Anegada Iguana (Cyclura pinguis) Fact Sheet: Population & Conservation Status

Population estimates (in the wild)

• Total population
  • Estimated to be less than 350-400 mature adults (Bradley 2018; Bradley and Grant 2020)
• Repatriation efforts on other islands
  • Approximately 300-400 individuals on islands apart from Anegada Island (Glenn Gerber, personal communication, 2018)
• Anegada Island iguana "one of the most endangered lizards on Earth and the most endangered animal species in the British Virgin Islands" (Perry & Gerber 2006)
• Fewer than 1500 individuals estimated in 1994. (Hudson et al 1994)
• Debate exists over timing of first decline of iguana populations in Virgin Islands: (Perry & Gerber 2006)
  • Around 12,000 years ago, at end of Pleistocene; due to climate change
  • After contact with humans, first about 4,000-6,000 years ago and then beginning in 1493 by Europeans

Conservation status

• IUCN Status
  • Critically Endangered (2019 assessment) (Bradley and Grant 2020)
• CITES Status
  • Appendix I (UNEP 2019)
• U.S. Fish and Wildlife Service: Endangered (U. S. Fish and Wildlife Service 1999)
• British Virgin Islands: Protected legislation - Endangered Species Act and National Parks and Protected Areas Ordinance
• Conservation efforts on Anegada Island aided by major funding from Environment, Science, and Energy Dept. of UK Foreign and Commonwealth Office
• Lack of protected habitat inhibits release of headstarted iguanas on Anegada Island. (Perry et al 2007)
• Two strategies for current conservation programs: (Perry & Gerber 2006)
  • Habitat conservation on Anegada Island begun in 1997
  • Establishing the species on other islands that have limited development and few introduced mammals as safeguard against extinction
• Researchers suggest a management strategy to increase genetic diversity: (Alberts et al 2002)
  • Temporarily removing highest ranking males
  • Additional males then able to to breed
  • May be way to enhance diversity of small island population

Conservation history

• 1984-1986. Eight Anegada Island iguanas introduced to Guana Island, British Virgin Islands. (Goodyear & Lazell 1994)
  • Iguanas did not inhabit areas that had sheep. (Anderson et al 2010)
  • Sheep eradication effort begun in 1980s (Anderson et al 2010)
• 1990: Iguanas in the genus Cyclura chosen as highest priority for conservation efforts by American Zoo and Aquarium Association (AZA) Lizard Advisory Group (LAG) (Hudson & Alberts 2004)
• 1997: Program to conserve iguanas begun on Anegada Island with in situ headstart and release (Bradley & Gerber 2005)
• 1999: San Diego Zoo Wildlife Alliance received 3.3 adult C. pinguis from a sanctuary in Florida under management of IUCN Iguana Specialist Group and American Zoo and Aquarium Association (AZA) Lizard Advisory Group; at the time no records of other zoological facilities housing these iguanas. (Lemm et al 2005)
• 2000: Total population on Anegada, Necker, and Guana Islands estimated at fewer than 200. (Mitchell 2000b)
• 2001: 7th iguana (juvenile) came to the SD Zoo's Center for Conservation Research from a private breeder (Lemm et al 2005)
• 2002. Guana Island's relocated iguanas increased to 130 individuals. (Perry and Mitchell 2003)
• 2003: First headstarted iguanas released in wild on Anegada; 80% survived after 16 months
• 2004: Headstarted iguanas released in wild: 92% survive after 5 months
• 2005: First reproduction of Critically Endangered Anegada Island iguana at a zoo (Lemm et al 2005)
• 2009: Legislation to create a National Park on Anegada, British Virgin Islands, anticipated for core iguana area near wetlands. (Binns 2009)
• 2010: Ongoing problems with feral animals on Anegada Island
• 2010: Four zoos in the United States currently maintain 19 Anegada Island iguanas - Fort Worth Zoological Park, Houston Zoo, Zoo Miami, San Diego Zoo and San Diego Zoo Safari Park.
• 2011: In a study of genetic relatedness of a captive population at San Diego Zoo Wildlife Alliance's Safari Park, researchers learned that the six founder animals consisted of 3 pairs of closely related individuals, with each pair not closely related to the others. (Mitchell et al. 2011)
  • This information informs breeding plans for these critically endangered iguanas; additional captive iguanas from Anegada will augment this group in order to enhance genetic diversity of the offsprings

(Mitchell 2000b; Lemm et al 2005)

• Grazing of free-ranging livestock
• Predation by feral dogs
• Predation by feral cats on juveniles
• Habitat destruction
• Natural disasters, especially hurricanes

San Diego Zoo Wildlife Alliance is working in recovery efforts for this species.

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

Alberts et al. (2002)
Binns (2003, 2009)
Bradley & Gerber (2005)
Gerber (2004)
Goodyear & Lazell (1994)
Hudson et al. (1994)
Hudson & Alberts (2004)
IUCN (2004)
Mitchell (1996)
Perry & Mitchell (2003)
Perry & Gerber (2006)
U.S. Fish and Wildlife Service (1999)