ISLAND OF DRAGONS SOCOTRA
Text and pictures by Wolfgang Wranik
ON MAP TO ENLARGE (54k JPEG)
“Dioscorida
is very large but desert and marshy, having rivers in it and crocodiles
and many snakes and great lizards, of which the flesh is eaten and the
fat melted and used instead of olive oil” – thus commented the
author of the Periplus of the Erythraean Sea, a shipping manual written
by an unknown Greek sailor in the first century AD. The island that he
was describing was Socotra which today forms part of the Republic of Yemen
and was, towards the end of 1993, the subject of a UNESCO fact-finding
mission to consider the establishment of this unique island as a Biosphere
Reserve.
Apart
from some 19th century travel accounts and a few more recent expeditions,
including a British joint-services and civilian expedition in 1967 (see
Socotra: Island of Tranquillity, by Brian Doe, published by Immel Publishing,
1992) the Socotra archipelago has received relatively little attention
from the scientific community, being virtually isolated from the rest of
the world and effectively closed to foreign visitors for the last quarter
century or so by a combination of military considerations and extreme natural
conditions. The south-west monsoon, which kicks up high seas in the area
from April to October, has created a physical barrier to access since earliest
times. Even during the calmer periods landing there may still be difficult
due to a combination of logistical problems, including the absence of adequate
harbour facilities.
The crocodiles and giant lizards referred to by
the author of the Periplus are no longer present there today. No fossils
have so far been discovered but this is not to say that they did not exist.
Indeed, the Indian Ocean crocodile survived right up to the 17th century
AD when it was described by sailors visiting the Seychelles, which lie
1,600 kms due south. Such lost inhabitants apart however, Socotra remains,
from a natural history viewpoint, one of the most fascinating places in
the world. Its unique character is the result of a long period of isolation
– its separation from Africa is believed to have occurred in the mid-Pliocene
(approx six million years ago). As a result, many animals and plants that
live today on Socotra are found nowhere else on earth. The very high degree
of endemism is what makes Socotra such an important place in terms of global
wildlife conservation. It is believed that some of the plants and animals
found on Socotra are in fact ancient relicts of a much larger land mass
which have been preserved here as a result of the fact that the Haghir
massif has not been totally submerged for at least 135 million years. The
absence of any indigenous mammals is further indication of the island’s
very ancient origins, presumably from a time before mammals appeared on
earth.
The
island itself measures approximately 120 kms long by 40 kms wide and covers
a total area of 3625 sq kms. It is composed of a basement complex of igneous
and metamorphic rocks of pre-Cambrian age (4,500 million years ago), overlain
by sedimentary rocks, mainly limestone and sandstone. Topographically it
can be divided into three main zones: the coastal plains, a limestone plateau
and the Haghir mountains. The island is sparsely vegetated and dominated
by xeromorphic (drought resistant) forms which are well adapted to the
harsh conditions, including the dessicating 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 of a variety of frankincense trees,
three endemic Socotran aloes (primarily Aloe perryi), and wild pomegranate.
One of the most famous botanical curiosities of Socotra 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 – compared
in the past to the “blood of dragons”.
To
date, 815 vascular plants have been recorded from Socotra, of which between
230 and 260 are found nowhere else (i.e. endemic species). 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. Plant extracts are still
used in medicines, cosmetic and hygiene preparations, in the manufacture
of cordage, as a source of insecticide and in tanning and dyeing.
Socotra’s fauna is just as fascinating. Among
the land birds at least four species, as well as 14 sub-species, are restricted
to Socotra. More work is still needed to clarify the status of other species.
The reptilian fauna is also very rich with 19 out of a total of 22 species
regarded as endemics. Sea-turtles also nest on the north-east 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 is 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 potential
candidate for designation as either a natural World Heritage Site or a
MAB Biosphere Reserve. In practice however what matters is the effect on
the ground. A general designation of island-wide protective status would
cause problems locally and would not address the challenge of achieving
sustainable development. 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
programmes. Among the steps that could assist this process would be the
establishment of a permanent research station at Hadibo, connected with
a plant nursery and arboretum.
Given the social and developmental pressures which
are now a fact of life on Socotra 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 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.