Cyclura pinguis

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Cyclura pinguis
Cyclura pinguis2.jpg
In the wild on Anegada
CITES Appendix I (CITES) [2] [note 1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Iguanidae
Genus: Cyclura
Species:
C. pinguis
Binomial name
Cyclura pinguis
Barbour, 1917

Cyclura pinguis, the Anegada rock iguana, Anegada ground iguana or stout iguana, [3] is a critically endangered species of lizard of the genus Cyclura belonging to the family Iguanidae. The species can be found exclusively in the islands of Anegada and Guana. Historically, it inhabited the islands of Puerto Rico and Saint Thomas; however, the animal's original range has been greatly diminished over prehistory. [4]

Contents

Natural history

The Anegada ground iguana is noted as the oldest species of Cyclura and the most genetically divergent of the West Indies' rock iguanas. [5] [6] An ancestor to this iguana first dispersed to Hispaniola, then onwards to the north and western islands, which has since diversified on different islands into the 9 species and several additional subspecies of the genus Cyclura as we know it today. [7]

Taxonomy

The Anegada ground iguana was first described by American Herpetologist Thomas Barbour 1917. [8] [9] Its specific name pinguis means "fat" and refers to the animal's stocky appearance and the common name "Stout iguana". [9]

Anatomy and morphology

The Anegada ground iguana is a large heavy-bodied rock iguana which attains a total body length of close to 22 in (560 mm). [4] As juveniles they are faintly or boldly patterned with wide gray to moss green bands interspersed with wide gray to black anteriorly directed chevrons. These bands fade and are generally lost as the animals mature, turning a uniform grayish or brownish-black with varying amounts of turquoise on the dorsal spines, tail base, fore and hind legs. Occasionally this bluish coloration extends up onto the sides of the individual, particularly in males. Females tend to be relatively dull in color, exhibiting less brilliant blue if any.

This species, like other species of Cyclura, is sexually dimorphic; males are larger than females, and have more prominent dorsal crests, "horns" and femoral pores on their thighs, which are used to release pheromones. [10] [11]

Diet

Like all Cyclura species the Anegada ground iguana is primarily herbivorous, consuming leaves, flowers and fruits from different plant species. [4] However, due to direct competition with grazing livestock in its native habitat such as sheep, goats, burros, and cattle they have been reduced to eating vegetation rejected by these domestic and feral animals. [4] [5] This has also caused them to become opportunistic carnivores preying upon centipedes, millipedes, roaches, insects, and other invertebrates as opposed to being strict herbivores. [4]

Mating and habitat

At the Houston Zoo Stout Iguana.jpg
At the Houston Zoo

This forced diet has affected the iguanas' ability to reproduce. [4] As reproductive females are not being provided with enough nutrition to produce eggs and support their own metabolism; many do not survive after laying eggs, resulting in the present skewed sex ratio of 2 males to every female. [4] Females usually lay one clutch of about 1216 eggs per year in late spring or early summer. [4] [5]

Anegada Island is rare in that it is not a volcanic island, but formed from coral and limestone providing many caves and natural burrows for the iguanas to live. [4] Animals typically inhabit a single burrow and it was once observed that they appeared to bond for life, dwelling in burrows in close proximity to their mate. [4] As the drive to find more females and compete for food has increased their range, this does not appear to be occurring any longer. [4]

Conservation

Endangered status

It is estimated that the current global population is less than 300 and is rapidly declining: the population has decreased by at least 80% over the last 40 years. [4] [5] [12] [13]

Causes of decline

In the brush Cyclura pinguis1.jpg
In the brush

The primary reason for the Anegeda ground iguana's decline is competitive grazing with domestic and feral livestock. [4] [5] The secondary reason is that they are preyed upon by feral dogs and cats. [4] [5] [12] As with other Rock Iguanas, their habitat is also in rapid decline due to development and logging. [4]

