Large numbers of C. n. darwini were removed from Santiago Island in the early 19th century by whaling vessels, and introduced goats reduced the coastal lowlands to deserts, restricting the remaining tortoises to the interior. The sex ratio is strongly imbalanced in favour of the males, and most nests and young are destroyed by feral pigs. Some nests are now protected by lava corrals, and since 1970, eggs have been transported to the Charles Darwin Research Station for hatching and rearing. Release programs and measures for nest protection from feral pigs have been successful.[7] There are approximately 1,165 individuals in the wild, with an increasing population.[3]
The C. n. darwini are diurnal and terrestrial. Their habitats include deciduous forests, evergreen montane forests, and humid grass land.[8] At maturity they reside in the highlands of Santiago Island in the Galapagos.[8] However, in the first 10-15 years of their lives the remain in they lowlands of the island.[8]
The gray to black carapace of C. n. darwini is intermediate in shape between the saddle-backed subspecies and the domed subspecies of Galápagos tortoises. It has only a shallow cervical indentation. The anterior carapacial rim is not appreciably upturned, and the posterior marginals are flared, slightly upturned, and slightly serrated.[citation needed]
The diet of the C. n. darwini consists of cacti, herbs, and grass found on Santiago Island.[8] The water in their diet is obtained by the vegetation they consume or by temporary pools.[8]
^Cayot LJ (1994). "Conservation biology of Galápagos reptiles: twenty-five years of successful research and management". pp. 297–305. In:Murphy JB, Adler K, Collins JT (editors). Captive Management and Conservation of Amphibians and Reptiles. Ithaca, New York: Society for the Study of Amphibians and Reptiles. Contributions to Herpetology. Vol. 11. ISBN0-916984-33-8.
Van Denburgh J (1907). "Expedition of the California Academy of Sciences to the Galapagos Islands, 1905–1906. I. Preliminary descriptions of four new races of gigantic land tortoises from the Galapagos Islands". Proceedings of the California Academy of Sciences, Fourth Series1: 1–6. (Testudo darwini, new subspecies). (Full text).
