Galapagos Giant Tortoises (Chelonoidis spp.) Fact Sheet: Population & Conservation Status

• Total number of Giant Galápagos Tortoises (GGTs)
  • 20,000-25,000 (Galápagos Conservancy 2017)
  • Historically abundant (Thorbjarnarson et al. 2000; Linda Cayot citing James Gibbs unpublished data, personal communication, 2016)
    • Estimated 200,000-300,000 before humans arrived in the Galápagos
• Population estimates (species listed in alphabetical order)
  • Chelonoidis becki (Rothschild 1901) – Wolf Volcano, Isabela
    • Several thousand (Linda Cayot, personal communication, 2016)
  • Chelonoidis chathamensis (Van Denburgh 1907) – San Cristóbal
    • More than 6,000 (Linda Cayot, personal communication, 2016)
    • First island-wide census conducted in November 2016 (galapagos.org)
  • Chelonoidis darwini (Van Denburgh 1907) – Santiago
    • More than 1,000 (Linda Cayot, personal communication, 2016; Elizabeth A. Hunter, personal communication, 2016)
    • Pre-human population: 24,000 (Cayot et al. 2016)
  • Chelonoidis donfaustoi (Poulakakis, Edwards, and Caccone 2015) – Eastern Santa Cruz
    • A few hundred (Poulakakis et al. 2015; Linda Cayot, personal communication, 2016)
    • New species, described in 2015
  • Chelonoidis duncanensis (Garman in Pritchard 1996) – Pinzón
    • About 500 (Linda Cayot, personal communication, 2016)
  • Chelonoidis guntheri (Baur in Pritchard 1971) – Sierra Negra Volcano, Isabela
    • No recent estimate
  • Chelonoidis hoodensis (Van Denburgh 1907) – Española
    • 1,000 (Gibbs et al. 2014)
  • Chelonoidis microphyes (Günther 1875) –  Darwin Volcano, Isabela
    • No recent estimate
  • Chelonoidis porteri (Rothschild 1903) – Western Santa Cruz
    • About 3,400 (range: 2,000-4,000) (Poulakakis et al. 2015; Linda Cayot, personal communication, 2016)
  • Chelonoidis vandenburghi (DeSola 1930) – Alcedo Volcano, Isabela
    • Approximately 6,300 (Cayot et al. 2018)
  • Chelonoidis vicina (Günther 1875) – Cerro Azul Volcano, Southern Isabela
    •  No recent estimate

IUCN and CITES statuses

Note: At the time of this writing, the IUCN was using the Turtle Taxonomy Working Group: van Dijk et al. (2014) for their assessments.

