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ALDABRA

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Originally appearing in Volume V01, Page 530 of the 1911 Encyclopedia Britannica.
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ALDABRA , the collective name of a See also:

group of islands in the See also:Indian Ocean, forming See also:part of the See also:British See also:colony of See also:Seychelles. They See also:lie in 9° 3o' S., 46° E., are 265 M. N.W. of the See also:northern point of See also:Madagascar and 6go in. S.W. of See also:Mahe, the See also:principal See also:island of the Seychelles See also:archipelago. The See also:Comoro Islands lie 220 M. S. by W. of Aldabra. The Aldabra Islands, constitute an See also:atoll consisting of an See also:oval See also:ring of See also:land, some 40 M. in circumference and about 11 m. broad, enclosing a shallow `See also:lagoon. Channels See also:divide the ring into four islands. Grande Terre or See also:South Island forms three-fifths of the circumference. The other islands are See also:West Island or Ile See also:Picard, Polymnie and See also:Middle Island. There are in addition several islets in the lagoon, the most important being Ile See also:Michel. The See also:total land See also:area is estimated at about 6o sq. m., the lagoon, 16 m. See also:long and 4 M. wide, covering a somewhat larger area.

Pop. (1906) 127. The islands rise from 20 to 8o ft. above the See also:

sea, and consist of rugged See also:coral See also:rock and See also:limestone, there being very little See also:soil. The sea-See also:face is generally overhanging cliff, but in a few places are sandy beaches and See also:low sandhills. Dense scrub covers most of the land, but the inner {lagoon) See also:shore is everywhere bounded by See also:mangrove' swamps. The See also:flora and See also:fauna of the islands See also:present features of unusual See also:interest. They are chiefly noted as the See also:habitat of the gigantic land See also:tortoise (Testudo elephantina), now carefully preserved, and of several rare and See also:peculiar birds, including a See also:rail (Dryolimnas aldabranus), an See also:ibis (Ibis abbottii) and a See also:dove (Alectroenas sganzini). See also:Crustacea are abundant. They include oysters, crabs of See also:great See also:size, and a small See also:mussel, found in enormous See also:numbers. The flora includes mangroves, See also:Rubiaceae, Sapotaceae and other forms requiring more than pure coralline material for their growth. See also:Writing of the fauna and flora generally, Mr R. See also:Dupont, See also:curator of the Botanic station at Mahe, who visited Aldabra in 1906, says: " The specimens represented, besides being partly peculiar, mostly belong to the Mascarenes, Madagascar and Comoros See also:species.

Many species are also See also:

common to See also:East See also:Africa and to See also:India. . . . The predominant species are Madagascar See also:plants and birds, which are carried by the currents and the winds. .. . There are comparatively few (1o) species of plants which are endemic as far as the flora has been investigated, and it is probable that most of them are also existing in the Comoros, where the flora is not well known. . . . Endemic inferior animals and mammals are practically non-existent, except two bats and one See also:scorpion, which are allied to Madagascar species or introduced The See also:reptiles (tortoises) are also nearly allied to the Mascarenes and Madagascar species which once existed With regard to birds and land shells the relation is much closer to the Comoros species, and the latter, of which I have collected seven species besides Rachis aldabrae, may serve to point out more than the birds the ,land connexion of Aldabra with the neighbouring countries." Aldabra, however, although situated in that region of the Indian Ocean which forms part of the site of the Indo-Madagascar See also:continent of the Secondary See also:period, is not a See also:peak of the submerged land. It has been built up from the sunken remains of the old continent by a See also:deposit, in the See also:opinion of See also:Professor A. Voeltzkow, of foraminiferal remains (mostly coccoliths and rhabdoliths). In any See also:case, however Aldabra was formed, there can be no See also:suggestion of its ever having been joined to any other land (See also:Stanley See also:Gardiner). Dupont states that at Aldabra the coral See also:foundation is totally above See also:water. The coral limestone of the atoll has a peculiar vitrified See also:appearance and gives out a ringing See also:sound when struck or simply walked on.

The coral is generally reddish, but the colouring ranges from See also:

light yellow t( See also:chocolate-See also:brown. Aldabra was visited by Portuguese navigators in 1511. The islands were already known to the See also:Arabs, from whom they get their name. They became in the middle of the 18th See also:century dependencies of the See also:French establishments at See also:Bourbon (See also:Reunion), whence expeditions were made for the See also:capture of the See also:giant tortoises. In 18io with See also:Mauritius, Bourbon, the Seychelles and other islands, Aldabra passed into the See also:possession of Great See also:Britain. The inhabitants are emigrants from the Seychelles. Goats are bred and coco-nuts cultivated, but fishing is the See also:chief See also:industry. With other outlying islands Aldabra is held under See also:lease from the Seychelles See also:government, the lessees having exclusive trading privileges. See R. Dupont, See also:Report on a V i s i t o f Investigation to .. them Aldabra Group of the Seychelles Islands (Seychelles, 19o7); . Dr See also:Abbott in Proceedings, See also:United States See also:National Museum (See also:Washington, 1894) ; A. Voeltzkow in Abh. der Senckenbergischen Naturforschenden Ges. vol. See also:xxvi. part iv.

(19oi) ; J. S. Gardiner, " The Indian Ocean," Geo. Journ. Oct. 1906.

End of Article: ALDABRA

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