Live Anegada iguanas used to regularly be sold to tourists as pets, as their rarity made them more appealing to exotic animal collectors, despite this being illegal under the CITES treaty. [14] In 1999 a World Wildlife Fund international conservation officer, Stuart Chapman, said: "The British government has turned a blind eye for over 20 years to these overseas territories which are home to many rare and endangered species. Many of these face extinction if Britain fails to honour its treaty obligations. The British Caribbean islands are extremely rich in biodiversity with many critically endangered species that are unique to the islands - yet there is virtually zero enforcement or implementation of CITES." [14]

Recovery efforts

Intense conservation efforts are underway to protect this species. [6] In the 1980s, eight iguanas were moved from Anegada to Guana Island, British Virgin Islands, to start a second population in part of the species' former range. [4] [15] Guana Island is not a limestone island, and does not provide as many natural retreats as Anegada does. The iguanas appear to be doing well and reproducing in areas free of feral sheep, which is its only competitor for vegetation. Approximately 20 adult iguanas are estimated to inhabit Guana and offspring have been seen each year since 1987. [4] Guana Island Wildlife Sanctuary continues to try to rid the island of sheep, which may improve the habitat for iguanas. [4]

The Anegada ground iguana has also been successfully bred in captivity at the San Diego Zoo and the Fort Worth Zoo. [12] Both zoos have actively been working with the British Virgin Islands on a joint-recovery program started in 1997 on Anegeda Island. [12] 120 iguanas have been raised at the facility for release into the wild. [12] Hatchlings are fed and protected so they can be "headstarted" for the wild and not fall prey to feral dogs and cats. [12] This offsets the juvenile mortality rate and is accompanied by field research, nest site protection, and monitoring of released animals. [12] [16]

Notes

  1. Except populations of Australia, Indonesia, Malaysia and Papua New Guinea which are included in Appendix II.

Related Research Articles

<span class="mw-page-title-main">Anegada</span> Northernmost of the British Virgin Islands

Anegada is the northernmost of the British Virgin Islands (BVI), a group of islands that form part of the archipelago of the Virgin Islands. It lies approximately 15 miles (24 km) north of Virgin Gorda. Anegada is the only inhabited British Virgin Island formed from coral and limestone, rather than being of volcanic origin. While the other islands are mountainous, Anegada is flat and low. Its highest point is only about 28 feet (8.5 m) above sea level, earning it its name, which is the Spanish term for the flooded land, "tierra anegada".

<span class="mw-page-title-main">Turks and Caicos rock iguana</span> Species of lizard

The Turks and Caicos rock iguana is a species of lizard endemic to the Turks and Caicos islands. This small iguana can reach 30 in (76 cm) and becomes mature at seven years and may live for twenty. A single clutch of up to nine eggs is laid each year, and these take three months to hatch. This iguana is mostly herbivorous, but supplements this by adding some animal matter to its diet.

<span class="mw-page-title-main">Blue iguana</span> Species of reptile

The blue iguana, also known as the Grand Cayman ground iguana, Grand Cayman blue iguana or Cayman Island rock iguana, is an endangered species of lizard which is endemic to the island of Grand Cayman. It was previously considered to be a subspecies of the Cuban iguana, Cyclura nubila, but in a 2004 article Frederic J. Burton reclassified it as a separate species because according to him the genetic differences discovered four years earlier between the different C. nubila populations warranted this interpretation. The blue iguana is one of the longest-living species of lizard.

<span class="mw-page-title-main">Mona ground iguana</span> Species of Cyclura closely related to the rhinoceros iguana

The Mona ground iguana is a critically endangered species of rock iguana, endemic to Mona Island, Puerto Rico. It is one of the island nation's few large land animals, and it is the largest endemic terrestrial lizard in the country, and one of the biggest rock iguanas within the Antilles. It was previously considered a subspecies of the rhinoceros iguana.

