Socotra Islands Wildlife
Many theories exist regarding the unique nature of the flora and fauna on the Islands of Socotra. A popularly held belief is that the original species that evolved into the unique Socotra variety found their way to the islands on flotation rafts of vegetation and other waste and were carried to the island via wind and sea currents.
Socotra Island Animals & Plants
The island is sparsely vegetated and dominated by xenomorphic (drought resistant) forms which are well adapted to the harsh conditions, including the desiccating effects of sun and wind. Only in sheltered valleys and higher mountain areas is the vegetation more luxuriant.
Open deciduous shrubland of the coastal plains and low inland hills is dominated by the common shrub Croton socotranus and the bizarre tree succulents, desert rose, Adenium obesum socotranum, and the cucumber tree, Dendrosicyos socotranus.
Higher altitudes are home to a variety of frankincense trees, three endemic Suqotran aloes, and wild pomegranates.
One of the most famous botanical curiosities of Socotra is the dragon blood tree (Dracaena cinnabari) which is restricted to the zones of a submontane thicket and montane grassland. The tree is named because any injury to the bark results in a deep red liquid exuding from the scar. Dragon’s blood tree was compared to the “blood of Abel” in ancient history. It is called Dum al Axwein, “blood of the two brothers” Cain and Abel, in the present-day Arabic language. The Suqotri name “Arriyahib” has no connection to Arabic.
Scientists first reached the remote Socotra Archipelago in 1880, when Scottish botanist Isaac Bailey Balfour collected around 500 plants. Over 200 were species new to science. Approximately 900 vascular plants have been recorded from Socotra, of which 300(including some fifteen species restricted to Abd al Kuri) are found nowhere else (i.e. endemic species). They create weird vegetation – and make the archipelago the world’s tenth richest island group for endemic plant species.
Many are strange-looking remnants of ancient floras that disappeared from the African/Arabian mainland long ago.
Socotra’s flora links with the adjacent parts of Somalia and Arabia, but some species and genera have interesting differences.
Dracaena cinnabari – the Dragon’s Blood tree is a tertiary relict with related species in southern Arabia, north-east Africa and the Canary Islands.
Species of Kalanchoe and Helichrysum show strong links with southern African species. The strangest difference is that shown by the genus Thamnosma with T. socotrana on Socotra and related species of south Arabia, south-west Africa and south-west North America.
Socotran’s flora includes plants which can be considered taxonomic relics with no close relatives. These include Dirachma socotrana – one of only two species in the Dirachmaceae (a family related to the Malvaceae) but with interesting differences – including eight merous flowers, stamens opposite the petals and fruits with dehiscence similar to that found in Geranium. Dendrosicyos Soqotranus – the only arborescent member of the Cucurbitaceae and Wellstedia, a small shrub of boraginaceous affinities that is sometimes placed in a family of its own.
There is one sub-endemic family – the Dirachmaceae (recently a second species has been found in Somalia) and ten endemic genera: Angkalanthus, Ballochia and Trichocalyx (Acanthaceae), Duvaliandra and Soqotranthus (Asclepiadaceae), Haya (Caryophyllaceae), Lachnocapsa (Cruciferae), Dendrosicyos (Cucurbitaceae), Placoda (Rubiaceae) and Nirarathamnos (Umbelliferae). The families richest in endemics are Compositae (26), Acanthaceae (24), Euphorbiaceae (21), Labiatae (20) and Asclepiadaceae (11).
Perhaps the most notable of these are the podagrics or swollen-stemmed trees. These include Dendrosicyos socotranus, which resembles a miniature baobab; Dorstenia gigas and Adenium obesum ssp. socotranum. One of the most interesting trees and a vital potential genetic resource is Punica protopunica. It is related to the pomegranate (P. Granatum) but has smaller and less edible fruits and is the only other species in the family Punicaceae. Several species on Socotra are of horticultural interest, for example, Begonia socotrana, the hybrid parent of winter-flowering begonias, and Exacum affine, the Persian violet.
The least studied groups are the lichens, bryophytes and fungi. The people living on Socotra, especially the Bedouins, have a thorough knowledge of the flora, and many of the plants have traditional uses, such as providing livestock fodder, fuel, building materials, foods, gums, or resins. The majority of islanders still rely on livestock – and thus of necessity on the vegetation – for their survival. And the many sheep, goats, camels, cattle and donkeys of the island are supported solely by the island’s vegetation.
Plant extracts are still used in medicines, cosmetic and hygiene preparations, and in the manufacture of cordage, as a source of insecticide, and in tanning and dyeing. (Click hear to learn more about the flora traditional uses).
Socotra Island Animals
Socotra’s animal life (or fauna) is just as fascinating as its flora. Among the land birds, Socotra Island is home to 180 species of birds – out of which eleven are endemic:
1) Socotra Sparrow
2) Socotra Cisticola
3) Socotra Starling
4) Socotra Sunbird
Socotra is also a host point for many immigrated/breeding birds of over 45 species such as Flamingos, Kettle Egrets, Reef Hearns, Gulls, etc. The highest density in the world for Egyptian Vulture has been recorded on the island.
Socotra island measures 125 km long by 45 km wide and covers a total area of 3665 sq km. Topographically it can be divided into three main zones: the coastal plains, a limestone plateau and the Hagghir Mountains.
There are 190 species of butterfly and a large number of endemics. The reptilian and insect fauna is also vibrant, with 600 species of insects with 90% with a high proportion of endemic. The reptilian fauna is also dynamic, with 19 out of 22 species being endemic.
Among Socotra animals, Goats, shapes, caws, donkeys, and camels are common. Bats and civil cat is the only mammal native to the island.
Socotra has taken a spectacular place in the marine world as it has a mixture of species from different biogeography regions – the western Indian Ocean, the Red sea, East Africa and the wider Indo-Pacific.
Despite the small archipelago, Socotra Island is home to more than 680 species of fish that are comparable to the Red Sea. There are about 230 species of hard corals (five are endemics) and 30 species of soft corals.
Three hundred species of crustaceans (nine are endemics), 490 species of mollusks and 230 species of algae are also found on the island. Sea turtles nest on the north of the island, but there is a need for more research on them (as with almost all Socotra’s wildlife).
An endemic freshwater crab: Potamon socotrensis is common in the temporary Socotra water bodies.
The freshwater habitats of the island have been little studied and it is still unclear whether endemic freshwater fish are living there. Among the insects, it is not hard to find many forms with reduced wings, lessening the likelihood of being blown off the island.
From a biogeographic perspective, Socotra is more closely linked with Africa than Arabia, but there are also interesting affinities with other island groups such as granitic Seychelles and some remote islands of the Atlantic Ocean. There is a great need for further studies of individual species and main habitats on Socotra.
Very little work has been done on the southern and western plateau (the more isolated granitic pinnacles) and a significant part of the islands’ coastal waters.
Its unique character makes Socotra a natural World Heritage site. However, what matters is the effect on the ground. Potential revenue sources for the local population must be developed, including small-scale tourism, cultivation and export of native plants or the collection and storage of seeds and cuttings for propagation as part of international programs.
Given the social and developmental pressures which are now a fact of life on Socotra, the continued survival of many endemic species and unique habitats is at risk. Socotra provides both an opportunity and a challenge for humanity. Fortunately, the concept and value of conservation are still high on the agenda of the island’s people.
It is hoped that local and national efforts to protect Socotra’s unique wildlife are supported by international assistance and that the island’s uniqueness is maintained for the benefit and pleasure of future generations.
