ZA028
Platberg-Karoo Conservancy


Site description (2001 baseline):

Site location and context
The conservancy covers the entire districts of De Aar, Philipstown and Hanover in the south-eastern portion of the Northern Cape Province. Although the land in the IBA is primarily used for grazing and agriculture, it includes the suburban towns of De Aar, Philipstown, Petrusville and Hanover. This huge area lies in the plains of the central Great Karoo, forming part of the South African plateau. The conservancy consists primarily of open-plain country, locally interrupted by dolerite hills and small mountain ranges which rise 200–300 m above the surrounding plateau, which varies from 1,100–1,400 m in altitude.

Just north of De Aar, the ephemeral Brak river flows in an arc from south-east to north-west, eventually feeding into the Orange river basin. Several other ephemeral rivers occur in the IBA, including the Hondeblaf, Seekoei and Elandsfontein, which all have rocky beds with intermittent wide flood-plains that contribute to the Orange river catchment. Kriegerspoort Dam in the south and the Vanderkloof (formerly P. K. le Roux) Dam in the north-east form permanent water features in the area.

The vegetation that covers much of the plains and lower escarpment is dominated by shrubs, which seldom exceed 70 cm in height. The numerous kloofs are sparsely wooded and the hills and mountains are more grassy than the plains. During rainy periods, however, many patches of grass sprout on the rocky mountain slopes. The characteristic shrubs of the hills are species of Rhus. There are extensive sectors of dense thornveld dominated by Acacia, which forms belts of riverine woodland lining the mostly dry riverbeds.

Key biodiversity
See Box and Table 3 for key species. This area holds vitally important populations of two globally threatened species, several biome-restricted species and important populations of other arid-zone birds. The lowland karroid plains are particularly good for Neotis ludwigii, Ardeotis kori, large numbers of Eupodotis vigorsii, Certhilauda albescens, Cercomela schlegelii, C. tractrac, C. sinuata, Emberiza impetuani and the recently recognized Certhilauda subcoronata. In the grassier areas, Eupodotis caerulescens are common. Circus maurus are occasionally seen quartering the plains, where huge numbers of Grus paradisea regularly congregate. Aquila rapax and Polemaetus bellicosus breed on the power lines in the area. The belts of riverine Acacia woodland support Phragmacia substriata, Sylvia layardi and Parus afer. Onychognathus nabouroup and Anthus crenatus occur in rocky gorges and kloofs. Other arid-zone species occurring within the conservancy are Melierax canorus, Batis pririt, Stenostira scita and Serinus albogularis. Falco naumanni have roosts throughout the area, including large roosts in the towns of De Aar, Hanover and Philipstown; they are frequently seen foraging in the conservancy in summer. Some of the dams are important roosts—during summer 1996/97, more than 850 Grus paradisea were counted on a dam in the area.

Non-bird biodiversity: None known to BirdLife International.



Pressure/threats to key biodiversity
The only formally conserved reserve in the area is the small government-owned Rolfontein Nature Reserve (6,938 ha) in the north-east, which was declared in 1970. Small isolated reserves seldom fulfil the conservation requirements of large, wide-ranging, non-passerine birds. The only feasible long-term approach to conserving these species is to manage the agricultural landscape within which they live to suit their needs. The Platberg-Karoo Conservancy is an ideal example of how conservation goals can be achieved without sacrificing the farming potential of the land. Despite being an informal conservation area, the land-owners’ activities dramatically affect the important species that use this site, and their cooperation contributes enormously to establishing and maintaining vitally important and valuable conservation areas and populations of threatened species.

Threats in the area include overgrazing of the surrounding farmland, resulting in habitat degradation that potentially reduces populations of wide-ranging species, such as bustards and cranes. Strychnine and other poisons are used for problem-animal control in farming areas, which may affect scavenging raptor populations. Falco naumanni is also susceptible to poisoning through taking locusts in the midst of spraying operations. The effect that pesticides are having on this species is currently unknown.

Power lines in the district are a threat to large terrestrial birds such as cranes and bustards, which collide with them, and to raptors, which have been electrocuted while perching on them. Power lines can, however, also be beneficial to large raptors such as Polemaetus bellicosus which breed on them. The Northern Cape Nature Conservation Service (NCNCS) is undertaking a study of bird/power-line collisions in the Karoo and (with funding from Eskom) is attempting to devise mitigation measures.


Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Platberg-Karoo Conservancy (South Africa). Downloaded from https://datazone.birdlife.org/site/factsheet/platberg-karoo-conservancy-iba-south-africa on 23/11/2024.