Sites - Important Bird and Biodiversity Areas (IBAs)
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Augrabies Falls National Park
South Africa, Northern Cape
20o 20.00' East 28o 35.00' South
582 - 914m
Year of IBA assessment
BirdLife South Africa
Summary The Augrabies Falls National Park is situated on the vast Bushmanland peneplain where it straddles the Orange River. The IBA falls within the Nama-Karoo Biome, with arid grasslands and open karroid thornveld present on the plains, and the rocky hills covered in a sparse vegetation type known as hardeveld.
Site description The Augrabies Falls National Park is situated on the vast Bushmanland peneplain where it straddles the Orange river, c.380 km inland of Alexander Bay. Between Kakamas and the Augrabies Falls, a distance of c.35 km, the river flows through a wide, flat, cultivated valley. From the 146-m-high falls at the park headquarters it meanders down a deep, narrow gorge for several kilometres before reaching the level surface of the surrounding plains once again. The rest of the park is flat with low relief, scattered with large rounded domes. Drainage channels are sandy, gravelly and dry and are mostly very shallow, or occasionally deeper with rocky sides and broad beds. The area is classed as an arid to semi-arid cold desert.The park’s vegetation comprises mainly Orange river Nama-Karoo, typically with trees and shrubs of Sarcostemma, Acacia, Rhus, Salix, Rhigozum, Boscia and Cadaba, and succulents (Aloe, Euphorbia) on the steep, rocky mountain-slopes. In the riverbeds, sandy deposits occasionally form islands that hold a tall open grassland. Upstream of the falls, the Orange river is a braided stream with much fine alluvial sand and silt forming complex islands, which hold gallery forest along the river arms, dominated by Ziziphus, Euclea, Maytenus, Rhus, Acacia and Tamarix, with Lycium and Diospyros in the shrub layer. Phragmites grows in patches along the river. In the gorges downstream of the waterfall Ficus grows sparsely on the rocks.
Key Biodiversity See Box and Table 3 for key species. A total of 195 species have been recorded in the park. Despite the low diversity, the park is important for many biome-restricted assemblage birds, as well as a host of other arid-zone species. The lowland plains are particularly good for large wide-ranging species such as Polemaetus bellicosus, Ardeotis kori, Neotis ludwigii and Eupodotis vigorsii. The plains also support Certhilauda albescens, Cercomela schlegelii, C. tractrac, C. sinuata and Malcorus pectoralis. Serinus alario occurs wherever there is seeding grass and water. The belts of riverine Acacia woodland hold Cercotrichas coryphaeus, C. paena, Phragmacia substriata, Sylvia layardi, Bradornis mariquensis, Sporopipes squamifrons and Agapornis roseicollis and provide food, shelter and breeding habitat for many other species. Large trees occasionally support the massive Philetairus socius nests with the associated Polihierax semitorquatus frequently in attendance. In very wet years nomadic Eremopterix australis move in and breed in large numbers, and are then absent until the next heavy rains, which can be decades apart. Onychognathus nabouroup, Apus bradfieldi and the secretive and localized Euryptila subcinnamomea occur in the river’s steep gorges and associated rocky kloofs.
Non-bird biodiversity: Among plants, the distinctive southern African endemic Aloe dichotoma is common within the park. The permanently flowing sections of the river support two important fish species, the Vaal-Orange river endemic Austroglanis sclateri (DD) and Barbus hospes (LR/nt), which is restricted to the Orange river below the Augrabies Falls. Among herptiles, this is the only protected area in the world supporting the endemic frog Phrynomerus annectens and the lizard Platysaurus broadleyi; the latter is restricted to the lower Orange river valley between Augrabies and Pella. The threatened mammal Diceros bicornis (CR) was reintroduced to the park in 1985.