Rhinoceros iguana in Cayo Iguana, Laguna de Oviedo. Photo Ariel Contreras

IGUANAS OF HISPANIOLA

We are the only Caribbean island with two endemic species of rock iguanas

Rock iguanas (genus Cyclura) are large, unique lizards of the West Indies. Only nine species exist today, and Hispaniola got lucky and has two: The rhinoceros iguana (Cyclura cornuta) and Ricord´s iguana (Cyclura ricordii). As a group, rock iguanas are considered the most threatened lizards in the world. Sadly, our species are also in this situation, being both considered endangered.

Like other iguanas, they are strong lizards, with lose skin around their necks and a ridge of scales running from the nape (back of the head) to the tip of the tail.  Rock iguanas are singled out by their large body size (up to one and a half metres in length) and their strong legs.   Our rock iguanas are the largest native terrestrial mammals still surviving in Hispaniola.  

Adult female Ricord´s iguana. Photo: Rafael Arvelo

Get to know them

Rhinoceros iguana

Cyclura cornuta

Its name comes from horn-like scales on top of its snout which remind us of a rinoceros. Its eyes are brown.  It also has horn-like scales on the timpanic (ear) area.  Body color is a shade of grey or brown, sometimes greenish.  It is the largest and heavier bodied of our two Hispaniolan species, reaching up to 70cm in body and head length + an equally long tail. It can make its dens on rocky or lose soil.  

Cyclura cornuta

 Whereas it used to inhabit many low-land and coastal areas across the entire island, today it only survives in certain localities of the Dominican Republic.  The rhinocerous iguana is considered endangered  (EN, according to the IUCN´s Red List of Threatened Species).    

Current distribution of Cyclura cornuta (source IUCN 2019)

Ricord´s iguana

Cyclura ricordii

 Its tail is covered by rings of spiny scales.  Its eyes are red.  Its color ranges from grey, greenish gray to beige, with dark stripes across its body.  Ridge scales are larger in the nape ad mid body area than in the rest of the body.  It can measure up to a 50 cm in lenght + an equally long tail.  Its dens are usually excavated in lose soil, where it digs underground tunnels of up to 5 metre-long tunnels. 

Cyclura ricordii

 It is only found in Isla Cabritos on Enriquillo Lake, on areas south of Enriquillo lake, in a small area east of Pedernales (Dominican Republic) and   Ansapit (Haití).  It is considered endangered  (EN, according to the IUCN´s Red List of Threatened Species).   

Current distribution of Cyclura ricordii (source IUCN 2019)

Dry forests are their home

In their natural habitats, our rock iguanas feed mostly on leaves, fruits and seeds from wild native plants.  They are very important for their ecosystem, because through their feeding they help disperse nutrients and seeds, helping in forest maintenance and through their moderate grazing, they stimulate plants to grow more and be healthy.  Without them, dry forests could not maintain or restore themselves, and they will lose many species, reducing its natural and rich biodiversity.

Bosque en la zona de La Trocha de Zuquete, Municipio Duvergé

In peril…

Despite their importance to ecosystems, each day we have less iguanas.  Feral dogs kill females when they lay their nests, cats prey on the newly hatched iguanas as they come out of the nest, farming keeps expanding into their habitats, charcoal making degrades their environment, and road kills keep happening.  Some humans hunt them for food.  If we don´t chang this, we will become extinct soon.

Agriculture expanding into their habitats
Habitat degradation caused by charcoal making
Feral dogs often kill gravid females
Feral cats prey upon the hatchlings
Roadkills are commonplace
Set trap to catch iguana at its den´s entrance

Conserving its critical habitats

Iguanas, like most reptiles, reproduce by laying eggs underground.  For this, they need safe places with lose soil, where they can incubate for about three months.  In certain areas where they live, such places are hard to find or are being replaced by agriculture.  One of our priorities has been to identify these breeding critical sites and monitoring their success.  Once identified and mapped, we have tried to defend them through advocacy for protected areas and land purchases.   

Revising nest of rhinocerous iguana

Research 

Since 2004, we have been working with national and international collaborators to study, monitor and protect iguanas, their nests and critical habitats.   This has included research on their genetics and natural history, and we have trained local assistants to conduct patrolling, quantify their abundance, revise nests and combat threats.   

Taking a sample for genetic studies

Habitat restoration 

Due to the severe degradation suffered by dry forests in the Dominican Republic due to charcoal making, lose livestock and wood extraction, we have started a program to restore these habitats for our two iguana species, especially Ricord´s iguana.   We are using some of the native pant species preferred by iguanas  in their diet, such as the tree cactus Consolea moniliformis (alpargata).  This work is carried out with a local team from Duvergé municipality.  

Restoration team

The iguanaria problem

Our rock iguanas are threatened by the proliferation of iguanaria (plural of iguanarios) in the Dominican Republic.  These businesses keep iguanas in captivity, especially rhinocerous iguanas as a visitor attraction.  Many lack the minimum space required for these territorial animals or don´t have the conditions to keep them healthy or in humane conditions.  Another problem is that instead of preserving local  threatened populations, they are moving and releasing iguanas from other populations across the country, eroding the local genetic variability which has helped them survive in each locality to the present day.  Furthermore, some iguanaria are facilitating the expansion of the green iguana (Iguana iguana), an invasive and introduced species to our island.  We are working with iguanaria staff to try to improve their practices. 

Equipo de restauración de hábitat de las iguanas

Education 

We have been spreading our messages to young and old across the country, especially in areas where the iguanas are found, with the help of  our mascots, Rina Rinoceronte (Rina Rhino) and Ricky Ricordi.  We are trying to create awareness on these magnificent reptiles and the threats they face.  

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With support from: