By studying the natural interactions of living things, scientists can help Man to understand and conserve his environment. Aldabra affords a unique opportunity for such studies and under the Royal Society's wardenship, some 100 scientists from seven countries put in 50 man-years of research, creating a foundation upon which all future research could be based.
Aldabra's ecosystem is the only one in the world today where the dominant herbivore is a reptile, the giant tortoise (/Geochelone [Aldabrachelys] gigantea/). This survivor from the great age of reptiles exists nowhere else in such numbers. Because of competition from other animals millions of years ago, the giant tortoises died out except on remote islands. Eventually they were only to be found in the Galapagos Islands in the Pacific and several island groups in the Indian Ocean. Only the Aldabra tortoises escaped extermination on the Indian Ocean islands.
"The rescue and protection of these animals is recommended less on account of their utility ... than on account of the great scientific interest attached to them."
CHARLES DARWIN ET AL, ON ALDABRA'S GIANT TORTOISES
By investigating how the tortoises relate to other animals and plants on the atoll, it may be possible to suggest why the giant reptiles of prehistory disappeared. The tortoises also make a rewarding study in themselves, and thousands have been tagged so that population movements and individual life histories can be monitored.
"Certainly the most scientifically interesting atoll in the world oceans."
S. DILLON RIPLEY, SECRETARY, SMITHSONIAN INSTITUTION, 1967
Many of the birds are distinct species or subspecies found only on Aldabra. The most famous is the flightless White-throated rail (Dryolimnas cuvieri aldabranus), the only survivor of several flightless species, such as the dodo, once inhabiting the Indian Ocean region. Other birds unique to Aldabra include forms of the brush warbler, drongo (Dicrurus aldabranus), Comoro blue pigeon (Alectroenas sganzini) and Sacred ibis (Theskiornis bernieri). The atoll also boasts the largest breeding colony of frigate birds (Fregata minor and Fregata ariel) in the Western Indian Ocean.
Marine life is abundant. Living coral, in a multitude of colours and fantastic shapes, provides an undisturbed habitat for a wide variety of fish, animals and plants. Green turtles (Chelonia mydas), though depleted by hunting in the past, still come ashore in large numbers. Aldabra has one of the largest congregations of nesting green turtles in the Indian Ocean.
Most of the animals, as well as all the species of plants, have now been catalogued. Continuity of research is vitally important. Although some of the scientific studies have already extended or several years, they will take many more to complete. For example, the Aldabran giant tortoise can live for 150 years, so that a programme lasting several decades will be necessary if its life cycle is to be fully understood.