In 1866, Crested geckos were described by Alphone Guichenot. After this, the species was not observed again for over a century. In 1994 this species was rediscovered by Robert Seipp and Phillippe de Vosjoli. Upon being rediscovered, live specimens were collected for research and the pet trade. Today, crested geckos are becoming increasingly common in captivity.
New Caledonia’s large diversity of climate, soils, and geography (especially topographical diversity) has resulted in a large array of biological variation. The genus Rhacodactylus contains five endemic New Caledonian species of gecko in addition to this one (R. auriculatus, R. chahoua, R. leachianus, R. sarasinorum, and H. duvaucelii). In addition to these closely related species, three species of Rhacodactylus exist outside of the island and are endemic to northern Australia.
One of the main predators of crested geckos are little fire ants, which have been introduced to New Caldonia and will swarm and bite the geckos. Other predators include dogs, cats, rats, snakes, and other geckos, many of which are introduced species as well. Crested geckos exhibit caudal autotomy and can drop their tails if in danger from a predator. Vasoconstrictor mechanisms prevent the tail from bleeding and small fractures in the tail bone allow the tail to break off at predetermined segments. After being dropped, the tail will continue to move for 3-5 minutes, distracting the predator as the gecko escapes. These geckos can not re-grow their tails, which can cause them to become less agile.
Known Predators:
Crested geckos have a relatively large, triangular head, with two large eyes and two relatively large ear openings on either side of the head. Very fine light tan, peach, or reddish brown-colored granular scales cover their long bodies. They have moderately thick, prehensile tails. The back typically has a pattern of lateral, darker stripes. Thin, continuous, calcareous crest, project along either side of the back and also above the eyes and portions of the limbs. Above the eyes, these crests seem to serve primarily to keep dust and other particles out, but it is unknown what purpose is served by the dorsal and limb crests; they may be used in discriminating between potential mates. There are three color morphs that appear in wild crested geckos: patternless, tiger, and white-fringed. Patternless crested geckos are more or less solid in color, ranging from yellow, green, brown, red, to gray, and have very faint or no pattern present on the back. Tiger crested geckos have a light colored background with deep, dark, contrasting stripes and a patterned belly. White-fringed crested geckos are characterized by white or yellow coloration on all or a portion of the calcareous crest. In addition to these three patterns, there are many other variations that are distinct in captive bred individuals but are not found in the wild.
Crested geckos have four limbs, each ending in four fingers; at the bottom of each finger is a network of hairs (setae) which allow them to walk on very smooth vertical surfaces. These pads are especially important in tree climbing. Crested geckos also have a prehensile tail with setae at the tip, adding extra support when hanging from tree branches or trying to regain balance; unlike many species, these geckos can not re-grow their tails if lost. Adult crested geckos typically average 20.3 centimeters in total length and 10.2-11.9 centimeteres snout-to-vent length (SVL). These geckos lack eyelids, though they do have a clear protective covering over each eye. They must lick their eyes with their tongues periodically in order to keep them clean and moist. Crested geckos have a small opening, covered in a tympanic membrane, on each side of side of the head, which acts as an ear.
Range mass: 30 to 35 g.
Average length: 20.3 cm.
Sexual Dimorphism: sexes alike
Crested geckos are thought to be able to live for over 20 years in captivity, though there is some uncertainty; they have only recently been reintroduced to science and the pet trade (1994) after having been assumed extinct. No information regarding lifespan in the wild is currently available.
Range lifespan
Status: captivity: 10 to 20 years.
There are three distinct and disjunct populations of crested geckos: one on the Isle of Pines, and two on Grand Terre. The southeastern rainforests of Grand Terre, the main island of New Caledonia where crested geckos are primarily found, are divided by the highest peak on the island, Mont Paniė (1628 meters above sea level). This greatly influences climate and soil type in the region. High and low temperatures can range from 11.1-27.8°C, though temperatures typically range from 22.2-23.9°C. This area is tropical rainforest with precipitation levels potentially as high as 400 cm per year. They are most typically found at elevations from 150-1000 meters above sea level. Crested geckos spend daytime hours resting in thick vegetation near the forest floor, where it is cooler and less sunny. At night they spend much of their time foraging in shrubs and lower portions of the canopy, rarely traveling much higher than 3 m from the forest floor.