• Chelonoidis becki (Rothschild 1901) – Volcan Wolf Giant Tortoise
  • IUCN: Vulnerable (2015 assessment) (Caccone et al. 2017a)
  • CITES: Appendix I, as Chelonoidis niger (UNEP 2019)
• Chelonoidis chathamensis – San Cristobal Giant Tortoise, Chatham Island Giant Tortoise
  • IUCN: Endangered (2017 assessment) (Caccone et al. 2017b)
  • CITES: Appendix I, as Chelonoidis niger (UNEP 2019)
• Chelonoidis darwini – Santiago Giant Tortoise, James Island Giant Tortoise
  • IUCN: Critically Endangered (2015 assessment) (Cayot et al. 2016a)
    • Population trend: increasing
  • CITES: Appendix I, as Chelonoidis niger (UNEP 2019)
• Chelonoidis donfaustoi – Eastern Santa Cruz Giant Tortoise
  • Critically Endangered (2016 assessment) (Cayot et al. 2017a)
• Chelonoidis duncanensis – Pinzón Giant Tortoise, Duncan Island Giant Tortoise
  • IUCN: Vulnerable (2015 assessment) (Cayot et al. 2017b)
  • CITES: Appendix I, as Chelonoidis niger (UNEP 2019)
• Chelonoidis hoodensis – Española Giant Tortoise, Hood Island Giant Tortoise
  • IUCN: Critically Endangered (2015 assessment) (Cayot et al. 2017c)
  • CITES: Appendix I, as Chelonoidis niger (UNEP 2019)
  • Reduced to 15 breeders in the 1970s (Garrick et al. 2015)
• Chelonoidis porteri – (Western) Santa Cruz Giant Tortoise, Indefatigable Island Giant Tortoise
  • IUCN: Endangered (2016 assessment) (Cayot et al. 2017d)
  • CITES: Appendix I, as Chelonoidis niger (UNEP 2019)
• Chelonoidis vandenburghi – Volcán Alcedo Giant Tortoise
  • IUCN: Vulnerable (2015 assessment) (Cayot et al. 2018a)
• Chelonoidis vicina – Southern Isabela Giant Tortoise, Albemarle Island Giant Tortoise
  • IUCN: Endangered (2015 assessment) (Cayot et al. 2018b)
  • Includes synonymized
    • C. n. guentheri (Endangered C2a [1996])
    • C. n. microphyes (Vulnerable D1+2 [1996])
    • C. n. vandenburghi (Vulnerable D2 [1996])
  • TFTSG Draft 2012
    • Global: Endangered
    • Regional subpopulation (microphyes): Endangered
    • Regional subpopulation (vandenburghi): Vulnerable
    • CITES: Appendix I (UNEP 2019)
• Chelonoidis abingdonii (extinct, 2012) – Pinta Giant Tortoise, Abingdon Island Giant Tortoise
  • Extinct (2015 assessment) (Cayot et al. 2016b)
  • The last Pinta Tortoise, Lonesome George, died in managed care on 24 June 2012
  • No pure abingdonii individuals have been found
    • Tortoises with up to 50% abingdonii genes have been found from Volcan Wolf (northern Isabella)
• Chelonoidis niger (= Chelonoidis elephantopus) (extinct, ca. 1850) – Floreana Giant Tortoise, Charles Island Giant Tortoise
  • Extinct (2017 assessment) (van Dijk et al. 2017)
  • No tortoises remained on the islands of Floreana by the mid-1800s (Poulakakis et al. 2008)

U.S. Endangered Species Act status

• Endangered (since 1970)
  • Import of GGTs or their parts prohibited

Hunting and collection

• Poaching (Márquez et al. 2007)
• For local meat consumption
• Hunting prohibited by Ecuadorian government in 1933
• Can be an issue near population centers (Linda Cayot, personal communication, 2016; Elizabeth A. Hunter, personal communication, 2016)
• Primarily on Isabela Island
• C. guntheri (highest intensity of poaching), C. microphyes, C. vicinia
• Illegal take for pet and collection trades (Bonin et al. 2006)

Introduced, feral animals

• Eradication programs have been successful (Márquez et al. 2013)
• Past efforts: Isabela, Santiago, Pinta, Española, Pinzón
• Current efforts: Floreana
• Rats (Edwards et al. 2014; Jensen et al. 2015)
• Eat GGT eggs and hatchlings
• Pigs (MacFarland et al. 1974)
• Eat eggs
• Kills large numbers of juvenile GGTs
• Problem on Santa Cruz (Linda Cayot, personal communication, 2016)
• Goats (de Vries 1984; Milinkovitch et al. 2012; Márquez et al. 2013; Edwards et al. 2014)
• Destroy natural vegetation
• Compete with GGTs for food
• Reduce shade
• Other animals (MacFarland et al. 1974; de Vries 1984; Márquez et al. 2013; Edwards et al. 2014)
• Fire ants
• Problem on Santa Cruz (Linda Cayot, personal communication, 2016)
• Donkeys/burros, cattle
• Trample and roll on nests
• Dogs
• Cats

Habitat degradation

• Natural vegetation converted to farmland (Poulakakis et al. 2015)
• Conflict between tortoises and land use for crops, cattle, and horses (MacFarland et al. 1974; Bonin et al. 2006)
• Aggressive-growing introduced plant species for livestock (Blake et al. 2015b)
• E.g., blackberry and elephant grass on Santa Cruz
• Affects GGT nutritional needs and food availability (Blake et al. 2015a; Blake et al. 2015b)
• GGT movements and migrations blocked by
• Towns, villages, fences, roads, etc. (Standford 2010; Blake et al. 2013; Blake et al. 2015b)
• Overgrowth of woody shrubs (Gibbs et al. 2014)

