Tuesday 21 May
San Salvador iguana (Cyclura rileyi)
What’s the World’s Favourite Species?Find out here.
San Salvador iguana fact file
- Find out more
- Print factsheet
San Salvador iguana description
The San Salvador iguana is a strikingly handsome lizard, exhibiting an impressive crest of spiny scales down its back and a variable array of bright and beautiful colours (4). Varying between subspecies and indeed between individuals, the back can range from red, orange or yellow, to green, brown or grey, usually patterned by darker markings and fine vermiculations (4). The very brightest colours (red, orange or yellow) are normally only displayed by males, which are especially conspicuous at warmer body temperatures (4). Juveniles lack these bright colours, being solid brown or grey, usually with a slightly paler band in the middle of the back and faint longitudinal stripes (4). Body sizes of iguanas vary significantly from cay to cay, and seem to be positively correlated with the diversity of plant food available (1).
- Also known as
- Acklin’s ground iguana, San Salvador ground iguana, San Salvador rock iguana, Watling Island iguana, White Cay ground iguana.
- Cyclure des Bahamas, Iguane terrestre des Bahamas.
- Male snout-to-vent length: up to 395 mm (2)
- Female snout-to-vent length: up to 320 mm (2)
- up to 1.25 kg (2)
- Belonging to the same species.
- The temporary ex situ rearing of young in a favourable environment to permit maximmum early growth and/or protection from mortality in the wild, usually to reduce juvenile mortality due to predation.
- Mating with more than one partner in the same season.
- A pattern of fine, wavy, worm-like lines or streaks of colour.
- IUCN Red List (July, 2006)
- Cyclura.com: Blair, D.W. – West Indian Iguanas of the Genus Cyclura, Their Current Status in the Wild, Conservation Priorities, and Efforts to Breed them in Captivity (March, 2006)
- CITES (January, 2006)
- Alberts, A. (1999) West Indian Iguanas: Status Survey and Conservation Action Plan. IUCN/SSC West Indian Iguana Specialist Group, Gland, Switzerland and Cambridge. Available at:
- ARDASTRA: Gardens, Zoo and Conservation Centre (March, 2006)
- Hayes, W.K. and Carter, R.L. (2005) Biology and conservation of Cyclura rileyi, an endangered Bahamian rock iguana. In: McGrath, T. and Buckner, S. (Eds) Proceedings of the 10th Symposium on the Natural History of the Bahamas. Gerace Research Center, San Salvador Island, Bahamas.
- International Iguana Foundation (March, 2006)
- San Salvador’s Living Jewels Foundation (March, 2006)
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
San Salvador iguana biology
The mating season of this rock iguana begins in May and continues into June, followed by nest digging from the end of June into July, and hatchlings emerge from nest-burrows in September or October (6). Both males and females have been observed mating with multiple partners, and a polygamous mating system is thought likely, although repeat matings with the same partner are also frequently observed (6). As a result of competition for access to females, some males may utilise forced-copulation and mate-guarding (6). Clutch size correlates to female body size, both of which are relatively small compared to other iguanas, and can vary between anything from two to ten eggs, depending on the subspecies and location (6). Nest defence by females appears to vary with nesting density (6), but males seem to be territorial throughout the year (4). Indeed, male Acklin’s iguanas (C. r. nuchalis) have been observed chasing other males out of defended areas, and engaging in ‘jousting matches’ involving open-mouthed territorial displays, and individuals often bear bite-mark-like scars (4).
This iguana primarily feeds on plant material of several species, but birds, conspecific hatchlings, the legs of dead land crab, a grasshopper, a hermit crab and insect material have also been recorded in the diet (6).Top
San Salvador iguana range
The nominate subspecies, C. r. rileyi, was once found throughout the main island of San Salvador, but is now largely restricted to two cays (Guana and Pigeon) within the Great Lake, and four tiny offshore cays (Goulding, Green, Low, Manhead) (5) (6). In 2005, 10 individuals were also moved from Green Cay to Cut Cay off San Salvador Island, creating a new population (7). The White Cay iguana (C. r. cristata) is found only on a single island, White (Sandy) Cay, in the southern Exuma Islands of The Bahamas (1). Natural populations of Acklin’s iguana (C. r. nuchalis) occur only on Fish Cay and North Cay in the Acklins Bight, Bahamas (1), but an introduced population also exists on a single island in the Exumas Land and Sea Park (6).Top
San Salvador iguana habitat
A wide range of habitat is used, including coastal rock and limestone rocky outcrops, sand dunes, coastal coppice and blacklands coppice vegetation, and mangrove vegetation communities (1) (5). Like other rock iguanas (Cyclura spp.), San Salvador iguanas are thought to require loose soil or sandy areas for nest construction (1).Top
San Salvador iguana status
Classified as Endangered (EN) on the IUCN Red List 2006 (1) and listed on Appendix I of CITES (3). Subspecies: the San Salvador iguana or San Salvador rock iguana (C. r. rileyi) and the White Cay iguana (C. r. cristata) are classified as Critically Endangered (CR), and Acklin’s iguana or San Salvador rock iguana (C. r. nuchalis) is classified as Endangered (EN) on the IUCN Red List 2006 (1).Top
San Salvador iguana threats
Cyclura rileyi is amongst the most threatened of the West Indian rock iguanas, with two of its three recognised subspecies being listed as critically endangered by the IUCN, and the third as endangered (6). One of the most devastating impacts has been the large-scale habitat destruction by European and American colonialists, who cleared forests for conversion to agriculture, and introduced many non-native plants and animals (6). The San Salvador iguana now has a relatively remote distribution away from most human settlements, but a large and varied range of threats nevertheless continue to make their prospects of long-term survival tenuous (4) (8).
