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Destination: Galapagos Islands Cyber Field Trip
ON THE ISLANDS

Wildlife of the Islands: Land-Dwellers


By clicking on the linked words, you can also learn more about some of the scientific terms used frequently throughout this site.

Giant Tortoise
Geochelone elephantopus
Giant TortoiseThe Galapagos giant tortoise, for which the Galapagos Islands are named, is one of the world's largest tortoises, weighing up to 500 pounds. During the 18th and 19th centuries, thousands of land-dwelling giant tortoises were carried away by sailors to supply fresh meat on ships, reducing their numbers nearly to the point of extinction. Today, these tortoises are bred and raised in captivity at the Darwin Research Station and released onto their native islands when they are able to defend themselves (at about 10 years of age). If a Galapagos tortoise can survive periods of food scarcity and avoid its major predator, the hawk, it can live for as many as 150 years! The shells of the various subspecies of Galapagos tortoise vary in shape depending on where they live and what they eat. Tortoises with saddle-shaped shells generally live on the coastal lands and are able to reach leaves from low-branched trees and shrubs. The tortoises that inhabit the highland regions have larger, dome-shaped shells and feed on grasses, plants and fallen fruit. Galapagos tortoises mate during the rainy season and nest in arid zones.

Land Iguana
Conolophus subcristatus; Conolophus pallidus
Land Iguana; photograph by Silvia SiegelThe large, dragon-like land iguana can only be found on the Galapagos Islands. Its rough, wrinkled skin is yellowish in color with scattered patches of black, brown and rust, and it may weigh as much as 15 pounds. The subcristatus subspecies can be found on five islands, mainly in dry, hot areas, while the pallidus subspecies is found only on Santa Fe. Land iguanas are territorial animals, and the males of the species are particularly aggressive toward one another. The mating habits of land iguanas vary from island to island. For food, they depend on low-growing plants and shrubs, fallen fruits and cactus tree pads. Their natural predators include hawks and owls. Land iguanas can live for more than 60 years.

Lava Lizard
Tropidurus
Lava lizard photo courtesy of Michael Jackson. Copyright 1993.Lava lizards live on most of the main islands of the Galapagos archipelago, though they differ somewhat in size, color and behavior from island to island. Seven subspecies have been identified, all of which are endemic to the Galapagos Islands. They are small creatures, growing to no more than a foot in length, and inhabit rocky areas of the islands. There they feed on beetles, spiders, ants, snails and other insects.

Now that you know about the land-dwellers life of the Galapagos Islands, find out more about the birds and marine life.


Scientific American Frontiers would like to thank Michael Jackson, author of Galapagos - A Natural History, for the use of his photos.




 

Scientific American Frontiers
Fall 1990 to Spring 2000
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