The waters around Dyer Island are an important seasonal feeding ground for great white sharks. Researchers working through Dyer Island Conservation Trust have demonstrated a decrease in white shark sightings around the island since 2017. 

Of the two localities at which it is known to have occurred, the Brenton blue butterfly is now extinct at one (Nature’s Valley) and possibly extinct at the other (the Brenton Blue Butterfly Reserve near Knysna).

The tiny Critically Endangered Barrydale redfin, for example, is limited to just 40 km² in the Tradouw catchment where it is threatened by water abstraction, pollution and alien fish.

The rough moss frog occurs at a single locality on the southern slopes of the Klein Swartberg Mountain. The main threats to this species are invasive alien plants and too-frequent fires.

The geometric tortoise occurs only in the low-lying renosterveld shrublands of the Swartland, Upper Breede River Valley and Ceres Valley.

The Greater De Hoop Conservation Area is the stronghold of bontebok conservation. Together, De Hoop Nature Reserve and the adjacent Overberg Test Range support almost half of all bontebok on protected areas.

The Cape Vulture Colony at De Hoop Nature Reserve is one of the few populations of Cape Vulture (Gyps coprotheres) that is increasing in numbers. This is the only resident vulture within the Western Cape and is currently is listed as endangered. According to the IUCN conservation status report the global population is decreasing.