// // // //
SONGS
ADVERTISE
Advertise with us:
R10 000 pm VAT excl.

Wildlife matters

BACK
HOME » Wildlife » Wildlife matters

Bontebok or blesbok?

23 May 2013

As a result of its historical, geographic distribution it is not surprising that the bontebok Damaliscus pygargus pygargus was described scientifically before the blesbok became known to science. The primary habitat of the bontebok was fynbos interspersed with grassland along the southern Cape coast while the blesbok preferred the inland sour grasslands. Although there are isolated mentions in the Eastern Cape to blesbok occurring south of the Winterberg Mountains, this was most likely temporary excursions in times of good rainfall. In the Western Cape the bontebok was historically limited to the region between Riversdale and just west of Caledon which were 60 to 200 m above sea level and received from 300 to 700 mm of rain per year. The closest blesbok population occurred some 250 km eastwards in the interior near Grahamstown. Both the blesbok and bontebok are primarily short grass feeders in regions where water is readily available. There is no English name for either of these two types of antelope and they are simply known by their Afrikaans names which have a Dutch origin. These names refer to their external appearance.

The bontebok was first described scientifically as Antilope dorcas by Pallas in 1766 on the basis of a specimen that was collected along the Kafferskuil River near Riversdale. In 1767 Pallas realized that he had misnamed the bontebok and he changed its scientific name to Antilope pygargus. However, because Antilope is restricted to India, the generic name Damaliscus was coined in 1894 by Sclater and Thomas for a series of related wildlife. The name Damaliscus was derived from the common name damalisk for Hunter’s hartebeest which was once known as Damaliscus hunteri but is now known as Beatragus hunteri. The bontebok was once regarded as a separate species Damaliscus pygargus. The name pygargus is of Latin origin and indicates an antelope with a white buttock. This name was also used by older writers when they referred to the springbok with its white dorsal crest. The blesbok was only named scientifically more than a century later as another species Damaliscus phillipsi by Harper in 1939 based on a specimen form the Free State. Later it was found that the bontebok and blesbok were in reality two subspecies of Damaliscus pygargus. They both have a common ancestor Damaliscus niro which still lived some 12 000 years ago at Sterkfontein in the Gauteng province.

There are clear morphological differences between a blesbok and a bontebok although they appear to be similar at first glance. One obvious difference is that a blesbok has a fawn to pale brown buttock with white sometimes on top of the tail base, while the buttock of a bontebok is white which circles the tail base and the tail base is white above. The blesbok has a general fawn to pale brown colour while the bontebok is darker brown with a purple tint on the upper parts. In most animals the bontebok does not have a brown band over the white forehead above the eyes although this band is present in 19 per cent of the individuals examined. The brown band is present in most of the blesbok individuals although it may be absent in some of them. The hind legs of a bontebok are white from the knees down but they are dark brown in a blesbok. The upper parts of the horn rings of a bontebok are black but they are straw-coloured in a blesbok.

Because these two types of wildlife are only subspecies of the same species they have produced fertile hybrids because they eat the same type of food and have been moved into the same geographic and habitat areas. Doing so has genetically polluted many populations of these two subspecies. Pure bontebok are rarer and more in demand on live wildlife auctions than pure blesbok. In 2012 the mean price on these auctions for a blesbok was R1262 as opposed to one of R4000 for a bontebok. However, the price for a pure bontebok has increased sharply in 2013.

Recent DNA studies have shown that pure bontebok currently occur in the Bontebok National Park and in some localities in the Free State province. Pure blesbok occur mainly in the Free State, Northern Cape, Gauteng and Mpumalanga provinces. Genetically there are 32 alleles that are typical of a pure blesbok and 11 that are typical of a pure bontebok. Alleles are alternative forms of a gene that developed through mutation but occur on the same locus on a chromosome. These variations indicate significant genetic differences between these two subspecies. Because they can hybridize to produce fertile offspring they should never be kept together. Artificial hybridization of wildlife such as the blesbok and bontebok is detrimental for each type and for the biodiversity of our wildlife heritage. The bontebok is a rare antelope whose survival is threatened because it occurs at low population levels with a low gene pool and consequently has a low genetic diversity. This reduced genetic diversity was probably caused by intense hunting pressure in the 1700s which greatly reduced the original population. A national bontebok breeders association will in future manage the surviving population.

The blesbok is generally being used to buffer rare wildlife against predation in areas with large predators because it is cheap and easy prey. However, the bontebok is too rare to do so. Hybrids of the bontebok and blesbok have no value for trophy hunting or tourism and should be removed from all populations. The blesbok does well in bushveld areas but where sweetveld occurs they can reduce the veld condition over time by patch-selective grazing. It must therefore be managed with circumspection when it does not occur in its normal tufted, sour grassland habitat. Because it occurs in large herds the meat of the blesbok is currently the second highest source of African wildlife meat that is being exported from South Africa to western Europe. The meat of the bontebok is not being exported because it is a rare and protected antelope.

 

References:

Cloete, P C 2012. Tendense van lewendewild-verkope 2012. Game & Hunt 19(2): 51 - 55.

Oberem, P. 2011. Co-operation, value-adding ‘key venison production’. Game & Hunt 17(6): 69 - 71.

Skead, C J 2007. Historical incidence of the larger land mammals in the broader Eastern Cape, second edition. Port Elizabeth: Nelson Mandela Metropolitan University.

Skead, C J 2011. Historical incidence of the larger land mammals in the broader Northern and Western Cape, second edition. Port Elizabeth: Nelson Mandela Metropolitan University.

Skinner J D & C T Chimimba, (Eds) 2005. The mammals of the southern African subregion, third edition. Cambridge: Cambridge University Press, pp 653 - 658.

Van Wyk, A M, A Kotzé, E Randi & D L Dalton 2013. A hybrid dilemma: a molecular investigation of South African bontebok (Damaliscus pygargus pygargus) and blesbok (Damaliscus pygargus phillipsi). Conservation Genetics DOI 10.1007/s10592-013-0448-0.

By: Prof J du P Bothma

 

Click here to buy music, videos and images
SONGS
ADVERTISE
Advertise with us:
R10 000 pm VAT excl.