Dyer Island Nature Reserve

Country/territory: South Africa

IBA Criteria met: A1, A4i, A4ii, A4iii (1998)
For more information about IBA criteria please click here

Area: 20 ha

Protection status:

BirdLife South Africa
Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2014 high near favourable high
For more information about IBA monitoring please click here

Site description
Dyer Island is one of two low-lying islands situated 4.7 km south-east of Danger Point. The nearest harbour is at Kleinbaai/Franskraal, just south of Gansbaai. The coastline is rugged with some low rocky areas spreading inland. The island is flat and low-lying, with a pebbly surface. The vegetation consists primarily of Mesembryanthemaceae and non-native weeds (including conspicuous stands of Lavatera). In the south-eastern part of the island are several buildings that house the island staff, boats and stores.

Key biodiversity
See Box for key species. The discovery of Oceanodroma leucorhoa in several of the stone walls on the island in October 1995 was the first evidence of a procellariiform bird breeding in southern Africa. In November 1996 it was estimated that 8–9 pairs were breeding. In 1996, after an absence of some 25 years, Sterna dougallii, which breed regularly only at two other islands in southern Africa (Bird and St Croix islands in Algoa Bay; IBA ZA074), attempted to breed again at Dyer Island. The breeding attempt failed owing to suspected human disturbance. The population of Spheniscus demersus at Dyer Island is in rapid decline, and although the island supported some 72,500 birds in 1976, it is thought that the population may have fallen below 3,000 pairs in 1997.

Many other species breed on this island, including large numbers of Phalacrocorax capensis and small numbers of P. carbo, P. neglectus and P. coronatus. Several large colonies of Larus hartlaubii and Sterna bergii breed at the island. Sterna sandvicensis, S. hirundo, S. paradisaea and S. vittata form large, mixed tern roosts with the breeding S. bergii. Dyer Island is estimated to hold over 1% of the world population of Haematopus moquini.

Non-bird biodiversity: The waters around the island hold a large population of the shark Carcharodon carcharias (VU).

Recommended citation
BirdLife International (2019) Important Bird Areas factsheet: Dyer Island Nature Reserve. Downloaded from on 17/11/2019.