The Jamaican iguana (''Cyclura collei''), also known commonly as Colley's iguana, is a large

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of lizard in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Iguanidae The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the collared lizards (family Crotaph ...

. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Jamaica Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of His ...

. It is critically

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

, 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.

Etymology

The specific name, ''collei'', is in honor of someone named Colley.

John Edward Gray John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for ...

, who originally described this species in 1845, referred to it as "Colley's Iguana". Unfortunately, Gray did not further specify who Colley was. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . ("Colley's Iguana ''Cyclura collei'' ", pp. 56-57).

Anatomy and morphology

The Jamaican iguana is a large, heavy-bodied lizard, primarily green to salty blue in color with darker olive-green coloration on the shoulders. Three dark broad chevrons extend from the base of the neck to the tail on the animal's back, with dark olive-brown zigzag spots. The dorsal crest scales are somewhat brighter bluish-green than the body. The body surfaces are blotched with a yellowish blotched color breaking up into small groups of spots. Wild individuals, particularly nesting females, often appear deep reddish-brown in color after digging in the coarse ferralic soils of the Hellshire Hills region. The Jamaican iguana is the second-largest land animal native to Jamaica, with only the Jamaican boa weighing more. Males can grow to over and in length whereas females are slightly smaller, growing to in length. Males also possess large

femoral pore Femoral pores are a part of a holocrine secretory gland found on the inside of the thighs of certain lizards and amphisbaenians which releases pheromones to attract mates or mark territory. In certain species only the male has these pores and i ...

s on the undersides of their thighs, which are used to release

pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...

s. The pores of the female are smaller and they do not have a dorsal crest as high as the male's, making the animal somewhat

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

Distribution

According to

Sir Hans Sloane Sir Hans Sloane, 1st Baronet (16 April 1660 – 11 January 1753), was an Irish physician, naturalist, and collector, with a collection of 71,000 items which he bequeathed to the British nation, thus providing the foundation of the British Mu ...

, a physician and botanist who visited Jamaica in 1688, iguanas were once common throughout Jamaica. The Jamaican iguana declined dramatically during the second half of the 19th century, after the introduction of the

small Asian mongoose Small Asian mongoose is a common name applied to two mammals which were formerly considered to be a single species: * Javan mongoose *Small Indian mongoose The small Indian mongoose (''Urva auropunctata'') is a mongoose species native to Iraq an ...

as a form of rat and snake control, until it was believed to exist only on the Goat islands near the Hellshire hills. The Jamaican iguana was believed to be extinct in 1948. A dead adult specimen was found in 1970. The species was rediscovered in August 1990 when a live adult male iguana was chased into a hollow log by a dog of Edwin Duffus, a hog hunter in the Hellshire Hills. By the time he got there, the dog had injured the animal but that was the iguana that was taken to the Hope Zoo. A remnant population was discovered soon after. The Hellshire Hills area is the only area of Jamaica where this iguana is found. It is relegated to two dense populations that consist of scattered individuals. They were once prevalent in the island but are now only found in the dry, rocky, limestone forest areas of St. Catherine. Before it was rediscovered in 1990, the iguana was last seen alive on Goat Island off the coast of Jamaica in 1940.

Diet

Like all ''Cyclura'' species the Jamaican iguana is primarily

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...

, consuming leaves, flowers and fruits from over 100 different plant species. This diet is very rarely supplemented with insects and invertebrates such as snails. However, these could simply be eaten incidentally while it consumes the leaves the invertebrates live on.

Conservation

Endangered status

The Jamaican iguana was believed to be extinct dating to 1948. After its rediscovery in 1990, a study showed only that there were only 50 survivors of the "rarest lizard in the world". The IUCN lists it as a Critically Endangered Species.

Causes of decline

The single direct cause for the Jamaican iguana's decline can be attributed to the introduction of the

(''Urva auropunctata'') as a form of snake-control. The mongoose came to rely upon hatchling iguanas as a prime source of food, prompting the creation of the Headstart facility and a proposed program to eradicate the feral mongoose. The biggest current threat to the animals' existence is no longer from the spread of the mongoose, but from the charcoal industry. Charcoal burners rely on hardwood trees from the Hellshire Hills to make charcoal. As this is the primary refuge for the iguanas, the burners have been threatening the research teams who protect the iguanas.

Recovery efforts

A consortium of twelve zoos, also from within the USA donated and constructed a Headstart Facility at Hope Zoo, used for the rearing of eggs and hatchlings brought from the wild. From within the safety of this environment, they are reared until they are large enough to survive in the wild and predators such as the mongoose are no longer a threat, a process known as " headstarting". The Headstart facility also carries out health screening prior to the release of specimens. This health screening has been used to baseline the normal physiologic values of the species, identifying potential future problems due to parasites, diseases, etc. which might threaten the population. The US captive population doubled in size in August 2006 with the hatching of 22 Jamaican rock iguanas at the

Indianapolis Zoo The Indianapolis Zoo is a non-profit zoo, public aquarium, and botanical garden in Indianapolis, Indiana, United States. Incorporated in 1944, the Indianapolis Zoological Society established the first zoo at George Washington Park in 1964. The c ...

. This was the first successful captive breeding and hatching outside of Jamaica.

References

External links

Profile on Cyclura.com
*[https://web.archive.org/web/20121101035028/http://www.iguanafoundation.org/s2-25-Endangered-Jamaican-Iguanas-Hatched-at-the-Indianapolis-Zoo.aspx Endangered Jamaican Iguanas Hatched at the Indianapolis Zoo]
Saving the Jamaican Iguana:King of Reptiles(Jamaica)Jamaican Iguana making a comeback CNN Science
* {{DEFAULTSORT:Jamaican Iguana Cyclura Reptiles of Jamaica Critically endangered fauna of North America Endemic fauna of Jamaica iguana,Jamaican Reptiles described in 1845 Taxa named by John Edward Gray