Jamaican iguana
Encyclopedia
The Jamaican Iguana is a large species of lizard
of the genus Cyclura
endemic to Jamaica
. It is the largest native land animal
in the country, and is critically endangered, being thought extinct since 1948. Once found throughout Jamaica and on Goat island
, it is now confined to the forests of the Hellshire hills.
name (Cyclura
) is derived from the Ancient Greek
cyclos (κύκλος) meaning "circular" and ourá (οὐρά) meaning "tail", after the thick-ringed tail characteristic of all Cyclura. Its specific
name Collei is Latin for the word "hill" and refers to the regions in which it was once found in Jamaica.
Male Jamaican iguanas grow to approximately 428mm in length whereas females are slightly smaller, growing to 378mm in length. Males also possess large femoral pore
s on the undersides of their thighs, which are used to release pheromone
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
.
, 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 Indian mongoose 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 specemein was found in 1970, and the species was rediscovered in 1990 when a live iguana was captured by a hog hunter in the Hellshire hills and 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.
(herpestes auropunctatus) 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.
The US captive population doubled in size in August 2006 with the hatching of 22 Jamaican rock iguanas at the Indianapolis Zoo
. This was the first successful captive breeding and hatching outside of Jamaica.
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
of the genus Cyclura
Cyclura
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...
endemic to Jamaica
Jamaica
Jamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
. It is the largest native land animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
in the country, and is critically endangered, being thought extinct since 1948. Once found throughout Jamaica and on Goat island
Goat Island, Trinidad and Tobago
Goat Island is an island in the Republic of Trinidad and Tobago. It is located off the coast of Speyside, between Tobago and Little Tobago.Some sources say Goat Island is the former home and retreat of Ian Fleming, the author and creator of the James Bond series. An article which appeared in...
, it is now confined to the forests of the Hellshire hills.
Taxonomy
The Jamaican iguana's genericGenus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name (Cyclura
Cyclura
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...
) is derived from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
cyclos (κύκλος) meaning "circular" and ourá (οὐρά) meaning "tail", after the thick-ringed tail characteristic of all Cyclura. Its specific
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
name Collei is Latin for the word "hill" and refers to the regions in which it was once found in Jamaica.
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.Male Jamaican iguanas grow to approximately 428mm in length whereas females are slightly smaller, growing to 378mm in length. Males also possess large femoral pore
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 in other species, both sexes have them, with the males...
s on the undersides of their thighs, which are used to release pheromone
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 outside the body of the secreting individual to impact the behavior of the receiving individual...
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
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
.
Distribution
According to Sir Hans SloaneHans Sloane
Sir Hans Sloane, 1st Baronet, PRS was an Ulster-Scot physician and collector, notable for bequeathing his collection to the British nation which became the foundation of the British Museum...
, 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 Indian mongoose 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 specemein was found in 1970, and the species was rediscovered in 1990 when a live iguana was captured by a hog hunter in the Hellshire hills and 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
Saint Catherine Parish, Jamaica
St Catherine is a parish located in the south east of Jamaica. It is located in the county of Middlesex, and is one of the island's largest and most economically valued parish because of its many resources. It includes the first capital of Jamaica, Spanish Town, originally known as San Jago de la...
. 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, 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 invetebrates live on.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 Indian mongooseMongoose
Mongoose are a family of 33 living species of small carnivorans from southern Eurasia and mainland Africa. Four additional species from Madagascar in the subfamily Galidiinae, which were previously classified in this family, are also referred to as "mongooses" or "mongoose-like"...
(herpestes auropunctatus) 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
Indianapolis Zoo
The Indianapolis Zoo in Indianapolis, Indiana, United States, first opened to the public in 1964. Its current home in White River State Park was opened in 1988 with a size of . The zoo hosts more than a million visitors each year and plays a role in worldwide conservation and research, including...
. This was the first successful captive breeding and hatching outside of Jamaica.