Galápagos Giant Tortoise
GALAPAGOS GIANT TORTOISE The Galápagos giant tortoise (Chelonoidis nigra) is the largest living tortoise species. Weighing up to 250kg (550 pounds) and numbering perhaps 200,000 before humans discovered the islands, their huge size led 16th-century Spanish explorers to apply their Spanish name to the whole archipelago. The islands’ dominant plant eater, they play an important role as their habitats’ top grazer. In the wild, these gentle giants slowly barrel their way through the plant cover. The shape of their shells varies from island to island and, on Isabela, from volcano to volcano. Islands with humid climate have larger tortoises with domed shells and shorter necks; dry climates lead to somewhat smaller tortoises with “saddleback” shells and long necks. Growing slowly, they often live to become well over 100 years. Hunting by whalers and others took a steep toll on the giant tortoises and their numbers plunged, with five of fifteen subspecies becoming eradicated. Breeding programmes have however led to a recovery, and Galápagos giant tortoises now number close to 20,000. Rats and feral cats and dogs still pose a threat to nests, attacking eggs and freshly hatched tortoises. Young tortoises are therefore kept until they have grown large enough to be safely released into the wild. Visitors can see them in their natural habitat in the highlands of Santa Cruz and also at breeding centres in Puerto Ayora.