The Lesser Antilles iguana We will speak more precisely of the Lesser Antilles iguana because it is an endemic animal of Guadeloupe which is on the verge of extinction. Its main predator is humans, who do not want them around their home and kill them. So the government put them on this island , “Reserve Petite Terre”, palace of biodiversity , in order to preserve the species and facilitate their reproduction. Schools regularly come to visit this island to work on the biodiversity it contains.
Iguanas are large, dragon-like American lizards. They indeed have a dorsal crest made up of large spines, which starts from the head to descend to the tail. There are more than 600 species of iguanas in the world. A species once widespread in most of the Lesser Antilles, this iguana is now one of the most endangered reptiles in the world and has already disappeared from many islands. Concerning the Guadeloupe, the last populations important are located on the island of Désirade (about 400 individuals) and especially on the Petite-Terre archipelago, which is home to nearly half of the world's population.
Gender recognition criteria Two criteria are almost systematically checked : * males have femoral pores of diameter much larger than females. At the base of the tail for a few centimeters it is quite easy to see the hemipenis in their sheaths, which seem to enlarge it. Males have a dorsal ridge with much taller spines, and have larger regular spines. The head is also in proportion to the body much larger in the male giving it a less slender appearance. *As a rule, females are rather green to green-brown. Males are generally gray to blackish-gray, with a whitening head. Their cheeks can take on a very pink color, especially during the breeding season, and more generally when testosterone levels rise. The color can be confusing, some females resembling males and some males, being able to be perfectly green adult size and with secondary sexual characteristics specific to males clearly less marked than in the majority of individuals.
Coloration Generally speaking, body color varies between individuals and over the course of an individual's life depending on age, sex, and social status. Bright apple green in juveniles and young to adult females, this color evolves to a dull green and darker to greenish gray in females, and a dark brown to blackish gray in males. Generally speaking, the head tends to turn white in both sexes.
Reproduction and egg-laying
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The timing of the reproductive cycle is particularly variable in tropical reptiles. Lesser Antillean Iguanas inhabiting more arid environments tend to exhibit a rather synchronous breeding season, with females laying a clutch usually from June to midAugust. In more humid environments, the breeding season is less synchronous, the laying can begin as early as February and continue until September. Females dig their nests in sandy or clay soils. The soil should be loose, well drained, and exposed most of the day to sunlight. The spawning areas are collective which means, that if the available space is too limited, for the number of adult females, excavations can be noted. The later females lay their eggs in the exact spot where an earlier female laid her eggs, and thus dig up the others' clutches, condemning them (the eggs are exposed to the elements, or even burst). Lesser Antilles iguanas can live up to 20 years and reach sexual maturity around 2-3 years for females and 3-5 years for males.
Its other predators : The black rat : Today present almost everywhere in the world, its introduction in Guadeloupe goes back to the beginning of the XVI th century. Arrived with the Spanish explorers, it easily adapted to the different natural environments present on the archipelago and began to proliferate. However, it is an omnivorous and arboreal species, very comfortable in trees. Its impact on avifauna (destruction of eggs and broods) is therefore very important. But the rat can also seek out iguana spawns to feed on the eggs and thus compromise reproductive success . * The common iguana : If its arrival in Guadeloupe is more recent than that of the rat, it dates from the 1960s, it is now the main threat for the Lesser Antilles iguana. It would come with sailors who used it as a food source.
Morphology The largest female captured to date measured 40.1cm in body for a weight of 2.6kg, also came from Dominique. The heaviest male weighed 3.7kg for a length of 42.8cm, and also came from Dominique. Average height and weight vary by island. On average, however, Lesser Antilles iguanas are much smaller in most areas than the examples above.
Threats: While the Lesser Antilles Iguana has been able to survive major climatic disturbances such as cyclones (although hurricanes Luis and Marylyn disrupted population dynamics), anthropogenic factors threaten it seriously. *The destruction of habitats: The most cultivated islands are those where the Lesser Antilles Iguana has disappeared or only survives in the form of small populations. Since colonization, its original biotope has been considerably altered due to agriculture (sugar cane plantations), logging, overgrazing by small ruminants, coastal urbanization and other coastal developments at low levels,tourist purposes. *Poaching: this is still a common practice in Guadeloupe. * Road traffic: gravid females migrating to coastal spawning sites (end of Lent) and young leaving the nest (beginning of wintering) are all the more cruelly victims. *The introduction of predatory species of young people (cats and dogs in particular). It is also subject to competition from the Green Iguana or Common Iguana, an anthropophilic and opportunistic species in full expansion. Finally, the hybridization of the Lesser Antilles Iguana with its congeneric the Green Iguana ,is also a determining factor in the rarefaction of the speci es. •
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Habitat and Nutrition The Lesser Antilles iguana ( Iguana delicatissima ) occupies a great diversity of habitats from sea level up to about 1000m elevation in Dominica. Its habitat includes xerophilic forests, the coast (eg Petite terre), mangroves, and more humid forests. This species seems to be mainly arboreal, although according to the populations, individuals are very frequently observed on the ground. However, this is perhaps only an artefact related to the type of intervention rather invasive, since it is about captures.
The favorite trees of Guadeloupe iguanas
What is the future of the Lesser Antilles Iguana? • The situation seems compromised in most of its original territories. Only two isolated populations reach several thousand individuals. So this is not very encouraging. • A national action plan (PNA) has however been developed with the objective of safeguarding the species. For example, for decades the Common Iguana has enjoyed the status of protected species in Guadeloupe. • It was therefore prohibited to destroy it, despite its invasive nature and its impact on the populations of West Indian iguanas .
Slideshow produced by Marie Elodie, Ruben, Djamélia, Jamila from Grand Camp School in Guadeloupe.
It is up to future generations to help the government improve knowledge to save this endemic species of iguana in Guadeloupe.