Cyclura is a genus of lizards from the family Iguanidae. Members of this genus are known as "cyclurids" or more commonly as rock iguanas and only occur on islands in the West Indies.^[1] Rock iguanas have a high degree of endemism, with a single species or subspecies restricted to individual islands.^[2][3]

Taxonomy

The generic name (Cyclura) is derived from the Ancient Greek cyclos (??????) meaning "circular" and ourá (????) meaning "tail", after the thick-ringed tail characteristic of all Cyclura.^[4]

Currently there are nine described species and eight subspecies identified in this genus.^{[2][5][6][7][8][9]}

• Turks and Caicos Rock Iguana, Cyclura carinata^[9]
  • Bartsch's Iguana, Cyclura carinata bartschi^[9]
• Jamaican Iguana, Cyclura collei^[9]
• Rhinoceros Iguana, Cyclura cornuta^[9]
  • Navassa Island Iguana (believed to be extinct), Cyclura cornuta onchiopsis^[9]
  • Mona Ground Iguana, Cyclura cornuta stejnegeri^[9]
• Northern Bahamian Rock Iguana, Cyclura cychlura^[9]
  • Andros Island Iguana, Cyclura cychlura cychlura^[9]
  • Exuma Island Iguana, Cyclura cychlura figginsi^[9]
  • Allen Cays Iguana, Cyclura cychlura inornata^[9]
• Grand Cayman Blue Iguana, Cyclura lewisi^[10]
• Cuban Iguana, Cyclura nubila^[9]
  • Lesser Caymans Iguana, Cyclura nubila caymanensis^[9]
• Anegada Ground Iguana, Cyclura pinguis^[9]
• Ricord's Iguana, Cyclura ricordi^[9]
• San Salvador Iguana, Cyclura rileyi rileyi^[9]
  • White Cay Iguana, Cyclura rileyi cristata^[9]
  • Acklins Iguana, Cyclura rileyi nuchalis^[9]

Habitat

Rock iguanas of the genus Cyclura most often inhabit subtropical areas of West Indian dry forest biomes characterized by eroded limestone and sparse vegetation ranging from only moderately dry acacia forest to much drier mesquite and cactus habitats.^[11] These are nonvolcanic islands made up of heavily eroded limestone which form natural caves that they use as retreats.^[11]

Diet and longevity

All Cyclura species are primarily herbivorous, consuming leaves, flowers, berries, and fruits from different plant species.^[3] A study in 2000 by Dr Allison Alberts of the San Diego Zoo revealed that seeds passing through the digestive tracts of Cycluras germinate more rapidly than those that do not.^[12][13] These seeds in the fruits consumed by cycluras have an adaptive advantage by sprouting before the end of very short rainy seasons.^[13] The cycluras are also an important means of distributing these seeds to new areas (particularly if females migrate to nesting sites) and, as the largest native herbivores of many island ecosystems, they are essential for maintaining the balance between climate and vegetation.^[13] This diet is very rarely supplemented with insect larvae, crabs, slugs, dead birds, and fungi; individual animals do appear to be opportunistic carnivores.^[3]

The record for the longest lived captive-born Cyclura is held by a Lesser Caymans iguana, which lived for 33 years in captivity.^[14]

A Blue iguana captured on Grand Cayman in 1950 by naturalist Ira Thompson was imported to the United States in 1985 by Ramon Noegel and loaned to the Gladys Porter Zoo in Brownsville, Texas in 1997.^[15] The lizard was named Godzilla by the zoo staff and was kept until his death in 2004.^[15] Thompson estimated the iguana to be 15 years of age at the time of its capture.^[15] This lizard may have been the word's longest-living recorded lizard at 69 years of age, having spent 54 years in captivity.^[15]

Reproduction

Males of each species within the genus Cyclura are larger than females and have more prominent dorsal crests in addition to femoral pores on their thighs, which are used to release pheromones, females lack these pores and have shorter crests than the males making the animals somewhat sexually dimorphic.^[16][17]

Although the particulars vary slightly among species and subspecies the lizards of the genus Cyclura, reach sexual maturity at three to seven years of age.^[16] Females become sexually mature at two to five years of age. Males can be highly territorial with the notable exception of the Exuma Island Iguana.^[16] Mating takes place at the beginning of or just prior to the first rainy season of the year (May to June) and lasts for two to three weeks.^[16] Females lay from 2 to 34 eggs, with an average clutch size of 17 within 40 days.^[16] Females of most species guard their nests for several days after laying their eggs, and incubation lasts approximately 85 days.^[16] It has been noted that Cyclura eggs are among the largest lizard eggs produced in the world.^[16]

Conservation status

Every species and subspecies within the genus Cyclura is endangered.^[13][18] Nine of these taxa are Critically Endangered, meaning there are fewer than 250 of each species or subspecies left in wild populations and in danger of Extinction, four taxa are endangered and three species have been identified as Vulnerable, one species is believed to be extinct in the wild.^[2] These iguanas are vital to their native ecosystems as seed dispersers for native vegetation and their loss may have serious consequences.^[13] In addition to small numbers typical of endemic island-dwelling animals, wild populations of these lizards are directly and indirectly impacted by land development, overgrazing by domestic and feral livestock and predation by humans and feral mammals such as hogs, cats, rats, dogs, and mongooses.^[2]

Recovery programs

In 1990, the American Zoo and Aquarium Association (AZA) designated the genus Cyclura as their highest priority.^[18] Their first project was a captive breeding program for the Grand Cayman iguana, which at the time was the most critically endangered of all the species of Cyclura.^[18]

The Indianapolis Zoo is involved in research and conservation of all 16 taxa of West Indian iguanas.^[18] This includes collaborative work on establishing baseline biological values in captive and wild iguanas, and scientific investigation, conservation efforts, field research and captive breeding programs.^[18] The Indianapolis Zoo has been involved in the Dominican Republic for almost ten years and will continue its research and conservation efforts with the Ricord's iguana.^[19]

Grand Cayman Blue Iguana, Cyclura lewisi

The project's goals are:

• to work with the Ricord?s Iguana Recovery Group to implement the ISG?s Species Recovery Plan.
• to conduct a census of iguanas on Isla Cabritos, Dominican Republic.^[19]
• to determine vitamin D status of captive West Indian iguanas at the Zoo before and after exposure to sunlight.^[18]
• to continue to develop long-term captive breeding programs for Grand Cayman Island Blue iguanas and Jamaican iguanas at the Indianapolis Zoo.^[20]
• to work in partnership with ZOODOM (the national zoo of the Dominican Republic) to develop a long-term captive breeding and husbandry program for Ricord?s iguanas.^[19]
• to develop an education program for West Indian Iguanas and their habitats.^[18]

References

External links

• All about Cycluras
• Father Sanchez's Website of West Indian Natural History
• Blue Iguana Recovery Program (B.I.R.P.)
• the International Reptile Conservation Foundation
• the Durrell Wildlife Conservation Trust
• Reptile Stamps - Stamps featuring pictures of West Indian iguanas

de:Wirtelschwanzleguane es:Cyclura fr:Cyclura ko:?????? pt:Cyclura

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