Range elevation: 150 to 1000 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
Crested geckos are endemic to the islands of Grand Terre (Provence Sud), and the Isle of Pines, New Caledonia. There are unconfirmed reports of these geckos from Kôtomo Island, New Caledonia.
Biogeographic Regions: australian (Native )
Other Geographic Terms: island endemic
Crested geckos are omnivores, feeding primarily on insects, nectar, and fruits, hunting and feeding at night. Calcium and Vitamin D3 are vital for the proper growth and development of crested geckos, especially for young individuals. Deficiencies can result in metabolic bone diseases, which can be fatal, so they have endolymphatic sacs on the roofs of their mouths for calcium storage.
Animal Foods: insects
Plant Foods: fruit; nectar; sap or other plant fluids
Primary Diet: carnivore (Insectivore ); herbivore (Frugivore , Nectarivore , Eats sap or other plant foods); omnivore
Very little is known of the role that crested geckos have in their ecosystem. One reason for this is that, for more than a century, crested geckos were believed to be extinct. In 1994 they were rediscovered and most of the studies and observations carried out following their rediscovery were on captive bred individuals. Crested geckos are likely important in the distribution of pollen for various nectar and fruiting plants. These geckos have been found to host parasitic amoebas and protozoans.
Ecosystem Impact: pollinates
Commensal/Parasitic Species:
Crested geckos are a favorite in the pet trade because they are very docile and are easy to maintain. The wide availability of crested geckos may help to draw attention to the 41 regionally endemic species of reptiles present on New Caledonia and the importance of protecting them. An interest in preserving these habitats could then play some role in increasing wildlife research and conservation efforts on these islands.
Positive Impacts: pet trade ; research and education
There are no known adverse effects of crested geckos on humans.
Information regarding development in this species has not been gathered in the wild, but has been extensively recorded in captivity. It has been found that temperature is a determining factor on rate of development, offspring size, and sex. In particular, sex is not determined genetically but after egg laying, by environmental temperature. Evidence suggests that warmer incubation temperatures lead to higher proportions of males and colder incubation temperatures lead to higher proportions of females. It has also been observed that crested gecko eggs kept at higher temperatures during incubation develop faster than eggs kept at lower temperatures.
After hatching, young crested geckos will not eat for 3-5 days (until they shed their skins for the first time), using stored yolk remains for sustenance. After this period of time, hatchlings will begin searching for food such as nectar, fruits, and small insects.
Development - Life Cycle: temperature sex determination; indeterminate growth
Little is known about crested geckos in their natural environments, and even less in known about the impact of human activities on their populations. Slash and burn agriculture, deforestation, and mining (nickel, cobalt and chromium), as well as the introduction of non-native species are all believed to be threats to crested geckos and they are classified by The IUCN Red List as "Vulnerable", with a downward population trend. The primary indigenous conservation organization on New Caledonia, the Association pour la Savvegarde de la Nature NėoCalėdonienne (ASNNC) is currently working with the government to protect more land and habitat and raise awareness about the reptilian fauna of the islands. The other organization working to protect this environment is the Center of Initiation of the New Caledonia Environment. The hope is that laws will eventually be passed to protect the terrestrial reptilian fauna there.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Crested geckos use a high pitched chirping sound that is primarily used to call for a mate and as a defense mechanism to frighten a predator in an attempt to escape. They also use visual cues; if startled, crested geckos have been known to rise up on their hind legs and open their mouths wide in a threatening posture, and mating involves jerky body motions from the male.
