Crested Gecko

The crested gecko, also called the eyelash gecko, is a lizard native to southern New Caledonia, where it lives on the Isle of Pines and on parts of the main island, Grande Terre. It is mostly arboreal, favouring the lower canopy and understory of rainforest, and can jump long distances between branches. It is nocturnal, sleeping in secure spots in high branches by day, and it feeds opportunistically on fruit, nectar, pollen and insects. Adults measure 20 to 25 cm in total length. Hair-like projections above the eyes resemble eyelashes, and since it has no eyelids a transparent scale keeps each eye moist while the gecko clears debris with its tongue.

About the crested gecko

The crested gecko, also called the eyelash gecko, is a small tree-dwelling lizard in the gecko family Diplodactylidae. It is found only in the far south of New Caledonia, in the southwest Pacific. Named for the fringed crests over its eyes, it was thought extinct until its rediscovery in 1994.

The French zoologist Alphonse Guichenot first described the species in 1866 under the name Correlophus ciliatus. In 1883 it was moved to the genus Rhacodactylus, but later genetic work showed it was not closely related to some species in that group, and it has returned to Correlophus. The species name ciliatus comes from the Latin for "fringe" or "eyelashes."

That name points to the gecko's most recognizable feature. Above each eye is a row of hair-like projections that look like eyelashes. They continue as two rows of small spines running from the eyes along the sides of the wedge-shaped head and down the back to the base of the tail.

A crested gecko usually measures 20 to 25 cm (8 to 10 in) long, of which 10 to 15 cm (4 to 6 in) is tail. It comes in many natural shades, including grey, brown, red, orange and yellow. Wild animals show three basic pattern types, known as morphs: pattern-less, white-fringed and tiger.

Like many geckos, the crested gecko has no eyelids. A clear scale called a spectacle covers each eye and keeps it moist, and the gecko licks it clean with its tongue. The pupils are slits with lobed edges. Large light-sensing cones and wide pupils give a broad but short-sighted field of view, which helps when hunting at night.

The toes and the tip of the tail are covered in tiny hairs called setae. Each seta splits into hundreds of even finer branches called spatulae, about 200 nanometers across. These are thought to cling to surfaces using weak molecular attractions, letting the gecko walk up smooth surfaces such as glass and wood. Small claws on the toes help on rougher surfaces.

The tail is semi-prehensile and helps with climbing. Like many lizards, the crested gecko can drop its tail to distract a predator, breaking it at fixed weak points in the tail bones. Blood vessels close almost at once, so there is next to no bleeding, and the dropped tail keeps wriggling for about two to five minutes.

Unlike many lizards, however, the crested gecko does not regrow a lost tail. Most adults in the wild have no tail at all.

Behavior and diet

The crested gecko is mostly arboreal, living in the lower canopy and understory of New Caledonia's rainforests. It is nocturnal, spending daylight hours asleep in secure spots high in the branches and becoming active after dark. It can leap long distances from branch to branch.

It is an omnivore and an opportunist. Wild crested geckos eat fruit, nectar and pollen as well as a variety of insects.

Little is known about how crested geckos breed in the wild, and most of what is known comes from captive animals. A female usually lays two eggs per clutch, and the eggs hatch 60 to 150 days later.

A single mating is enough for a female to lay two eggs every four to six weeks over a breeding cycle that can last eight to ten months. Afterward, wild females go through a "cooling" period, usually triggered by small changes in temperature and daylight during winter, when they rebuild the body mass and nutrients lost to egg-laying.

Calcium is critical. Crested geckos store it in two small sacs on the roof of the mouth. A laying female that runs short of calcium can suffer a calcium crash, becoming shaky, sluggish and uninterested in food, and it can be fatal. Newly hatched geckos do not eat until after their first shed, when they eat their own skin; before that they live on what is left of their yolk.

Rodents and cats are the main predators. Pacific rats are thought to have reached New Caledonia about 3,000 years ago with the first Melanesian settlers, and ship rats and brown rats arrived in the 19th century. Crested gecko remains have been found in the stomachs of New Caledonian rodents, and because digested gecko remains are hard to identify, the toll may be underestimated.

Range and habitat

The crested gecko lives only in South Province, New Caledonia. There are three separate populations. One lives on the Isle of Pines and its surrounding islets. The other two are on the main island, Grande Terre: one around the Blue River provincial park and another farther north, just south of Mount Dzumac.

All three populations live in rainforest, where the geckos use the understory and lower canopy rather than the ground.

Crested gecko vs leopard gecko

The crested gecko and the leopard gecko are the two most widely kept geckos in the world, with the leopard gecko in first place. They are easy to tell apart once their lifestyles are compared.

Conservation status

The crested gecko is listed as Vulnerable on the IUCN Red List, in an assessment published in 2021. It was believed extinct before it was rediscovered in 1994 during an expedition led by the German herpetologist Robert Seipp. Along with several other New Caledonian geckos, it has been under consideration for protection under CITES, the treaty that regulates international wildlife trade.

The biggest single threat appears to be the little fire ant, an introduced species that attacks crested geckos in large numbers and competes with them for insect prey. Other threats include wildfires, predation by introduced rats and cats, and habitat damage from introduced rusa deer and pigs.

Export of wild crested geckos is now prohibited. Before New Caledonia stopped issuing permits, biologists exported a few animals for breeding and study, and those founders gave rise to captive lines in Europe and the United States. Today the crested gecko is one of the most widely kept and bred geckos in the world, second only to the leopard gecko.