Fernandina Giant-Tortoise

Reptiles of Ecuador | Testudines | Testudinidae | Chelonoidis phantasticus

English common names. Fernandina Giant-Tortoise, Narborough Island Giant-Tortoise.

Spanish common names. Galápago de Fernandina, tortuga gigante de Fernandina.

Recognition. ♂♂ 87.6 cm ♀♀ 50.7 cm. Chelonoidis phantasticus is the only species of giant tortoise known to occur on Fernandina Island. It is recognizable by its strongly saddlebacked carapace.

Natural history. Historically extremely rare. Chelonoidis phantasticus is a diurnal and terrestrial tortoise inhabiting deciduous forests. Tortoises of this species feed on grasses, herbs, shrubs, cacti.1,2


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Conservation. Critically Endangered.3 Until very recently, Chelonoidis phantasticus was only known from a single individual collected in 1906 by an expedition of the California Academy of Sciences.4 Since there are no records of whalers and buccaneers collecting Fernandina Giant-Tortoises5,6 and there are no introduced predators on the island, C. phantasticus was thought to have succumbed to volcanic activity.3,7 However, circumstantial evidence (tortoise scats, bite marks, and footprints) indicated that living individuals of the Fernandina Giant-Tortoise still existed.3 This optimistic guess has been nearly (pending genetic assignment and upcoming fieldwork) confirmed on February 2019, when an expedition led by Washington Tapia found an adult female presumably assigned to C. phantasticus. This individual is now at the Fausto Llerena breeding center in Santa Cruz Island.

How can you help the Fernandina Giant-Tortoise? The best way you can help ensure a future for Galápagos' giant tortoises is by supporting the Giant Tortoise Restoration Initiative, an incredibly ambitious effort led by Galápagos Conservancy and the Galápagos National Park, to restore tortoise populations to their historical distribution and numbers across Galápagos.

Distribution. Chelonoidis phantasticus is endemic to Fernandina Island in Galápagos, Ecuador. Although Fernandina is a 642 km2 island, only about 39–137 km2 is formed by habitat that can be potentially inhabited by tortoises.

Distribution of Chelonoidis phantasticus Distribution of Chelonoidis phantasticus in western Galápagos

Etymology. The generic name Chelonoidis comes from the Greek word chelone (meaning “tortoise”).8 The specific epithet phantasticus comes from the Greek word phantasia (meaning “illusion”),8 and it probably reflects John Van Denburgh's impression that Fernandina Island, described to him as one large cone of black lava,4 was no habitat for a real tortoise.

"...the volcano is in awful operation at present. There is one large cone which is like a large boiling pot which is boiling over. The red lava covers a field of 5 or 6 miles, which is a great illumination in the night."

Thomas Matthews, master of the whaling ship Equator, 1846.6

See it in the wild. It seems that very few individuals of Chelonoidis phantasticus still persist in the highlands of Fernandina Island, which is inaccessible to tourism. The only known living individual of the species is at the Fausto Llerena breeding center in Santa Cruz island.

Authors. Alejandro Arteaga and Juan M Guayasamin.

Academic reviewers. Adalgisa Caccone.

Illustrator. Matt Patterson.

How to cite? Arteaga A, Guayasamin JM (2019) Chelonoidis phantasticus. In: Arteaga A, Bustamante L, Guayasamin JM (Eds) Reptiles of Ecuador. Available from: www.tropicalherping.com

Literature cited.

1. Washington Tapia, unpublished data.

2. Hendrickson JR (1966) The Galápagos tortoises Geochelone Fitzinger 1835. In: Bowman RI (Ed) The Galápagos. Proceedings of Symposium of the Galápagos International Scientific Project, Berkeley, 252–257.

3. Kiester AR, Gibbs JP, Rhodin AGJ, Tapia W, Cayot LJ (2017) Chelonoidis phantasticus. The IUCN red list of threatened species. Available from: http://www.iucnredlist.org

4. Fritts TH, Fritts PR (1982) Race with extinction: herpetological notes of J. R. Slevin's journey to the Galápagos 1905–1906. Herpetological Monographs 1: 1–98.

5. Pritchard PCH (1996) The Galápagos tortoises. Nomenclatural and survival status. Chelonian Research Monographs 1: 1–85.

6. Townsend CH (1925) The Galápagos tortoises in their relation to the whaling industry: a study of old logbooks. Zoologica 4: 55–135.

7. MacFarland CG, Villa J, Toro B (1974) The Galápagos giant tortoises (Geochelone elephantopus). Part II: Conservation methods. Biological Conservation 6: 198–212.

8. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington, 882 pp.