Cyclura ricordi
Encyclopedia
The Hispaniolan Ground Iguana, Ricord's Ground Iguana, Ricord's Rock Iguana, or Ricord's Iguana (Cyclura ricordi) is a critically endangered species of rock iguana
.
It is found on the island of Hispaniola
in the Dominican Republic
and Haiti
, and is the only known species of rock iguana to coexist with the Rhinoceros Iguana
(Cyclura cornuta). Its natural habitat
is dry savanna
within three subpopulations in the Southwestern Dominican Republic. It is threatened by habitat loss due to agricultural encroachment.
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 iguanas. Its specific name is a Latinized form of French Biologist
, Alexandre Ricord's last name; Ricord first wrote of the species in 1826.
Morphological and genetic data indicate that the closest living relative of C ricordi is C. carinata of the Turks and Caicos Islands
.
with a body length of 49–51 cm in males and 40–43 cm in females with an equally long tail. Ricord's iguana's toes are articulated to be efficient in digging and climbing trees.
Their body color is a grayish green flat color marked by five to six bold pale gray chevrons alternating with dark gray to black chevrons. In adults, the dark chevrons are less contrasting than in juveniles. Ricord's iguana's eyes have a dark almost black iris
and red sclera
.
Males of this species, like other species within the Genus Cyclura, are larger than females, and have more prominent dorsal
crests in addition to prominent femoral pore
s on their thighs, which are used to release pheromones. Females have less prominent pores and have shorter crests than the males making the animals sexually dimorphic
.
Ricord's iguanas have excellent vision, which allows them to detect shapes and motions at long distances. As Ricord's iguanas have only a few Rod cell
s they have poor vision in low-light conditions. At the same time they have cells called “double cone
s” which give them sharp color vision and enable them to see ultraviolet
wavelengths. This ability is highly useful when basking so the animal can ensure that it absorbs enough sunlight in the forms of UVA
and UVB to produce Vitamin D
.
Like other Cyclura iguanas, Ricord's iguanas have evolved a white photosensory organ on the top of their heads called the parietal eye
, which are also called third eye, pineal eye or pineal gland. This “eye” doesn’t work the same way as a normal eye does as it has only a rudimentary retina and lens and thus, cannot form images. It is however sensitive to changes in light and dark and can detect movement.
Primarily herbivorous, Ricord's iguanas are presented with a special problem for osmoregulation
: plant matter contains more potassium
and as it has less nutritional content per gram, more must be eaten to meet the lizard's metabolic needs. As Ricord's iguanas are not capable of creating liquid urine more concentrated than their bodily fluids, like bird
s they excrete nitrogenous wastes as urate salts through a salt gland
. As a result, Ricord's iguanas have developed this lateral nasal gland to supplement renal salt secretion by expelling excess potassium and sodium chloride.
revealed that seeds passing through the digestive tracts of Cycluras germinate more rapidly than those that do not. The seeds in the fruits consumed by Cyclura iguanas have an adaptive advantage by sprouting before the end of very short rainy seasons. Ricord's iguana is an important means of distributing these seeds to new areas (particularly when females migrate to their nesting areas) and, as one of the largest native herbivores of their Hispaniola's ecosystem
, they are essential for maintaining the balance between climate and vegetation.
whereas juveniles tend to occupy arboreal retreats.
Ricord's iguana is found only in the southwestern Dominican Republic
, where it is restricted to the arid Valle de Neiba and the most xeric portion of the Peninsula de Barahona coastal lowlands. These two populations are separated by the Sierra de Bahoruco (Massif de la Selle in Haiti
), with three peaks exceeding 2000m that form an extensive ecological barrier. Past drier Pleistocene
climates may have allowed genetic exchange between the two subpopulations. Throughout their range, Ricord's iguanas coexist with rhinoceros iguana
s and both species have been observed swimming and floating in freshwater by herpetologist Jose Ottenwalder. All other Caribbean islands, if they do have a rock iguana species, are home to a single species.
grazing as well as charcoal
mining
. The iguanas are hunted and trapped as a food source by humans and killed by goatherders under the false superstition that iguanas rip open the bellies of livestock with their pointed crests. Competition from domestic and feral
livestock is also a concern as is predation of juveniles by cat
s and mongoose
. They are also poached for the illegal exotic animal trade, commanding a high price with collectors.
. The Indianapolis Zoo
has been involved in the Dominican Republic
for almost ten years and will continue its research and conservation efforts with the Ricord's iguana. The zoo's Project Iguana aids the survival of West Indian Iguanas and their habitats through in-site conservation, captive breeding, public education, and scientific research.
The project's goals are:
- to work with the Ricord's Iguana Recovery Group to implement the ISG's Species Recovery Plan
- to conduct a census of iguanas on Isla Cabritos, Dominican Republic.
