoceros or Cape rhinoceros (Diceros bicornis bicornis) is an extinct subspecies of the black rhinoceros that was once abundant in South Africa from the Cape Province to Transvaal, southern Namibia, and possibly also Lesotho and southern Botswana. It was brought to extinction by excessive hunting and habitat destruction around 1850.
It is unknown from where the original specimen (the holotype), on which Carolus Linnaeus based "Rhinoceros" bicornis in 1758, was collected. It was even proposed that it was indeed the skull of an Indian rhino (Rhinoceros unicornis) with a faked second horn, as Linnaeus erroneously noted India as occurrence. This was fixed formally in 1911, when O. Thomas declared the Cape of Good Hope as type locality of D. bicornis. Therefore this population formed the base of the nominal subspecies of the black rhinoceros. Later this subspecies became frequently mistaken for the south-western black rhinoceros, but the latter has to be considered a separate subspecies (D. bicornis occidentalis).
D. bicornis bicornis was the largest of all black rhino subspecies. While the differentiation of subspecies is mostly based on skull and body proportions, as well as details of the dentition, the external appearance of the southern subspecies is not exactly known because no photos exist. The skull was the largest of any known subspecies and proportionally large compared to the body. The limbs were short but slender and the skin folds were probably only weakly pronounced.
This subspecies was restricted to well-vegetated regions in contrast to others which are well adaptated to desertic conditions.
As the IUCN considers the living northern Namibian black rhino populations (D. bicornis occidentalis) to belong to D. bicornis bicornis, the latter is listed as "vulnerable" instead of "extinct". This synonymy, based upon du Toit (1987) was, however, considered erroneous by Groves and Grubb (2011).
- Hillman-Smith, A.K.K. & Groves, C.P. (1994). "Diceros bicornis" (PDF). Mammalian Species (American Society of Mammalogists) 455: 1–8. doi:10.2307/3504292. JSTOR 3504292.
- Rookmaaker, L.C. & Groves, C.P. (1978). "The extinct Cape Rhinoceros, Diceros bicornis bicornis (Linnaeus, 1758)" (PDF). Säugetierkundliche Mitteilungen 26 (2): 117–126.
- Rookmaaker, L.C. (2005). "Review of the European perception of the African Rhinoceros" (PDF). Journal of Zoology 265: 365–376. doi:10.1017/s0952836905006436.
- Thomas, O. (1911). "The mammals of the tenth edition of Linnaeus: an attempt to fix the types of the genera and the exact bases and localities of the species". Proceedings of the Zoological Society of London 1: 120–158.
- Groves, C.; Grubb, P. (2011). Ungulate Taxonomy. Baltimore: The Johns Hopkins University Press. p. 317. ISBN 978-1-4214-0093-8. Retrieved October 7, 2012.
- Emslie, R. (2011). "Diceros bicornis ssp. bicornis". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. Retrieved 18 January 2012.
- du Toit, R. (1987). "The existing basis for subspecies classification of black and white rhino" (PDF). Pachyderm 9: 3–5.
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