<span class="mw-page-title-main">Jamaican iguana</span> Species of lizard

The Jamaican iguana, also known commonly as Colley's iguana, is a large species of lizard in the family Iguanidae. The species is endemic to Jamaica. It is critically endangered, even considered extinct between 1948 and 1990. Once found throughout Jamaica and on the offshore islets Great Goat Island and Little Goat Island, it is now confined to the forests of the Hellshire Hills.

<span class="mw-page-title-main">Rhinoceros iguana</span> Species of iguana endemic to the Caribbean

The rhinoceros iguana is an endangered species of iguana that is endemic to the Caribbean island of Hispaniola and its surrounding islands. A large lizard, they vary in length from 60 to 136 centimetres, and skin colours range from a steely grey to a dark green and even brown. Their name derives from the bony-plated pseudo-horn or outgrowth which resembles the horn of a rhinoceros on the iguana's snout. It is known to coexist with the Ricord's iguana ; the two species are the only taxa of rock iguana to do so.

<i>Ctenosaura bakeri</i> Species of lizard

Ctenosaura bakeri, also known as the Utila spiny-tailed iguana, Baker's spinytail iguana, swamper or wishiwilly del suampo, is a critically endangered species of spinytail iguana endemic to the island of Utila, one of the Islas de la Bahía off the coast of Honduras in the Caribbean.

<span class="mw-page-title-main">Northern Bahamian rock iguana</span> Species of lizard

The northern Bahamian rock iguana is a species of lizard of the genus Cyclura that is found on Andros Island and the Exuma islands in the Bahamas. Its status on the IUCN Red List is vulnerable, with a wild population of less than 5,000 animals.

<i>Cyclura nubila</i> Species of reptile

The Cuban rock iguana, also known as the Cuban ground iguana or Cuban iguana, is a species of lizard of the iguana family. It is the second largest of the West Indian rock iguanas, one of the most endangered groups of lizards. A herbivorous species with a thick tail and spiked jowls, it is one of the largest lizards in the Caribbean.

<i>Cyclura ricordii</i> Species of iguana endemic to Hispaniola

Cyclura ricordii, also known as Ricord's ground iguana or Ricord's rock iguana, is an endangered species of medium-sized rock iguana, a large herbivorous lizard. It is endemic to the island of Hispaniola. It is known to coexist with the nominate subspecies of the rhinoceros iguana ; the two species are the only taxa of rock iguana to do so. The natural habitats of its three subpopulations are hot, dry, wooded savanna on limestone with access to soil and sandy flats in southern Hispaniola. It is threatened by predation by introduced predators and habitat loss, due to overgrazing and charcoal manufacture.

<i>Cyclura rileyi nuchalis</i> Subspecies of lizard

The Acklins ground iguana, also commonly known as the Watling Island iguana, is an endangered subspecies of lizard of the genus Cyclura it is one of three subspecific forms of Cyclura rileyi in the family Iguanidae.

<i>Cyclura rileyi</i> Species of lizard

Cyclura rileyi, commonly known as the Bahamian rock iguana or the San Salvador rock iguana, is a critically endangered species of lizard in the family Iguanidae. The species is native to three island groups in the Bahamas, and is in decline due to habitat encroachment by human development and predation by feral dogs and cats. There are three subspecies: the Acklins ground iguana, the White Cay iguana, and the nominotypical subspecies.

The Andros Island iguana or Andros iguana is an endangered subspecies of Northern Bahamian rock iguana of the genus Cyclura that is found on Andros Island on the western edge of Grand Bahama. Its status is Endangered, with a wild population of 3,500 animals, and it can be found on the IUCN Red List.

Cyclura cornuta onchiopsis, the Navassa Island iguana, was a subspecies of rhinoceros iguana that was found on the Caribbean island of Navassa.

<i>Cyclura nubila caymanensis</i> Subspecies of lizard

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<i>Cyclura cychlura inornata</i> Subspecies of lizard

Cyclura cychlura inornata, the Allen Cays rock iguana or Allen Cays iguana, is a subspecies of the northern Bahamian rock iguana that is found on Allen's Cay and adjacent islands in the Bahamas. Its status in the IUCN Red List is critically endangered. The population has been growing over the last century. Although it was considered extinct in 1916, there are as of 2018 at least 482 mature adult animals counted on two islands, Leaf Cay and U Cay, and a few hundred on at least five other nearby islands where they have recently spread to by unknown means, as well as many juveniles.