Growing human population

• Rapid population increase since the 1950s (Instituto Nacional de Estadistica y Censos 2015)
• 1,346 people in 1950 to 25,244 people in 2015
• Limited to 3% of the land area of the Galápagos Islands (Galápagos Conservancy 2017)
• Population estimate
• Approximately 25,000 people in 2010 (National Census of Ecuador, 2010)
• Illegal immigration (Strahm and Patry 2010)
• Drivers
• Some Ecuadorians face weak economic opportunities on the mainland
• Seek “a better life” in this “tropical paradise” (Bonin et al. 2006)
• Tourism industry
• Productive fisheries

Killed as protest

• GGTs = symbols of Galápagos conservation (Orenstein 2012)
• Some people resent conservation policies
• Sea cucumber fishing quotas
• Some settlers and fisherman fighting National Park restrictions
• Tortoises and scientists threatened/held hostage (Bonin et al. 2006; Márquez et al. 2007)

Natural disasters

• Fires (Bonin et al. 2006)
• History of major fires on southern Isabela
• Destroyed habitat
• GGTs died
• Volcanic eruptions
• Isabela
• Fernandina GGTs likely extinct due to volcanism (Márquez et al. 2007; galapagos.org)
• Changes in weather patterns (Márquez et al. 2008)

Currently in practice

• Several species have recovered from near extinction (Edwards et al. 2014)
• First detailed scientific surveys conducted in the 1960s (de Vries 1984)
• Charles Darwin Research Station has managed GGT populations since 1965 (McDougal 2000)
• Habitat protections within the Galápagos National Park (MacFarland et al. 1974)
  • Park created 1959
  • Illegal to colonize natural areas
  • Prohibits the take of many animals, including GGTs and their eggs
• Hunting of GGTs prohibited since 1933 (Márquez et al. 2007)
• Restrictions on export of GGTs, both managed careand wild
• Censuses of GGT populations (Cayot 2015b)
  • Investigate population sizes, distribution, and threats to survival
• Managed breeding programs and reintroductions to the wild
  • May take decades to carry out (Milinkovitch et al. 2012; Gibbs et al. 2014)
  • Head-start programs (Standford 2010; Jensen et al. 2015)
    • Eggs or recent hatchlings collected and taken to breeding/rearing facility
      • Wide genetic diversity is important
    • Raised until 4-5 years of age (8-10 lb), then returned to island
      • Minimizes predation on hatchlings
    • Successful with Española GGTs (Milinkovitch et al. 2012; Gibbs et al. 2014)
      • Species reduced to just 15 individuals
      • Over 1,700 repatriated to the island (as of 2012)
      • Population size sustainable, but ecosystem-level health uncertain
    • 2015: Eggs of Pinzón GGTs hatch in the wild, for the first time in 150 years (Aguilera et al. 2015)
  • Possibility of selectively breeding hybrid individuals to recover extinct lineages or species (Russello et al. 2010; Edwards et al. 2013, and as noted)
    • Floreana GGTs
    • Using living individuals in managed care collections (Russello et al. 2007)
• Ecotourism
  • Touching, moving, or taking tortoises not permitted (Bonin et al. 2006)
  • GGTs on private land (Standford 2010)
    • Ranchers keep GGTs on their land
    • Tourists pay admission to see GGTs
• Access to certain islands restricted or banned (Bonin et al. 2006)
• Removal of feral animals (see Threats to Survival, above) (Márquez et al. 2013)
  • Promotes survival and growth of juvenile GGTs

Government of Ecuador

• 1959: Galápagos National Park created (Thorbjarnarson et al. 2000)
  • Illegal to take GGTs or their eggs from the islands
  • GGT populations managed by the Galápagos National Park Service
• 1998: "Galápagos Special Law" enacted and made part of Ecuador's Constitution
  • Legal framework to protect the Galápagos and create the Galápagos Marine Reserve
  • Plans for additional ecological monitoring by the Charles Darwin Research Station and Galápagos National Park Service
  • Full title: Organic Law for the Special Regimen for the Conservation and Sustainable Development of Galapagos (LOREG)

• Galápagos National Park
• Charles Darwin Foundation
  • Charles Darwin Research Station
• Galápagos Conservancy
  • Publishes Galapagos News
• Chelonian Research Institute
• Turtle Conservancy

Join San Diego Zoo Wildlife Alliance ambassador Rick Swartz, as he visits the Galapagos National Park and learns about its breeding programs.

Note: "Lonesome George" passed away about a year after this video was filmed.

© San Diego Zoo Wildlife Alliance. All rights reserved.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.