Crested geckos have specialized eyes for seeing in the dark. Like other gekkonid species, crested geckos have what has been referred to as Gehyra pupils; instead of having vertical, slit-shaped pupils with smooth edges, geckos have vertical, slit-shaped pupils with slightly lobed edges. They have color vision, as their retinas contain only cones. Nocturnal geckos such as these have larger apertures and cones, in addition to a shorter viewing length, than diurnal reptiles. This allows them to absorb as much light and see as much as possible in the dark.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
Mating behaviors have yet to be observed in the wild. Captive males have been known to fight violently if forced into contact with each other, especially during breeding season, and so multiple breeding females are kept with one male. A male will approach a female with jerky movements and, if she is willing, she will remain still while he climbs on her back and bites her neck as copulation begins.
Mating System: polygynous
Males become sexually mature between 9-12 months of age and females typically become mature at 12 months at a weight of 30-35 gm. At 3-4 months old, an external hemipenal bulge becomes visible in males, located at the base of the tail near the vent. In contrast, females are flat at the base of their tails, with much smaller bulges. Females are capable of laying 2 eggs every 4-6 weeks and do so 30-40 days after copulation; they retain sperm and may lay up to 4 eggs before copulating again. Breeding and egg laying takes place 8-10 months of the year, with a shift to lower temperatures halting egg production. If this resting period does not occur, females may lay eggs year round and are at risk of suffering severe calcium deficiencies. Eggs can be as large as 11x24 mm and 1.2-2.8 gm, and hatch 60-150 days after being laid. Young are independent at hatching.
Breeding interval: Breeding may occur every 4-6 weeks.
Breeding season: Egg laying takes place 8-10 months of the year; it may occur year round if there is no cooling cycle.
Range number of offspring: 2 (low) .
Range gestation period: 90 to 190 days.
Average age at sexual or reproductive maturity (female): 1 years.
Range age at sexual or reproductive maturity (male): 9 to 12 months.
Key Reproductive Features: iteroparous ; year-round breeding ; sexual ; fertilization ; oviparous ; sperm-storing
Males exhibit no parental investment beyond fertilization. Females allocate nutrients to their eggs (moreso because of their small clutches) and lay their eggs in a hole a few inches deep, safe from predators, and within an appropriate proper temperature range and soil moisture, allowing for gas exchange through the egg membrane. After laying her eggs, the female does not provide any additional parental care to her developing offspring.
Parental Investment: female parental care ; pre-fertilization (Provisioning)
The crested gecko or eyelash gecko (Correlophus ciliatus) is a species of gecko native to southern New Caledonia (France). In 1866, the crested gecko was described by French zoologist Alphonse Guichenot.[1][2] This species was thought to be extinct until it was rediscovered in 1994 during an expedition led by Robert Seipp.[3][4] Along with several other New Caledonian gecko species, it is being considered for protected status by the Convention on the International Trade in Endangered Species of Wild Flora and Fauna.
The species was first described in 1866 as Correlophus ciliatus by the Alphone Guichenot in an article entitled "Notice sur un nouveau genre de sauriens de la famille des geckotiens du Muséum de Paris" ("Notes on a new species of lizard in the gecko family") in the Mémoires de la Société Scientifique Naturelle de Chérbourg.
It was later renamed Rhacodactylus ciliatus. Recent phylogenetic analysis indicates that R. ciliatus and R. sarasinorum are not closely related to the other giant geckos, so these two species have been reclassified from Rhacodactylus back to the genus Correlophus.[5]
The specific name, ciliatus, is Latin, from cilia ("fringe" or "eyelashes") and refers to the crest of skin over the animal's eyes that resembles eyelashes.
The crested gecko is endemic to South Province, New Caledonia. There are three disjunct populations, one found on the Isle of Pines and surrounding islets, and there are two populations found on the main island of Grande Terre. One population is around the Blue River, which is a protected provincial park, and the other is further north, just south of Mount Dzumac. They are seen around many tropical climates.
