Lifespan, longevity, and ageing
provided by AnAge articles
Maximum longevity: 23.4 years (captivity)
- license
- cc-by-3.0
- copyright
- Joao Pedro de Magalhaes
- editor
- de Magalhaes, J. P.
Biology
provided by Arkive
Foraging during the day both in trees and on the ground, this species primarily feeds on flowers, fruits, young buds and leaves. Allen's Cay iguana is also reported to be opportunistically carnivorous, and tourists regularly feed them everything from table scraps to fresh produce. Unusually, a report also exists that the Exuma Island iguana is coprophagous, actively foraging for the faeces of the zenaida dove, Zenaida leucocephala, and the white-crowned pigeon, Columba leucocephala (2).
The Allen's Cay iguana has been seen mating in mid-May, followed by nesting from mid to late June, whereas that Andros iguana mates in April, nesting in May and June (4). Cyclura species usually dig a subterranean nest chamber in sand or soil. However, Andros iguanas predominantly use termite mounds, providing a dry habitat and a relatively high and constant temperature for egg incubation (4). Although initial attempts by Allen's Cay iguanas at digging nest burrows are often abandoned, females defend the burrow site during the entire time of construction, and most continue that defence for at least three to four weeks after nest completion between mid-June and mid-July (5). Conversely, while female Exuma Island iguanas have also been observed actively defending an incomplete nest, they do not appear to protect the nest site after their eggs have been laid (2).
Although not all females will reproduce each season, the largest Allen's Cay iguana females usually nest annually. Clutch size ranges between one and ten eggs, with larger, older females typically producing larger clutches. Allen's Cay iguana hatchlings apparently emerge in late September and early October, after about 80 to 85 days incubation (5). Clutch sizes for the Andros iguana range from 4 to 19 eggs. After approximately 75 days incubation, hatchling Andros iguanas emerge in August and September. Female sexual maturity is not attained until approximately 12 years of age in the Allen's Cay iguana and 8 years of age in the Andros iguana, but this very slow rate of development is offset by a long lifespan of up to 40 years (4) (6).
Conservation
provided by Arkive
Cyclura cychlura is included in CITES Appendix I, prohibiting international trade in the species, and like all Bahamian rock iguanas, is protected at the national level under the Wild Animals Protection Act of 1968 (1). Nevertheless, law enforcement is difficult for Allen's Cay iguanas without a warden present within its range. Although the warden of the nearby Exumas Land and Sea Park can potentially respond to reports of poaching, this is not always practical. Signs have been erected on the islands explaining the endangered status of these lizards. Since a small non-breeding population lives on Allen's Cay without suitable sandy areas for nesting, one suggested conservation measure is to dredge sand to upland areas, which could potentially double the available breeding habitat for this subspecies. A few captive individuals are kept at the Ardastra Zoo and Nature Centre Different on Abaco, and captive breeding is a key objective of the centre for the future (2).
For the Andros Island iguana, a new area on the north of the island was given protected status in 2003, conferring a degree of safety. However, few iguanas inhabit this area, which is really only protected on paper, with no actual protection measures existing on the ground. Captive populations exist in Ardastra Gardens, Nassau, in the Bahamas, and Los Angeles Zoo in the U.S. (2).
Ongoing research is documenting the potential threats facing the Exuma Island Iguana unique to each cay it inhabits, information that is designed to help the Bahamian government with setting appropriate conservation policies. Additionally, the suitable habitat on cays not currently supporting iguanas is being investigated for possible translocation programmes in the future. Signs are also erected on Gualin Cay notifying the public of the protected status of the iguanas. Protected areas in the Exumas include Pasture and Alligator Cays, Exuma Cays Land and Sea Park (2).
