Most alien looking place on Earth

14 April 2014 | Fact sheet

Socotra Archipelago World Heritage Site, Yemen

Background
A world heritage site since 2008, Socotra (Arabic: سُقُطْرَى‎ Suquṭra), also spelled Soqotra in Yemen, is a small archipelago of four islands in the Indian Ocean. The largest island, Socotra and three smaller islands of Abd al Kuri, Samhah and Darsa as well as small rock outcrops like Ka'l Fir'awn and Sābūnīyah. Some of these are uninhabitable by humans but essential for seabirds. Socotra is very isolated. A third of its plant life is found nowhere else on the planet. It has been described as "the most alien-looking place on Earth".

View image of the site

Size and Location
The archipelago lies some 240 kilometres east of the Horn of Africa and 380 kilometres south of the Arabian Peninsula. The largest island measures 132 kilometres (82 mi) in length and 49.7 kilometres (30.9 mi) in width.

Fauna and Flora
The main island has three geographical terrains: narrow coastal plains, limestone plateaus permeated with karstic caves, and the Haghier Mountains, rising to 1,503 metres.

The long geological isolation of the Socotra archipelago and its fierce heat and drought have combined to create a unique and spectacular endemic flora. The entire flora of the Socotra archipelago has been assessed for the IUCN Red List, with 3 Critically Endangered and 27 Endangered plant species recognised in 2004.

37% of Socotra’s 825 plant species, 90% of its reptile species and 95% of its land snail species do not occur anywhere else in the world. The site also supports globally significant populations of land and sea birds (192 bird species, 44 of which breed on the islands while 85 are regular migrants), including a number of threatened species. The marine life of Socotra is very diverse, with 253 species of reef-building corals, 730 species of coastal fish and 300 species of crab, lobster and shrimp.One of the most striking of Socotra's plants is the dragon's blood tree (Dracaena cinnabari), which is a strange-looking, umbrella-shaped tree. Its red sap was thought to be the dragon's blood of the ancients, sought after as a dye, and today used as paint and varnish. Also important in ancient times were Socotra's various endemic aloes, used medicinally, and for cosmetics. Other endemic plants include the giant succulent tree (Dorstenia gigas), the cucumber tree (Dendrosicyos socotranus), the rare Socotran pomegranate (Punica protopunica), Aloe perryi, and Boswellia socotrana.

The island group also boasts a rich fauna, including several endemic species of birds, such as the Socotra starling (Onychognathus frater), the Socotra sunbird (Nectarinia balfouri), Socotra bunting (Emberiza socotrana), Socotra cisticola (Cisticola haesitatus), Socotra sparrow(Passer insularis), Socotra golden-winged grosbeak (Rhynchostruthus socotranus), and a species in a monotypic genus, the Socotra warbler (Incana incana).

While there are no native amphibians, the reptile species present are over 90 percent endemic to Socotra and include skinks, legless lizards, and one species of chameleon (Chamaeleo monachus). As with many isolated island systems, bats are the only mammals native to Socotra. In contrast, the coral reefs are diverse, with many endemic species. Socotra is also one of the homes of the squinting bush brown (Bicyclus anynana).

Challenges and Threats
Socotra is threatened by roading, overgrazing and overharvesting of terrestrial and marine natural resources, as well as unsustainable tourism and invasive species. Impacts of these threats on Socotra’s biodiversity need to be closely monitored and minimized. Management plans have been put in place and a sustainable financing strategy is required to ensure the necessary human and financial resources for the long-term management of the site.