Located 5 km west of Port Edward, Umtamvuna Nature Reserve occupies the eastern side of a steep gorge on the Umtamvuna River at an altitude that ranges from sea level to 447 m a.s.l. The river gorge meanders through the reserve for 25 km before it enters the Indian Ocean 2 km beyond the reserve boundary. Many precipitous side streams join the river within the reserve. The river is flanked by evergreen forests that are overtopped by up to 240 m of often sheer cliffs. These consist of Pondoland Sandstone, with small exposures of granite and dolerite in the valley bottom. Above the cliffs, on either side, are gently undulating sandy, grassy plains on which little-eroded rocky outcrops are scattered. There are many seepages and small vleis. The climate is warm-temperate, and the area receives an average rainfall of 1 256 mm p.a., falling mostly in summer.
The vegetation is Pondoland–Ugu Sandstone Coastal Sourveld, as well as Scarp Forest that boasts more than 330 woody species. It has typical coastal elements, together with species usually associated with the mistbelt, but many of the dominants are near-endemics. The grassland is also exceptionally diverse and only a third of its species are grasses; the remainder are sedges and forbs.
Black Stork Ciconia nigra breeds in the extensive series of cliffs in the Umtamvuna Gorge. The grasslands covering the rolling hills above the gorge hold threatened species such as Southern Ground-Hornbill Bucorvus leadbeateri, African Grass Owl Tyto capensis and Black Harrier Circus maurus. The backwaters of the river are the home of African Finfoot Podica senegalensis. The well-developed Scarp Forest supports a small population of Spotted Ground Thrush Zoothera guttata in winter. Other forest species include Knysna Turaco Tauraco corythaix, Knysna Woodpecker Campethera notata, Chorister Robin-Chat Cossypha dichroa, Brown Scrub Robin Erythropygia signata, Black-bellied Starling Notopholia corrusca, Grey Sunbird Cyanomitra veroxii and Forest Canary Crithagra scotops. The scrub and bush at the forest edge hold Natal Spurfowl Pternistis natalensis and Gorgeous Bush-Shrike Chlorophoneus viridis.
Spotted Ground Thrush and Knysna Woodpecker are globally threatened species. Regionally threatened species are African Finfoot, African Grass Owl, Lanner Falcon Falco biarmicus, Half-collared Kingfisher Alcedo semitorquata and African Broadbill Smithornis capensis. Biome-restricted species that may be encountered are Knysna Turaco, Knysna Woodpecker, Chorister Robin-Chat, Brown Scrub Robin, Black-bellied Starling and Gurney's Sugarbird Promerops gurneyi.
Oribi Ourebia ourebi is present in the grasslands and blue duiker Philantomba monticola occurs in the forest. Transkei dwarf chameleon Bradypodion caffrum, a Pondoland coastal plateau endemic, is present, as are the butterflies Pondoland charaxes Charaxes pondoensis and Amakoza rocksitter Durbania amakosa albescens.
The forest is the only or the principal home of a host of rare trees. Examples are Catha abbottii, Ochna chilversii, Colubrina nicholsonii, Manilkara nicholsonii, Pseudosalacia streyi, Eugenia umtamvunensis, E. verdoorniae, Dahlgrenodendron natalensis, Syzygium pondoense, Indigofera braamtonyi, Maytenus abbottii and M. bachmannii. Rare grassland plants include Searsia (formerly Rhus) pondoensis, Leucadendron spissifolium, Encephalartos laevifolius, Raspalia trigyna, Podalyria velutina, Psoralea abbottii, Phyllanthus arvensis, Anisodontea scabrosa, Erica abbottii, Brachystelma australe, Selago peduncularis and Helichrysum diffusum. Rock outcrops bear Anthospermum streyi, Apodytes abbottii, Craterostigma nanum, Canthium suberosum and C. vanwykii.
Umtamvuna was owned from 1939 onwards by the Forestry Department, with the original intention of planting timber. However, the land was unsuitable for this purpose and was never developed. Instead, it was given to the KwaZulu-Natal Nature Conservation Service (currently EKZNW) to be proclaimed a nature reserve in 1971. The reserve was enlarged in 1983. During the 1980s two threats loomed, both of which seem to have receded. The first was a proposal to dam the river downstream of the reserve, to boost the water supply for Port Edward. The dammed water would have backed up into the reserve, inundating the adjacent riverine vegetation. The second was a plan to mine bauxite in the catchment upstream of the reserve. There can be little doubt that severe contamination of the river would have resulted.
A Cape Vulture colony used to occur and supported up to 50 breeding pairs, but for reasons that are not immediately apparent the colony has been abandoned.
Umtamvuna is a centre of palaeo-botanical endemism. The sandstone substrate is ancient and appears to have acted as a barrier to plant migration, as well as having trapped the flora already resident. It is, in terms of plant species per unit area, one of the most diverse places in South Africa and carries the finest remaining example of Pondoland Sandstone flora. Some of the plants are extremely rare and localised. Raspalia trigyna, for example, was at one time thought to be represented by only a single plant. This was killed in an accidental fire. Another plant has been discovered in the reserve and attempts have been made to re-introduce the species using cuttings from plants discovered in the Transkei.
Piper S. 1985. Observations on the Cape Vulture at Umtamvuna, Natal. Bokmakerie 37: 35–37.
Piper SE. 1994. Mathematical demography of the Cape Vulture. PhD thesis, University of Cape Town, South Africa.