Description
provided by Arkive
Like other West Indian rock iguanas (Cyclura spp.), the northern Bahamian rock iguana is a large and robust 'dinosaur-like' lizard with an impressive crest of spiny scales running down its back and a variable array of bright and beautiful colours, particularly between the three subspecies. The Andros Island iguana is dark grey to black, with yellowish tinged scales on the legs, dorsal crest, and particularly the head. With maturity, however, this yellow slowly changes to a warm orange-red, especially in large males. The Exuma Island iguana is generally regarded as the smallest of the three subspecies, although size may vary between populations as colouration does. Adults from Bitter Guana and Gaulin Cays are a dull grey-black interspersed with pale grey spots. The crest scales are either white or pale red, while scales on the head are black, tinged with orange on the snout. Adults from Guana Cay are dull black with a white throat and belly, either grey, red-tinged or scarlet dorsal crest, and light blue head and face. Allen's Cay iguana is grey-black with cream, pink or orange mottling (2).
Habitat
provided by Arkive
Preferred habitats include tropical dry forest, pine barrens, coastal coppice, mangrove and beach strand vegetation areas (1), while limestone crevices and burrows in the sand provide suitable retreats at night and in adverse weather conditions (2).
Range
provided by Arkive
This iguana is native to Andros and the Exuma Islands of the Bahamas (1). As its common name suggests, the Andros Island iguana inhabits Andros Island, the largest of the Bahamian Islands, while the Exuma Island iguana occurs on seven small cays scattered throughout the central and southern Exuma Island chain. Allen's Cay iguana is also found in the Exuma Island chain, where only two breeding populations are known in the north, on leaf Cay (four hectares) and U Cay (also known as Southwest Allen's Cay; three hectares). A handful of adults also live on Allen's Cay (seven hectares), but there has as yet been no evidence of breeding there (2).
Status
provided by Arkive
Classified as Vulnerable (VU) on the IUCN Red List 2007 (1) and listed on Appendix I of CITES (3). Subspecies: Cyclura cychlura cychlura (Andros iguana, Andros Island iguana or Andros Island rock iguana) is classified as Endangered (EN); C. c. inornata (Allen's Cay iguana or Allen's Cay rock iguana) is classified as Endangered (EN), and C. c. figginsi (the Exuma Island iguana or Exuma Island rock iguana) is classified as Critically Endangered (CR) on the IUCN Red List 2007 (1). All subspecies are listed on Appendix I of CITES (3).
Threats
provided by Arkive
The Andros population is threatened by habitat loss as a result of island-wide logging, and construction of homes and roads (1). Additionally, feral pigs, which have proliferated and expanded their range, are known to root out eggs from iguana nests and pose a very real threat. Predation by feral and domestic dogs also threatens both juvenile and adult animals. Subsistence hunting is thought to continue, with many local residents apparently unaware of the protected status of the Andros Island iguanas (2).
The main threats to the subspecies in the Exumas include the growing tourism industry there and the potential damage caused by increased human traffic. For example, a large-scale fire occurred in 2004 on an iguana-inhabited island that had recently become a tourist destination, purportedly the result of a tourist cigarette. Many of the islands are private, and are rapidly being bought for development. Illegal hunting is a serious concern, both for food and for the pet trade, and feral animals also pose a significant threat (1). Additionally, hurricanes in the area could endanger certain populations (2).
