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How to grow your Lesser Antillean Iguana: Scientists hold hope for hatchlings

The Lesser Antillean Iguana isn’t the world’s next reptilian movie star. However, as it is listed as an endangered species on the International Union for Conservation of Nature’s Red List (IUCN), it may be reaching news headlines for a more concerning reason – extinction.

 

How to grow your Lesser Antillean Iguana: Scientists hold hope for hatchlings

Alayna Hansen

 
From Godzilla to Jurassic Park, fictional attempts to breed lizard species have certainly produced some surprising results. Whether it was a giant, mutated reptilian monster terrorising the city or a stampede of resurrected dinosaurs, the initial catalyst for scientists remained in intensive field research and an aspiration to achieve greater feats of science than ever before. In reality, the excitement is no different to that experienced by the herpetology team at Durrell Wildlife Conservation Trust in Jersey, who have succeeded in breeding 11 Lesser Antillean Iguanas (Iguana delicatissima) as part of their captive breeding program.
 
Durrell’s Head of Herpetology Matt Goetz says the new hatchlings are the offspring of an adult pair that hatched in 2011, marking a milestone as the first breeding success of a second generation in captivity.
 
“This proves to us that we have reared the previous offspring in the best possible conditions. The expertise of our keepers and the food plants grown especially for them at Durrell’s organic farm has undoubtedly contributed to this success,” he said.
 

Saving Animals From Extinction

 
Durrell’s conservation strategies span over 50 projects in 18 different countries, focusing on archipelago regions, threatened animals that are under immense pressure due to human intervention, prevalent impacts of natural predators and intrusive pest species. Guiding local conservationists to research, monitor and protect native wildlife, their determination and expertise are ensuring their mission of “saving animals from extinction” is consistent and effective.
 
Goetz’s team remain the only zoological institution that has managed to breed the critically endangered species since 1997. One single offspring in this first attempt was followed by eight juveniles three years later, yet despite their determination to produce fertilised eggs, between 2000 and 2010 all clutches were confirmed sterile. It wasn’t until September 2011 that a female was paired with an introduced male, producing two young hatchlings after an incubation period of 75 days. Success!
 
Although five years passed before the next effective mating, Goetz holds hope for the future of the current brood.
 
“The hatching of eleven youngsters is very encouraging. The youngsters will be sent to zoos around Europe, which we hope will promote and support the urgent conservation work for this species in the Caribbean,” he said.
 

Not the Next Blockbuster Star

 
Endemic to the Lesser Antilles archipelago (hence their name), offspring are bright green with white flashes from the jaw to the shoulder and 3 vertical stripes on the sides of their body for the duration of their adolescence. Females also maintain their distinctive base colouring with a slightly paler head and brown tail, while males develop slate grey scales and the appearance of a pale-blue head and pink jowls when reproductively active. Forming a dominance hierarchy, the herbivores live as large communities in rainforests, woodlands and mangroves spanning the mountainous region; favouring dry leaf-litter and thick vegetation as ideal protection from predators.
 
The Lesser Antillean Iguana isn’t the world’s next reptilian movie star. However, as it is listed as an endangered species on the International Union for Conservation of Nature’s Red List (IUCN), it may be reaching news headlines for a more concerning reason – extinction.
 

The Lesser Antillean Iguana

 
An arboreal lizard, the species was once renowned throughout the local islands. According to IUCN research based on historic range data, it is estimated that the overall population has experienced major declines of more than 70 percent since first European contact, resulting in a restricted geographical region of 3000km2. Now, limited numbers can only be found on northern islands such as Martinique, Guadeloupe, Statia, Anguilla, St. Barths and Dominica; and are even still beset by a number of human and natural threats to survival.
 
Particularly on Guadeloupe, Martinique and St. Lucia; deforestation of mangroves and sugar cane fields for local timber production and other agricultural practices has resulted in substantial loss of habitat and food sources. Similarly, slash and burn farming on vertical terrain, that is susceptible to erosion, can cause chemical run-off from pesticides and lead to poisoning of lower habitat areas.
 
Surpassing agriculture as the chief industry, tourism growth has also escalated coastal development and reduced inhabitable areas through the construction of tropical resorts, entertainment areas and roads to popularise the holiday destination. In consequence, the increase of road traffic has killed numerous pregnant females migrating during the dry season to coastal nesting sites, as well as new hatchlings emerging late in the wet season.
The prevalence of hunting the Lesser Antillean Iguana over several decades has been mitigated by the enforcement of local regulation, however, practices continue on a smaller scale and are still common in some areas. Individuals are often confused with the Green Iguana, which is still legally killed for human consumption.
 
Natural predators continue to decimate numbers at all stages of the lifespan. While eggs are the main course for birds, opossums and other lizards, juveniles are targeted by the red-bellied racer snake and adults are at risk from feral dogs and larger, aggressive animals. On the islands of Antigua, Barbuda and St Maarten, populations are already extinct due to the introduction of the Indian Mongoose.
 
Either as escaped pets or stowaways, the Green Iguana has spread extensively from Central and South America to the Caribbean, disturbing the natural balance and behaviours of Lesser Antillean Iguanas. As a non-native reptile and a close relative, they compete for food, dominance, breeding partners and territories; further restricting distribution and capability to live to an expected lifespan of 15 years. Consistent interbreeding between the genera has successively caused hybridization and significantly contributed to genetic impurity.
 

Reptiles Facing Extinction?

 
From Sombrero and Anguilla in the north to Grenada in the south, the Lesser Antilles is renowned for its abundant endemism of plants and wildlife. For the Lesser Antillean Iguana, there is absolutely nowhere else it can be found. Combined with the countless threats over generations, this is what makes their existence so vital to preserve. We don’t want any more devastating agricultural practices and loss of habitat. We don’t want the IUCN to move their classification any further than endangered. And most importantly, we don’t want to see them taxidermied in museums under the heading ‘Extinct Reptiles’.
 
If we can ensure that the local people, wildlife authorities and even international conservation organisations are knowledgeable of their plight, and aware of strategies to assist in monitoring predators or creating safe, communal nesting sites, then this would be a step in the right direction to promoting a foreseeable future; and not one where Lesser Antillean Iguanas are a prehistoric creature of the past.
 

Get Involved

 
For further reading, please see the IUCN’s Conservation Action Plan for Lesser Antillean Iguanas here.
 
You can support on-ground conservation efforts and have fun! Download our mobile game app, World of the Wild! Click here to download.
 
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