TheFloreana giant tortoise (Chelonoidis niger niger), also known as theCharles Island giant tortoise, is asubspecies of theGalápagos tortoiseendemic to theGalápagos archipelago in theequatorial easternPacific Ocean. Thespecific epithetniger (‘black’) probably refers to the colouration of theholotype specimen.[2] The species name has often been misspelled asnigra, an error introduced in the 1980s whenChelonoidis was elevated to genus and mistakenly treated as feminine, an error recognized and fixed in 2017.[3]
In 2012,hybrids of the subspecies withChelonoidis becki were discovered onIsabela Island. Since then,back breeding has been used torecreate the original subspecies and help it regain its genetic purity.[4] As of 2025, 400 tortoises have been hatched in captivity onSanta Cruz Island.[5][6] However, theIUCN has yet to update the subspecies' status due to lack of a genetically pure specimen at the time of the 2017 evaluation.[7]
The tortoises used to descend to the lower slopes of their volcanic island to graze on new vegetation after wet season rains. They fed on grass,bitterbush andcacti, obtaining water from springs and from cracks in thelava rocks.[2]
The tortoise's natural range was limited to 173 km2 (67 sq mi)Floreana Island (formerly Charles Island) where it inhabited deciduous and evergreen forests.[2]
The tortoise population of Floreana is estimated to have originally comprised some 8,000 individuals. Extinction occurred during the 1840s or 1850s following overexploitation for food by sailors and settlers, as well as predation and habitat degradation fromintroduced species, includinggoats,pigs,dogs,cats,donkeys, androdents.[2] Also blamed for the extinction was a massive wildfire on Floreana in 1820, initially started as a prank by Thomas Chappel, a crewman on the whaling shipEssex (best known for being sunk by asperm whale shortly afterwards, inspiring the novelMoby-Dick). By the timeCharles Darwin arrived in 1835, decades of exploitation had driven the population to critically low levels, with Darwin recording that about 20 years worth of harvestable tortoises were left. The tortoises finally disappeared around 1850.[9][10][11]
In 2012, severalhybrids between this species andChelonoidis becki were discovered aroundWolf Volcano onIsabela Island, apparently from some of the Floreana tortoises being transported there in the early 19th century.[12][4] In 2017, a breeding program began toresurrect the Floreana subspecies.[2][4] By 2023, about 400 Floreana tortoise offspring had been produced from the breeding program, and there are plans toreintroduce some of these to Floreana in 2024, as part of arewilding programme following the successful removal ofinvasive species from the island in December 2023.[13][6] However, IUCN has yet to update the status of the subspecies due to lack of a genetically pure specimen at the time of the 2017 evaluation and the de-extinct subspecies has yet to reproduce naturally in the wild.[14]
^(N/A), Peter Paul van Dijk; Foundation), Anders Rhodin (Chelonian Research; Conservancy), Linda Cayot (Galapagos; University), Adalgisa Caccone (Yale (2017-01-25)."IUCN Red List of Threatened Species: Chelonoidis niger".IUCN Red List of Threatened Species.Archived from the original on 2024-07-10. Retrieved2025-01-01.