- to determine vitamin D status of captive West Indian iguanas at the Zoo before and after exposure to sunlight
- to work in partnership with ZOODOM (the national zoo of the Dominican Republic) to develop a long-term captive breeding and husbandry program for Ricord’s iguanas.
- to develop an education program for West Indian Iguanas and their habitats.
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...
.
It is found on the island of Hispaniola
Hispaniola
Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...
in the Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
and Haiti
Haiti
Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...
, and is the only known species of rock iguana to coexist with the Rhinoceros Iguana
Rhinoceros Iguana
The Rhinoceros Iguana is a threatened species of lizard in the family Iguanidae that is primarily found on the Caribbean island of Hispaniola, shared by the Republic of Haiti and the Dominican Republic. They vary in length from 61 to 137 cm and skin colors range from a steely gray to a dark green...
(Cyclura cornuta). Its natural habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
is dry savanna
Savanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
within three subpopulations in the Southwestern Dominican Republic. It is threatened by habitat loss due to agricultural encroachment.
Taxonomy
Its 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 iguanas. Its specific name is a Latinized form of French Biologist
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
, Alexandre Ricord's last name; Ricord first wrote of the species in 1826.
Morphological and genetic data indicate that the closest living relative of C ricordi is C. carinata of the Turks and Caicos Islands
Turks and Caicos Islands
The Turks and Caicos Islands are a British Overseas Territory and overseas territory of the European Union consisting of two groups of tropical islands in the Caribbean, the larger Caicos Islands and the smaller Turks Islands, known for tourism and as an offshore financial centre.The Turks and...
.
Anatomy and morphology
Ricord's iguana is a large species of rock iguanaRock Iguana
Rock Iguana may refer to:* The Rock Iguana, Iggy Pop, American punk rock singer and occasional actor* Rock iguana any species of the Genus Cyclura, that are found in the West Indies...
with a body length of 49–51 cm in males and 40–43 cm in females with an equally long tail. Ricord's iguana's toes are articulated to be efficient in digging and climbing trees.
Their body color is a grayish green flat color marked by five to six bold pale gray chevrons alternating with dark gray to black chevrons. In adults, the dark chevrons are less contrasting than in juveniles. Ricord's iguana's eyes have a dark almost black iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
and red sclera
Sclera
The sclera , also known as the white or white of the eye, is the opaque , fibrous, protective, outer layer of the eye containing collagen and elastic fiber. In the development of the embryo, the sclera is derived from the neural crest...
.
Males of this species, like other species within the Genus Cyclura, are larger than females, and have more prominent dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
crests in addition to prominent 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 their thighs, which are used to release pheromones. Females have less prominent pores and have shorter crests than the males making the animals 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:...
.
Ricord's iguanas have excellent vision, which allows them to detect shapes and motions at long distances. As Ricord's iguanas have only a few Rod cell
Rod cell
Rod cells, or rods, are photoreceptor cells in the retina of the eye that can function in less intense light than can the other type of visual photoreceptor, cone cells. Named for their cylindrical shape, rods are concentrated at the outer edges of the retina and are used in peripheral vision. On...
s they have poor vision in low-light conditions. At the same time they have cells called “double cone
Cone cell
Cone cells, or cones, are photoreceptor cells in the retina of the eye that are responsible for color vision; they function best in relatively bright light, as opposed to rod cells that work better in dim light. If the retina is exposed to an intense visual stimulus, a negative afterimage will be...
s” which give them sharp color vision and enable them to see ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
wavelengths. This ability is highly useful when basking so the animal can ensure that it absorbs enough sunlight in the forms of UVA
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
and UVB to produce Vitamin D
Vitamin D
Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....
.
Like other Cyclura iguanas, Ricord's iguanas have evolved a white photosensory organ on the top of their heads called the parietal eye
Parietal eye
A parietal eye, also known as a parietal organ or third-eye or pineal eye, is a part of the epithalamus present in some animal species...
, which are also called third eye, pineal eye or pineal gland. This “eye” doesn’t work the same way as a normal eye does as it has only a rudimentary retina and lens and thus, cannot form images. It is however sensitive to changes in light and dark and can detect movement.
Primarily herbivorous, Ricord's iguanas are presented with a special problem for osmoregulation
Osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content; that is it keeps the organism's fluids from becoming too diluted or too concentrated. Osmotic pressure is a measure of the tendency of water to move...
: plant matter contains more potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
and as it has less nutritional content per gram, more must be eaten to meet the lizard's metabolic needs. As Ricord's iguanas are not capable of creating liquid urine more concentrated than their bodily fluids, like bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s they excrete nitrogenous wastes as urate salts through a salt gland
Salt gland
The salt gland is an organ for excreting excess salts. It is found in elasmobranchs, seabirds, and some reptiles. In sharks, salt glands are found in the rectum, but in birds and reptiles, they are found in or on the skull, in the area of the eyes, nostrils or mouth. In crocodiles, the salt is...
. As a result, Ricord's iguanas have developed this lateral nasal gland to supplement renal salt secretion by expelling excess potassium and sodium chloride.
