The habitat diversity account for an equally diverse number of mammals in the area. Some species, however, were lost due to the agriculture and resultant loss of habitat. Today many of these species are making a comeback through the re-introduction policies. Species being re-introduced include eland, red hartbeest, buffalo and Cape mountain zebra.

The most ubiquitous species must certainly be Chacma baboons. They seem to have been just as plentiful, if not more so, in earlier times. The Dutch word for baboon, "baviaan" gave the area its name. The animals were so plentiful that the establishment of a small baboon hide-processing factory was initiated in the 1920's within the Baviaanskloof. You must please help authorities by refraining from feeding the baboons and monkeys as this will eventually lead to problem animals having to be shot.

The low-lying valley slopes and bottoms are a haven for bush loving species like kudu, bush buck, common duiker and Cape grysbok. Buffalo tend to lie up in thick ravine bush during the day and move up into the densely vegetated slopes at night to feed. The high-lying grassy plateaus and fynbos covered mountains are home to the red hartbeest, Cape mountain zebra, mountain reed buck, grey rhebuck and klipspringer. The eland are the great wanderers, moving over vast distances and utilizing a variety of habitats.

Caracal and leopard are the main predators in the area, Although caracal may occasionally be seen, the sighting of a leopard is still a very rare and noteworthy event (recent evidence suggests that their numbers are increasing). Cape clawless otter, bushpig, aardwolf, aardvark and a host of other smaller mammals are still reasonably common despite being seldom seen.

Four tortoise species occur within the area, of these most likely to be seen are the marsh terrapin and the large leopard tortoise. The tent tortoise, a Cape endemic, is occasionally seen in the drier western and north-western areas while the angulate tortoise is a common resident of the southern part of the Baviaans.

Although the majority of the 24 snake species found in the area have a wide distribution range, 4 of these are South African endemics. The snakes most likely to be seen are Cape cobra, puffadder, boomslang, rhombic skaapsteker, Karoo and montane grass snakes and the brown water snake. The Cape cobra and puff adder, are generally regarded as the two most dangerous.

The lizard fauna of the wilderness area is remarkable. Of the 28 species present, 2 newly discovered species, a dwarf chameleon Bradypodion sp. and a flat gecko Afroedura sp. are endemic to the area. A further 7 species are Cape endemics and 7 others are South African endemics!. Most of these occur in the mountainous parts. In summer the Nile monitor is commonly seen near water. The ubiquitous Southern rock agama can be found almost wherever there are rocks and sunshine.

The rivers flowing through the area support a diverse indigenous fish fauna - 15 species are known to occur here, of which 3 are endemics to the rivers of the Cape.