Northern Bahamian rock iguana
provided by wikipedia EN
The northern Bahamian rock iguana (Cyclura cychlura) 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.[1]
Taxonomy
It was first described as a new species, Iguana cychlura, by Georges Cuvier in 1829.[1]
Mitochondrial DNA analysis by biologist Catherine Malone found its closest relatives to be Cyclura nubila on Cuba, and C. lewisi on Grand Cayman. According to her C. lewisi, C. nubila and C. cychlura had diverged almost as much as each other, although she only used a single locus and a very small sample set of each species.[3] According to a 2005 article in the magazine New Scientist C. lewisi may have diverged from C. nubila some 3 million years ago.[4]
There are three recognised subspecies of the northern Bahamian rock iguana: the Andros Island iguana (C. cychlura cychlura), Allen's Cay iguana (C. c. inornata) and the Exuma Island iguana (C. c. figginsi).[1][5] Although Malone's research found C. c. cychlura as being phylogenetically distinct from C. c. figginisi and C. c. inornata, she found these two populations were indistinct genetically and should likely be synonymised.[3]
Description
This species, like other species of Cyclura, is sexually dimorphic; males are larger than females, and have more prominent femoral pores on their thighs which are used to release pheromones.[6][7]
Distribution
This species only occurs in the southwestern Bahamas. 18,000 years ago during the last ice age and the sea level was much lower, many of the islands of the Bahamas were connected to each other and this species probably existed in an unbroken population,[3] the relict populations now inhabit Andros Island and the Exuma islands.[1]
Ecology (Habitat)
It lives in tropical dry forest, pine barrens, coastal coppice, mangrove and beach strand habitats. These are found on low islands built from karst limestone plateaus. Like all Cyclura species, the northern Bahamian rock iguana is primarily herbivorous. It is ground-dwelling, although juveniles often climb into branches in the morning to bask and feed.[1]
Conservation
Status
In 2004 the IUCN assessed the species as a whole to be "vulnerable", although each of the three subspecies were assessed as endangered. The current global population of all three subspecies was estimated at less than 5,000 members and was thought to be declining. The population had decreased by at least 50% over the last 60 years.[1]
Causes of decline
In 2004 the IUCN listed the main threats to this lizard depended on the islands where the different subspecies came from; with the Andros Island population to be threatened by logging, infrastructure development, feral animals and fires set for agricultural or crab-hunting reasons. The populations from the Exumas were imperilled due to feral animals (goats), fires caused by tourists, and rapid private land acquisition (primarily for tourism purposes). Development, fire and feral animals had caused a reduction in area of suitable habitat of at least 20% over the previous 30 years. Feral animals which pose a threat to the iguanas are cats, dogs, hogs and goats.[1] Dogs prey upon juvenile and adult iguanas, hogs eat their eggs.[8] All populations were still occasionally being hunted for meat or for the pet trade according to the IUCN in 2004.[1] An 2002 article in the Miami Herald quoted an officer of the Bahamas' Department of Agriculture who stated iguanas were still sometimes hunted and eaten, albeit rarely.[8]
References
-
^ a b c d e f g h i j Knapp, C.R.; Iverson, J.B.; Buckner, S. (2004). "Cyclura cychlura". IUCN Red List of Threatened Species. 2004: e.T6035A12356382. doi:10.2305/IUCN.UK.2004.RLTS.T6035A12356382.en. Retrieved 16 November 2021.
-
^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
-
^ a b c Malone, Catherine L.; Wheeler, Tana; Taylor, Jeremy F.; Davis, Scott K. (November 2000). "Phylogeography of the Caribbean Rock Iguana (Cyclura): Implications for Conservation and Insights on the Biogeographic History of the West Indies". Molecular Phylogenetics and Evolution. 17 (2): 269–279. doi:10.1006/mpev.2000.0836. PMID 11083940. Retrieved 19 February 2020.
-
^ Kenyon, Georgina (14 September 2005). "Pulling the blue iguana from the brink". New Scientist. No. 2517. London: Simone Coless. pp. 42–43. Retrieved 23 February 2020.
-
^ 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: 36–37. ISBN 978-0-520-23854-1.
-
^ De Vosjoli, Phillipe; David Blair (1992). The Green Iguana Manual. Escondido, California: Advanced Vivarium Systems. ISBN 1-882770-18-8.
-
^ 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: 98–108. ISBN 978-0-520-23854-1.
-
^ a b Morgan, Curtis (July 7, 2002). "In Bahamas Some Indulge Taste For Dwindling Iguana". Miami Herald. Archived from the original on June 19, 2008. Retrieved 2007-10-14.
- license
- cc-by-sa-3.0
- copyright
- Wikipedia authors and editors
Northern Bahamian rock iguana: Brief Summary
provided by wikipedia EN
The northern Bahamian rock iguana (Cyclura cychlura) 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.
- license
- cc-by-sa-3.0
- copyright
- Wikipedia authors and editors
Data related to Cyclura cychlura at Wikispecies
Media related to Cyclura cychlura at Wikimedia Commons
