This IBA was extended in 2014 to include the previous Graskop Grasslands and Mac-Mac Escarpment & Forests IBAs.
The Blyde River Canyon is located c. 8 km north of Graskop and 18 km south-west of Hoedspruit. It stretches for nearly 20 km as it cuts a spectacular path through the granite of the South African escarpment, and in places reaches a depth of 700 m. The IBA includes the Blyde River Canyon Nature Reserve, the Swadini and Manoutsa sections of the Mpumalanga Drakensberg escarpment that fall outside the reserve, and a number of State forests. At the confluence of the Blyde and Ohrigstad rivers, in the northern section of the reserve, an impoundment forms the Blydepoort Dam. The spectacular gorge is flanked by some remarkable peaks, including Marakalala, the Three Rondawels (1 749 m a.s.l.), Magale (1 688 m a.s.l.), the Three Sisters (1 704 m a.s.l.), Scotland Hill (1 736 m a.s.l.), Devil's Window (1 771 m a.s.l.), the Peak (1 832 m a.s.l.) and God's Window (1 730 m a.s.l.). Several rivers, including the Blyde, Origstad and Treur, cut impressive gorges through the rock. Large patches of high-altitude Afro-temperate forest are found in valleys, along scarp basins and in moist areas throughout the Blyde River Canyon. They contain distinct strata of emergent canopy trees and shrub layers, and trees can reach heights of up to 30–40 m. Montane grassland dominates on open exposed slopes with shallow lithosol substrates where frost and fire are regular.
The grassland near Graskop lies within South Africa's mist-belt region and consists of two patches of fragmented, gently undulating sour grassland, which are separated from one another by a plantation. The first grassland patch, Graskop 564 KT, lies immediately west of Graskop town and is infiltrated by narrow drainage lines. The grassland in this area is severely fragmented, with plantations surrounding each piece. The first piece of primary grassland occurs at Townlands West. To the south, a narrow tongue of grassland known as Malidyke stretches for 3 km from the western section of Townlands West. The third piece of grassland, the hilly Stanley Bush Kop, lies farther west, south of Pilgrim's Rest. The grasslands at Graskop 564 KT are separated from those at Lisbon Ridge by the farm Driekop 546, which is entirely afforested with pines. Lisbon Ridge lies c. 8 km due north of Graskop town.
The Mac-Mac area is located between Graskop and Sabie. Large parts of it are under pine plantations, but the rest comprises superb escarpment cliffs with associated grassland and indigenous forest. There are numerous cliffs that have been carved by the Mac-Mac River in the north and the Sabie River in the south. This area holds the famous Mac-Mac Falls in the north and Bridal Veil and Lone Creek falls in the south.
This is the only site in South Africa that supports breeding Taita Falcon Falco fasciinucha. More than 660 pairs of Cape Vulture Gyps coprotheres occur on the cliffs at Manoutsa. The gorges also hold breeding Black Stork Ciconia nigra, Peregrine Falcon Falco peregrinus and Cape Eagle-Owl Bubo capensis.
Pel's Fishing Owl Scotopelia peli, White-backed Night Heron Gorsachius leuconotus, Half-collared Kingfisher Alcedo semitorquata and African Finfoot Podica senegalensis may be found along the quiet backwaters of the river. The surrounding grassland supports Black-rumped Buttonquail Turnix nanus, Striped Flufftail Sarothrura affinis, Buff-streaked Chat Campicoloides bifasciata, Denham's Bustard Neotis denhami, Blue Crane Anthropoides paradiseus, African Grass Owl Tyto capensis and Southern Bald Ibis Geronticus calvus. The proteoid hill slopes hold Gurney's Sugarbird Promerops gurneyi.
In the forest and at forest edges occur Crowned Eagle Stephanoaetus coronatus, Forest Buzzard Buteo trizonatus, Buff-spotted Flufftail Sarothrura elegans, Lemon Dove Aplopelia larvata, Orange Ground Thrush Zoothera gurneyi, Bush Blackcap Lioptilus nigricapillus, Knysna Turaco Tauraco corythaix, Barratt's Warbler Bradypterus barratti, Olive Bush-Shrike Chlorophoneus olivaceus, Chorister Robin-Chat Cossypha dichroa, Brown Scrub Robin Erythropygia signata, Swee Waxbill Coccopygia melanotis and Forest Canary Crithagra scotops. Bat Hawk Macheiramphus alcinus has been recorded in dense riverine areas. Martial Eagle Polemaetus bellicosus is frequently seen soaring over the bushveld-dominated parts of the reserve, which also hold White-throated Robin-Chat Cossypha humeralis and Gorgeous Bush-Shrike Chlorophoneus viridis.
The Graskop grasslands support a number of breeding Blue Swallows Hirundo atrocaerulea and are one of the few remaining sites in South Africa that host this species.
Globally threatened species are Southern Bald Ibis, Cape Vulture (800–1 000 individuals, 420–530 pairs), Taita Falcon (8–20 individuals, 4–9 pairs), Blue Swallow, Bush Blackcap, Crowned Eagle, Secretarybird Sagittarius serpentarius and Denham's Bustard. Regionally threatened species are Lanner Falcon Falco biarmicus, Half-collared Kingfisher, Orange Ground Thrush, White-backed Night Heron, Black-rumped Buttonquail, Striped Flufftail, African Finfoot and Black Stork.
Restricted-range and biome-restricted species include the common Knysna Turaco, Grey Cuckooshrike Coracina caesia, Kurrichane Thrush Turdus libonyanus, Buff-streaked Chat, Chorister Robin-Chat, Barratt's Warbler, Yellow-throated Woodland Warbler Phylloscopus ruficapilla, Olive Bush-Shrike, Swee Waxbill and Forest Canary. Uncommon species are Forest Buzzard, White-starred Robin Pogonocichla stellata, Gurney's Sugarbird, Southern Bald Ibis, Striped Flufftail, Orange Ground Thrush and Brown Scrub Robin.
The development of additional recreational facilities in the IBA should be carefully evaluated and implemented to ensure that they do not impact negatively on the IBA’s important habitats. Areas under Eucalyptus and Pinus plantations are not expanding, but the amount of water used by these trees remains a concern. Other invasive alien plants include Australian blackwood Acacia melanoxylon, black wattle A. mearnsii, bugweed Solanum mauritianum, American bramble Rubus cuneifolius and Japanese privet Ligustrum japonicum.
Some of the rivers flowing through the IBA are under threat of pollution from mines, towns and agricultural areas. Uncontrolled fires occur regularly, impacting negatively on the quality of the grasslands and other habitats in the IBA. There are numerous small rural villages in and around the IBA that would pose a long-term threat if they were to expand significantly. Cattle grazing illegally in the Stanleybush Kop area pose a major threat to the Blue Swallows breeding there.
MTPA owns the Blyde River Canyon and Mac-Mac nature reserve, as well as the Graskop grasslands, which it acquired from DWAF in 1996. DWAF owns Mariepskop, Salique, Hebron, Welgevonden and Onverwacht State forests. Detailed management plans exist for all the properties and include activities such as removing exotic vegetation, creating fire-breaks and implementing grassland rejuvenation.
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