<i>Cyclura cychlura figginsi</i> Subspecies of lizard

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<i>Cyclura rileyi cristata</i> Subspecies of lizard

Cyclura rileyi cristata, the White Cay iguana or Sandy Cay rock iguana, is a critically endangered subspecies of lizard of the genus Cyclura native to a single cay in the Bahamas: White Cay located in the Southern Exumas.

<i>Cyclura</i> Genus of lizards

Cyclura is a genus of lizards in the family Iguanidae. Member species of this genus are commonly known as "cycluras" and only occur on islands in the West Indies. Rock iguanas have a high degree of endemism, with a single species or subspecies originating on an individual island.

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References

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  2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. Cyclura pinguis, The Reptile Database
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Mitchell, N. (1996). "Cyclura pinguis". IUCN Red List of Threatened Species . 1996: e.T6031A12343361. doi: 10.2305/IUCN.UK.1996.RLTS.T6031A12343361.en .
  5. 1 2 3 4 5 6 "Anegada Iguana". International Iguana Foundation - Anegada Iguana. International Iguana Foundation. October 21, 2006. Archived from the original on August 7, 2007. Retrieved September 8, 2007.
  6. 1 2 Malone, Catherine; Davis, Scott (2004), "Genetic Contributions to Caribbean Iguana Conservation", Iguanas: Biology and Conservation, University of California Press, pp. 52–57, ISBN   978-0-520-23854-1
  7. "Blue Iguana's Relatives". Blue Iguana Recovery Project. Archived from the original on August 12, 2007. Retrieved September 10, 2007.
  8. "Cyclura pinguis Barbour, 1917", Integrated Taxonomic Information System, 2001, retrieved October 8, 2007
  9. 1 2 Hollingsworth, Bradford D. (2004), "The Evolution of Iguanas: An Overview of Relationships and a Checklist of Species", Iguanas: Biology and Conservation, University of California Press, p. 38, ISBN   978-0-520-23854-1
  10. De Vosjoli, Phillipe; David Blair (1992), The Green Iguana Manual, Escondido, California: Advanced Vivarium Systems, ISBN   1-882770-18-8
  11. Martins, Emilia P.; Lacy, Kathryn (2004), "Behavior and Ecology of Rock Iguanas,I: Evidence for an Appeasement Display", Iguanas: Biology and Conservation, University of California Press, pp. 98–108, ISBN   978-0-520-23854-1
  12. 1 2 3 4 5 6 7 Hudson, Rick (2005), "Anegada Iguanas Released" (PDF), Iguana Specialist Group Newsletter, International Iguana Foundation, vol. 8, no. 1, pp. 2–4, archived from the original (PDF) on August 12, 2007, retrieved September 8, 2007
  13. Cogger, Harold; Zweifel, Richard (1992), Reptiles & Amphibians, Sydney, Australia: Weldon Owen, pp.  126, ISBN   0-8317-2786-1
  14. 1 2 Tickell, Oliver (1999-10-14), "UK 'allowing illicit trade in endangered species'", The (London) Independent
  15. Iverson, John; Smith, Geoffrey; Pieper, Lynne (2004), "Factors Affecting Long-Term Growth of the Allen Cays Rock Iguana in the Bahamas", Iguanas: Biology and Conservation, University of California Press, p. 200, ISBN   978-0-520-23854-1
  16. Alberts, Allison; Lemm, Jeffrey; Grant, Tandora; Jackintell, Lori (2004), "Testing the Utility of Headstarting as a Conservation Strategy for West Indian Iguanas", Iguanas: Biology and Conservation, University of California Press, p. 210, ISBN   978-0-520-23854-1