Natural History
Socotra
is characterized by the unique land and marine biodiversity. The is land
itself measures approximately 125 kms long by 45 kms wide and covers a
total area of 3665 sq kms. Topographically it can be divided into
three main zones: the coastal plains, a limestone plateau and the
Hagghir Mountains. 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, the 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
pomegranate. One of the most famous botanical curiosities of Suqotra is
the dragon’s blood tree (Dracaena cinnabari) which is restricted to the
zones of submontane thicket and montane grassland. The tree is so named
because any injury to the bark results in a deep red liquid exuding from
the scar. It 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 the Arabic.
 Flora
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. To date, approximately 900 vascular plants have been recorded from
Socotra, of which between 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 which long ago disappeared
from the African/Arabian mainland.
Socotra’s flora has strong links with adjacent parts of Somalia and Arabia
but some species and genera have interesting disjunctive distributions:
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 but perhaps the most strange distribution is that
shown by the genus Thamnosma with T. socotrana on Soqotra and related
species in southern Arabia, south-west Africa and south-west North America.
Socotran’s flora includes plan ts which can be considered taxonomic relicts,
that is with no close relatives, these include: Dirachma socotrana, one of
only two species in the Dirachmaceae, a family related to the Malvaceae but
with an interesting mixture of characters including 8 merous flowers,
stamens opposite the petals and fruits with a dehiscence similar to that
found in Geranium; Dendrosicyos Soqotranus the only arborescent member of
the Cucurbitaceae and Wellstedia a small shrub of boraginaceous affinities
but which 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 somewhat resembles a
small baobab; Dorstenia gigas and Adenium obesum ssp. socotranum. One of the
most interesting trees, and an important potential genetic resource is
Punica protopunica. This is related to the pomegranate (P. granatum) but has
smaller and less palatable fruits and is the only other species in the
family Punicaceae. Several species on Socotra are of horticultural interest
for instance 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).
 Fauna
Socotra's
fauna is just as fascinating. Among the land birds Socotra Island is ho me to
180 species of birds 6 species are endemic, ((Socotra sparrow – Socotra Cisticola – Socotra Starling – Socotra Sun bird –Socotra Warbler – and the
rarest Socotra Bunting ( estimated with 1000 specimens alive) )). as well
as 14 sub-species, are restricted to Socotra. And also it’s a host point for
many immigrated/breeding birds of over 45 species such as Flamingos, Kettle
Egrets, Reef Hearns, Gulls, etc. And the highest density in the world for
Egyptian Vulture has registered on the island.
More
work is still needed to clarify the status of other species.
There are 190 species of butterfly and with a large number of endemics. The
reptil ian and insects fauna is also very rich 600 species of insects with
90% with high proportion of endemic.
The reptilian fauna is also very rich
with 19 out of a total of 22 species regarded as endemics.
Goats, shapes, caws, donkeys, and camels are common to come across. Bats
and
civil cat is the only mammals native to the island.
In
the marine world Socotra has taken a spectacular place as it has mixture of
specie s from different biogeography regions- the western Indian Ocean, the
Red sea, East Africa and the wider
Indo-Pacific. Despite of the small
archipelago, Socotra Island is home to more than 680 Species of fishes are
comparable to those of the Red Sea. and about 230 species of hard corals
(five are endemics) and 30 species of soft corals. In addition to 300
species of crustacean (nine are endemics), 490 species of mollusks, and 230
species of algae. Sea-turtles also nest on the north of the island but there
is a need for more work on these (as with almost all Socotra's wildlife). An
endemic fresh-water crab, Potamon socotrensis, is common in the temporary
water-courses. In general the fresh-water habitats of the island have been
little studied and it i s still not clear whether there are endemic
freshwater fish living there. Among the insects it is not surprising to find
many forms with reduced wings, lessening the likelihood that they are 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 the granitic Seychelles and even some remote islands of the Atlantic
Ocean. There remains a great need for further studies of individual species
and of main habitats on Socotra. To date, for example, there has been very
little work done on the southern and western plateau, the more isolated granitic pinnacles, as well as the major part
 of the islands' coastal
waters.
Its
unique character makes Socotra a natural World Heritage site. In practice
however what matters is the effect on the ground. There is little doubt that
potential revenue sources for
the local population must be developed and
these may include small-scale tourism, the 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
Soc otra the continued survival of many endemic species, and of unique
habitats is at risk. Socotra provides both an opportunity and a challenge
for mankind. Fortunately the concept and value of conservation is still high
on the agenda of the island's people. It is to be hoped that local and
national efforts to protect Suqotra's unique wildlife are supported by
international assistance and that the island's uniqueness is maintained for
the benefit and pleasure
of future generations.
The
floras of oceanic island are often particularly rich in species and show a
high degree of endemism. Socotra is no exception. It has one of the richest
island floras in the world - on a par with those of the Galapagos,
Mauritius, Juan Fernandez and the Canary Islands. However, island ecosystems
are often fragile and their native species vulnerable to overgrazing from
introduced herbivores and to being out-competed by exotic plant species.
The
threats to the Socotran flora can be illustrated by considering the fate of
the vegetation on other oceanic islands. The decimation of Dracaena draco on
the Canary Islands and Madeira is a particularly relevant example. On
Socotra Dracaena cinnabari is widespread over the centre and east of the
island and is the dominant tree in some areas. In the Canary Islands its
closest relative, D. draco, is reduced to five trees on Madeira and is
extinct on four of the seven Canary islands with no more than 200 trees
surviving on the other three islands. On St Helena the vegetation has been
almost totally decimated. Goats were introduced on to the island in 1513. By
1800 the forests which originally covered the islands were reduced to a few
remnants and it has been estimated that, of the probable 100 endemics on the
island, only 40 now remain.
There were undoubtedly drastic changes to the vegetation and widespread
extinctions in the past but now a balance seems to have been established
between man and nature. There is no evidence to suggest that the situation
on the island has changed much since Balfour's visit in 1880. There seem to
have been no extinctions since Balfour's time and certainly the suggestion
that the island's flora has been decimated by huge goat herds (Lucas et al.
1978 etc.) is totally unfounded. However, proposed development on the island
could see the situation deteriorate very rapidly.
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