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

Population 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    • Historically abundant (Thorbjarnarson et al. 2000; Linda Cayot citing James Gibbs unpublished data, personal communication, 2016)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
    • Chelonoidis hoodensis (Van Denburgh 1907) – Española
      • 1,000 (Gibbs et al. 2014)
    • Chelonoidis microphyes (Günther 1875) –  Darwin Volcano, Isabela
    • 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
      •  

Conservation Status

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
  • 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 (2015 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

Threats to Survival

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)

Management Actions

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)

 

Conservation Groups

Galapagos Tortoise Conservation

Join San Diego Zoo Global 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 Global. All rights reserved.

Galápagos Tortoise

a Galapagos Tortoise up close

Image credit: © San Diego Zoo Global. All rights reserved.

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