The species is vulnerable to introduced predators and feral animals such as cats, dogs and rats, with rats recently discovered on Guana, Low, High, and Pigeon Cays, and juvenile iguanas noticeably scarce on Guana and Low Cays (4) (8). Habitat degradation is also a concern, with vegetation being damaged by catastrophic storms and hurricanes in the areas, as well as by the larvae of an introduced moth (Cactoblastis cactorum), which are devastating the prickly-pear cacti (Opuntia stricta), an important food source for iguanas on several cays (4) (8). Sadly, there are no known means of controlling the moth (4) (8). A mysterious ‘die-off’ also occurred on Guana Cay in spring 1994, possibly as the result of disease (4). However, it has also been suggested that mosquito control chemicals, which had recently been implemented to aid a growing tourism industry, could have been the culprit (4). Disease could potentially be catastrophic to many of the subpopulations due to their small and isolated nature (8). Small populations are also likely to suffer from the negative effects of inbreeding, diminishing their viability (4). A further threat to most, if not all, populations, is rising sea levels, which threaten to swamp much of the iguana’s existing habitat in the future (6).
An additional threat to the small population of White Cay iguanas (C. r. cristata) is the invasion of Australian pine trees (Casuarina), which have begun to dominate the vegetation on White Cay, attracting numerous birds of prey (falcons) during winter and migration (6). There is also evidence of illegal smuggling of the White Cay iguana (C. r. cristata), which probably poses the greatest threat to this subspecies, together with the possibility of introduced animals (4). Indeed, a raccoon discovered on White Cay apparently killed a significant proportion of the small iguana population, particularly juveniles and females (4), before it was removed in 1997 (6).
Fortunately, the Acklin’s iguana (C. r. nuchalis) populations seems to be fairly stable, although introduced hutia (Geocapromys ingrahami) on a neighbouring cay may be affecting the vegetation available to the subspecies, and the potential for illegal poaching remains a threat (4).Top
San Salvador iguana conservation
Since a number of surrounding cays, as well as the mainland of San Salvador, have very similar habitat to that currently used by the species, reintroductions to parts of the iguana’s former range are a viable and important focus of conservation efforts (4). An introduced population of Acklin’s iguanas (C. r. nuchalis) currently thrives on an island within the Exumas Land and Sea Park (6), and a successful translocation of five adult pairs of C. r. rileyi from Green Cay to Cut Cay took place in February 2005, funded by a 2004 grant from the International Iguana Foundation (7). Candidate cays for further reintroductions (and source of animals) include Barn Cay (from Guana Cay), Cato Cay (from Green Cay), and High Cay (from Low Cay). Corrective actions may first be required to render each cay suitable for reintroduction (e.g., removal of feral rats), and reintroduction of iguanas on the mainland should be undertaken only if large areas are protected, particularly from the feral dogs and cats that are already numerous in local areas (4).
There have also been efforts to remove invasive species and restore nesting habitat on a number of cays (6). Black rats were eradicated in 1998 on White Cay, and in 2000 on Low Cay, and virtually all of the extensive Casuarina on White Cay was cut down in 2005 (6). Two cays have also been identified as potential sites for the establishment of a second wild population of the critically endangered White Cay iguana (C. r. cristata) subspecies (4).
Ardastra Gardens in Nassau (New Providence Island, Bahamas) currently holds two juveniles in captivity, and it has been argued that the development of a captive-breeding programme here could help benefit reintroduction attempts and the preservation of genetic diversity of small populations (4). It has also been suggested that captive head-starting programmes, which have been highly successful for other West Indian iguanas, could help survival rates of this rare species (6). Additionally, a public relations campaign will be critical to the conservation of this iguana, important both in raising awareness and concern among island residents for their threatened iguana, and in promoting the need for complete protection of the cays on which these beautifully colourful yet dangerously threatened iguanas live (4).Top
Find out more
For more information on the San Salvador iguana see:
IUCN Red List:
Alberts, A. (1999) West Indian Iguanas: Status Survey and Conservation Action Plan. IUCN/SSC West Indian Iguana Specialist Group, Gland, Switzerland and Cambridge. Available at:
Authenticated (31/07/2006) by Dr. William Hayes, Professor of Biology, Loma Linda University.
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.