Benfontein is situated 14 km south-east of Kimberley and consists of flat plains on the central South African plateau at an altitude of about 1 180 m a.s.l. A large calcrete pan (300 ha in size and c. 6 km in length) in the north-west fills with water during good rains, creating a fertile shallow wetland. Specialised salt-tolerant plant communities surround the pan and two prominent drainage lines flow into it from the east. Away from the pan, the ground levels off and red Kalahari sand occurs to the south-east. Underlain by calcareous tufa, the sand becomes deeper to the south. A few dolerite hills occur along the southern and south-western boundaries of the farm.
The vegetation is mostly semi-open savanna of the Savanna Biome, with the Nama Karoo Biome present around the pan. This IBA has a total of 12 habitat units within the three vegetation types: Highveld Salt Pans, Northern Upper Karoo and Kimberley Thornveld. The Highveld Salt Pans vegetation type is classified as Least Threatened (hardly protected and with 96.5% remaining intact). The Kimberley Thornveld is also listed as Least Threatened (poorly protected and 82.3% intact). In the Kimberley Thornveld, the vegetation is generally open camel thorn Vachellia (formerly Acacia) erioloba savanna in tall grass on deep red sands. The grass layer is complex and is dominated by love grasses Eragrostis species, silky awn grasses Stipagrostis species and stick grasses Aristida species. After good rains the flat country in the east becomes grassy, with red grass Themeda triandra, turpentine grass Cymbopogon plurinodis and love grasses dominating.
Most of the terrestrial habitats remain in a natural state, with some transformation due to farm buildings, a farm dam, old dumps, a large borrow pit and eroded areas.
This IBA supports small numbers of breeding White-backed Vulture Gyps africanus, Blue Crane Anthropoides paradiseus and Blue Korhaan Eupodotis caerulescens. The farm also holds several biome-restricted assemblage species and congregatory species, including Lesser Flamingo Phoeniconaias minor. Ludwig's Bustard Neotis ludwigii, Sickle-winged Chat Cercomela sinuata and occasionally Burchell's Sandgrouse Pterocles burchelli utilise the plains. The Kimberley Thornveld supports Kalahari Scrub Robin Erythropygia paena, Sociable Weaver Philetairus socius, Scaly-feathered Finch Sporopipes squamifrons, Violet-eared Waxbill Uraeginthus granatinus and Rufous-eared Warbler Malcorus pectoralis.
At least 242 species have been recorded during SABAP2 in the five pentads covering this IBA, but at the time of its assessment it had not been well atlased.
More than 16 years of CWAC data have revealed that there are high levels of fluctuation in waterbird numbers and species seasonally and annually. This is due to the ephemeral nature of Benfontein Pan, which only holds water for several months during above-average rainfall years. More than 1 700 waterbirds are present during years of high rainfall, and 65 waterbird species have been recorded on the pan. Of these, 44 species are regularly present. Dominant species in terms of numbers and duration of presence are Black-winged Stilt Himantopus himantopus, Cape Shoveler Anas smithii and South African Shelduck Tadorna cana (Herrmann et al. 2004). Species groups that occur in limited numbers, or for short periods, include primarily herons, grebes, flamingos, ibises and storks.
Globally threatened species are White-backed Vulture, Blue Crane, Lesser Flamingo, Blue Korhaan, Secretarybird Sagittarius serpentarius and Ludwig's Bustard. Regionally threatened birds are Tawny Eagle Aquila rapax and Greater Flamingo Phoenicopterus roseus. Biome-restricted birds are Sociable Weaver, Kalahari Scrub Robin, White-bellied Sunbird Cinnyris talatala and Burchell's Sandgrouse.
Benfontein is famous for its nocturnal specials such as aardwolf Proteles cristatus, black-footed cat Felis nigripes (Vulnerable), Cape fox Vulpes chama and aardvark Orycteropus afer. It also supports herds of springbok Antidorcas marsupialis and black wildebeest Connochaetes gnou, among other game. The farm is known for its flock of genetically pure Common Ostrich Struthio camelus, which apparently is not hybridised with East African ostriches.
There are presently few threats to this IBA as it is being well conserved. Climate change and predictions of bush thickening, with an increase in atmospheric CO2 levels, may be a significant threat in the near future. The invasive mesquite Prosopis glandulosa, currently present in the north-eastern section and spreading along the N8 on the eastern boundary, could become a significant threat if not controlled.
In order to conserve the White-backed Vulture, it is necessary to protect all its breeding colonies in this region. In 2001, when the only comprehensive survey was undertaken, six breeding colonies were located in the greater Kimberley area, with an estimated 240 breeding pairs and 650 individual birds (Murn et al. 2002). As these birds forage over wide areas, farmer extension is important to address threats such as food shortage, poisoning and drowning in farm reservoirs. The use of poisons in farming areas to combat mammalian predators still poses a threat to scavenging raptors, which are attracted to and consume the baited carcasses. Hundreds of vultures can be killed in a single poisoning incident.
Collisions with the power line transecting the eastern side of Benfontein are a threat to the White-backed Vultures and large terrestrial birds such as Blue Crane and Ludwig's Bustard.
Anglo American has recently bought De Beers Consolidated Mines and this change of ownership may lead to a change in land use or the sale of the property.
DBCM has owned Benfontein since 1891. Portions of the farm were used for cattle farming, but the land use changed to purely game farming more than a decade ago. The farm was declared a Natural Heritage Site in 1986.
There has been significant investment by research groups in studies on aardwolf, black-footed cat and Sociable Weaver that are at the forefront of scientific discovery. The study on the Sociable Weaver in particular has brought international attention to Benfontein. More than 30 volunteer field assistants from around the world have worked on this species since 2000. Considerable baseline information on its breeding biology has been built up over 21 years of research on the game farm, providing a firm base for rigorous studies that address cutting-edge questions about ecology and evolution. A number of these projects have also been directed at improving the conservation status of endangered species, such as the research conducted on the black-footed cat and the long-term monitoring of White-backed and Lappet-faced Vulture populations.
CWAC counts were discontinued when Mark Anderson, ornithologist at Northern Cape DENC, left in 2008. Incidental records of waterbirds and raptors are reported occasionally by researchers working in Benfontein.
This IBA forms part of the Diamond Route, a set of ten sites across South Africa that conserve biodiversity and provide education and sustainability opportunities through the De Beers Group of Companies, E Oppenheimer and Son and Ponahalo Investments. It is currently being managed as a nature reserve. DBCM is willing to enter into a Biodiversity Stewardship agreement to secure this IBA as a formally protected area under NEM:PAA.
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