Diet
Ricord's iguana, like most Cyclura ssp is primarily herbivorous, consuming leaves, flowers, berries, and fruits from different plant species. A study in 2000 by Dr Allison Alberts of the San Diego ZooSan Diego Zoo
The San Diego Zoo in Balboa Park, San Diego, California, is one of the most progressive zoos in the world, with over 4,000 animals of more than 800 species...
revealed that seeds passing through the digestive tracts of Cycluras germinate more rapidly than those that do not. The seeds in the fruits consumed by Cyclura iguanas have an adaptive advantage by sprouting before the end of very short rainy seasons. Ricord's iguana is an important means of distributing these seeds to new areas (particularly when females migrate to their nesting areas) and, as one of the largest native herbivores of their Hispaniola's ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
, they are essential for maintaining the balance between climate and vegetation.
Distribution and habitat
Ricord's iguana inhabits dry xeric scrubland with sandy and earthen soils in which they excavate burrows for retreats and nest sites that they expand over time. Entrances to these burrows are generally dug under dense thorny vegetation, shrubs, stumps, or exposed rocks. The adults of the species are primarily terrestrialTerrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
whereas juveniles tend to occupy arboreal retreats.
Ricord's iguana is found only in the southwestern Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
, where it is restricted to the arid Valle de Neiba and the most xeric portion of the Peninsula de Barahona coastal lowlands. These two populations are separated by the Sierra de Bahoruco (Massif de la Selle in Haiti
Haiti
Haiti , officially the Republic of Haiti , is a Caribbean country. It occupies the western, smaller portion of the island of Hispaniola, in the Greater Antillean archipelago, which it shares with the Dominican Republic. Ayiti was the indigenous Taíno or Amerindian name for the island...
), with three peaks exceeding 2000m that form an extensive ecological barrier. Past drier Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
climates may have allowed genetic exchange between the two subpopulations. Throughout their range, Ricord's iguanas coexist with rhinoceros iguana
Rhinoceros Iguana
The Rhinoceros Iguana is a threatened species of lizard in the family Iguanidae that is primarily found on the Caribbean island of Hispaniola, shared by the Republic of Haiti and the Dominican Republic. They vary in length from 61 to 137 cm and skin colors range from a steely gray to a dark green...
s and both species have been observed swimming and floating in freshwater by herpetologist Jose Ottenwalder. All other Caribbean islands, if they do have a rock iguana species, are home to a single species.
Mating
Mating occurs from May through June. Copulation is preceded by numerous head-bobs on the part of the male, who then circles around behind the female and grasps the nape of her neck. He then attempts to restrain the female in order to maneuver his tail under hers to position himself for intromission. Copulation generally lasts from 30 to 90 seconds, and a pair is rarely observed mating more than once or twice a day. Anywhere from two to eighteen eggs are usually laid in June or July depending on the size and age of the female, in nests excavated in pockets of earth exposed to the sun. The eggs go through a 90 to 100 day incubation period hatching in September and October. It has been noted that Cyclura eggs are some of the largest eggs laid by any lizard.Threats
On the Barahona Peninsula, the population of Ricord's iguanas has been threataned by agricultural displacement through increased farming and cattleCattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
grazing as well as charcoal
Charcoal
Charcoal is the dark grey residue consisting of carbon, and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis, the heating of wood or other substances in the absence of oxygen...
mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
. The iguanas are hunted and trapped as a food source by humans and killed by goatherders under the false superstition that iguanas rip open the bellies of livestock with their pointed crests. Competition from domestic and feral
Feral
A feral organism is one that has changed from being domesticated to being wild or untamed. In the case of plants it is a movement from cultivated to uncultivated or controlled to volunteer. The introduction of feral animals or plants to their non-native regions, like any introduced species, may...
livestock is also a concern as is predation of juveniles by cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s and mongoose
Mongoose
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"...
. They are also poached for the illegal exotic animal trade, commanding a high price with collectors.
Conservation
The estimated wild population is only 2,000-4,000 animals making this species critically endangeredCritically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
. 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...
has been involved in the Dominican Republic
Dominican Republic
The Dominican Republic is a nation on the island of La Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are shared by two countries...
for almost ten years and will continue its research and conservation efforts with the Ricord's iguana. The zoo's Project Iguana aids the survival of West Indian Iguanas and their habitats through in-site conservation, captive breeding, public education, and scientific research.
The project's goals are:
- to work with the Ricord's Iguana Recovery Group to implement the ISG's Species Recovery Plan
- to conduct a census of iguanas on Isla Cabritos, Dominican Republic.
- to determine vitamin D status of captive West Indian iguanas at the Zoo before and after exposure to sunlight
- to work in partnership with ZOODOM (the national zoo of the Dominican Republic) to develop a long-term captive breeding and husbandry program for Ricord’s iguanas.
- to develop an education program for West Indian Iguanas and their habitats.