GA'LAPA'GOS ISLANDS (Sp. pron. litlxl-gOs), (Sp., tortoise). A group of small vol canic islands in the Pacific Ocean, crossed by the equator and extending from about longitude 89° to 92° W., about 600 miles west of Ecuador, to which it belongs (Map: Ecuador, A 8). It con sists of the larger islands of Albemarle, Inde fatigable, Chatham, James, and Charles, and a number of smaller islands. The total area of the group is estimated at 2400 square miles, of which Albemarle occupies over one-half. The islands are volcanic in origin and mountainous. There are supposed to exist a number of more or less active volcanoes. The climate is less hot than is usual iu regions of that latitude, and the flora, though not rich, is interesting, including species peculiar only to the group or even to separate islands. Turtles are very numerous and form the chief product of the islands. There is some sugar growing on the island of Chatham, and cattle are raised to some extent. The population is about 400. The Galapagos group was known as early as the sixteenth century, and was afterwards fre quently visited by buccaneers, to whom the isl ands are probably indebted for their English names. They were annexed to Ecuador in 1832, and explored by Darwin in 1858.
The Galapagos Islands are of extreme interest to zoologists, in view of the peculiarities of their fauna, and the bearing the facts have upon the evolutionary history of animals. It was the observation of them, during the voyage of the Beagle, which more than any other set of facts, perhaps, led Darwin to his subsequent specu lations; and they figure largely in the reasonings of himself, Wallace, and all other evolutionists. While in general the fauna resembles that of South America (see NEOTROPICAL REGION), it is remarkable for having almost no species in common with the continent, and a great paucity of all forms of life except birds. The flora of the group is scanty, and more than half of its species are found nowhere else; so that it is natural to find that the land-shells, insects (mainly beetles), etc., are few and peculiar. Reptiles arc represented by the famous giant tortoises, two species of snake, and four lizards. Of the last, two are of genera confined to the islands. One is a large burrowing iguanid, and the other 'an aquatic modification' of the same, having a semi-marine life and subsisting on sea weeds. The giant tortoises, now greatly decreased in
numbers, were formerly extremely numerous and tame, and reached a huge size. (See ToarotsE.) The islands were named after them, and there were several species, each inhabiting a separate part of the archipelago. The only mammals were a mouse and a rat, which there is much reason to believe escaped from some early ship, and had time to become modified by the time they were discovered by naturalists. Birds abound, and present many interesting facts. While their resemblance on the whole is to the avifauna of Central and South America, some extraordinary relationships to the Hawaiian fauna, are apparent. Forty-six genera, according to Ridgway (1896), are represented on the islands, twenty-eight of which are water-birds wandering throughout the American tropics. One rail (Nesofelia) is peculiar, and a sand piper is known elsewhere only in the Sandwich Islands. Of the thirteen genera of land-birds, six are also represented in South and Central Amer ica, one (the bobolink) in North America, and four genera are peculiar: two of them are thrush like birds, and two are ground sparrows. These genera include a large number of species not known outside of the archipelago. A striking feature in all branches of the local zoology' is the specific disparity between animals peculiar to the different islands, each of which has its own kind. The various facts lead to the belief that an immense period of time has elapsed since the islands were colonized; that this must have gone on very slowly and accidentally (except in the case of most birds), and at long intervals; and that to a great extent there has been no intercommunication of animal life between the various islands. The archipelago is also a most fruitful illustration of insular influences on ani mal life and of the effects of isolation (q.v.). Consult: Darwin, A Naturalist's Voyage (Lou don, 1866) ; Wallace, Geographical Distribution of Animals (New York, 1876) ; Salvin, Transac tions of the Zoological Society, vol. ix. (London, 1876) ; Ridgway, "Birds of the Galapagos," in Proceedings of the United States National Mu seum, vol. xix. (Washington, 1896), and its bib liography.