Crested geckos typically range from 6–10 inches (15–25 cm) in length, including 4–6 inches (10–15 cm) of tail length.[3] Among the most distinctive features of these geckos are the hair-like projections found above the eyes, which greatly resemble eyelashes. This projections continue as two rows of spines that run from the eyes to the sides of their wedge-shaped head and continue to the base of their tail. Crested geckos do not have eyelids. Instead, a transparent scale, or spectacle, keeps each eye moist, and the geckos use their tongues to clear away debris.[6]
These geckos possess a semi-prehensile tail which they use to assist in climbing. The tail can be dropped (via caudal autotomy) to distract predators. Crested geckos do not regenerate their tails once lost; most adults in the wild lack tails.[4]
The toes and the tip of the semi-prehensile tail are covered in small hairs called setae. Each seta is divided into hundreds of smaller (approximately 200 nanometres in diameter) hairs called spatulae. It is believed these structures exploit the weak van der Waals force to help the gecko climb on most solid surfaces, most easily on flatter, smoother surfaces such as glass or wood. The toes have small claws which aid in climbing surfaces to which their toes cannot cling.
The crested gecko has many naturally occurring color groups, including grey, brown, red, orange, and yellow of various shades. They have three color morphs in the wild, which include pattern-less, white-fringed, and tiger.[7]
Crested geckos are a mostly arboreal species, preferring to inhabit the canopy of the New Caledonia rainforests. They are able to jump long distances between branches to move to new locations. Crested geckos are nocturnal, and will generally spend the daylight hours sleeping in secure spots in high branches.[1][8][9][10] Crested geckos are omnivores, and will opportunistically feed on fruit, nectar, pollen, and a variety of insects.[8]
Crested geckos were believed to be extinct prior to rediscovery in 1994.[4] The species is currently being assessed for CITES protection and vulnerable status.[11] The biggest single threat to the wild population appears to be the introduction of the little fire ant (Wassmania auropunctata) to New Caledonia.[8] The ants prey on the geckos, stinging and attacking in very large numbers, and they also compete with the geckos for food by preying on arthropods. Other threats to the wild population include habitat damage from wildfires, rodent predation, and habitat degradation from introduced deer and pigs.[12]
Little is known about the wild reproductive behavior of crested geckos; available information has been obtained from captive animals. Females generally lay two eggs per clutch, which hatch 60–150 days after they are laid. A female crested gecko only has to mate with a male once in order to lay 2 eggs every 4–6 weeks for a breeding cycle of upwards of 8–10 months. After a breeding cycle females in the wild go through a "cooling" cycle, usually prompted by slight temperature and daylight changes over the winter season.[13] During this time, the females are able to regain the body mass and nutrients they lost during egg-laying.
Crested geckos have two small sacs for calcium on the roof of their mouths. If an egg-laying female does not have enough calcium her sac will be depleted, and she can suffer from calcium deficiency. This can lead to a calcium crash, where the female appears shaky or wobbly, lethargic, has a lack of appetite, and can even result in death.[8]
Newly hatched crested geckos will generally not eat until after they have shed and eaten their skin for the first time, relying on the remains of their yolk sack for nutrition.[8]
Though the export of wild crested geckos is now prohibited, biologists exported several specimens for breeding and study before New Caledonia stopped issuing permits to export the species. From these specimens, different breeding lines were established, both in Europe and the United States. The crested gecko is now one of the most widely-kept and bred species of gecko in the world, second only to the common leopard gecko.[8]
Crested geckos can be very long-lived. While they have not been kept in captivity long enough for a definitive life span to be determined, they have been kept for 15–20 years or more.[14]
The crested gecko or eyelash gecko (Correlophus ciliatus) is a species of gecko native to southern New Caledonia (France). In 1866, the crested gecko was described by French zoologist Alphonse Guichenot. This species was thought to be extinct until it was rediscovered in 1994 during an expedition led by Robert Seipp. Along with several other New Caledonian gecko species, it is being considered for protected status by the Convention on the International Trade in Endangered Species of Wild Flora and Fauna.
