About Correlophus ciliatus Guichenot, 1866
Correlophus ciliatus, commonly called the crested gecko, usually measures 8–10 inches (20–25 cm) in total length, 4–6 inches (10–15 cm) of which is tail length. One of its most distinctive features is a set of hair-like projections above the eyes that resemble eyelashes. These projections continue into two rows of spines that run from the eyes along the sides of its wedge-shaped head all the way to the base of the tail. Crested geckos do not have eyelids. Instead, a transparent scale called a spectacle keeps each eye moist, and the gecko uses its tongue to clear debris from its eyes. This species has Gehyra pupils, which are slit-shaped with lobed edges. It has large cones and apertures that give it a wide but short-sighted view, which helps with nocturnal hunting. The crested gecko has a semi-prehensile tail that it uses to assist with climbing. The tail can be dropped through a process called caudal autotomy to distract predators; drop points are predetermined at specific segments where small fractures form in the tail bone. Unlike some species, the crested gecko does not regenerate its tail after it is lost, and most wild adults do not have tails. When the tail is dropped, the capillaries in the tail close almost immediately, resulting in almost no blood loss. The dropped tail continues to move for 2–5 minutes after separation. 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 hairs, called spatulae, that are approximately 200 nanometres in diameter. These structures are believed to use weak van der Waals force to help the gecko climb on most solid surfaces, climbing most easily on flatter, smoother surfaces like glass or wood. The toes also have small claws that help the gecko climb surfaces that its toes cannot cling to. The crested gecko has many natural color groups covering various shades of grey, brown, red, orange, and yellow. In the wild, it occurs in three color morphs: pattern-less, white-fringed, and tiger. This species is endemic to South Province, New Caledonia. There are three separate disjunct populations: one on the Isle of Pines and its surrounding islets, and two on the main island of Grande Terre. On Grande Terre, one population lives around the Blue River protected provincial park, and the other lives farther north, just south of Mount Dzumac. The crested gecko is a mostly arboreal species that prefers to live in the canopy of New Caledonia's rainforests. It can jump long distances between branches to move to new locations. It is nocturnal, and generally spends daylight hours sleeping in secure spots on high branches. Little is known about the crested gecko's reproductive behavior in the wild; most available information comes from observations of captive animals. Females generally lay two eggs per clutch, which hatch 60–150 days after being laid. A female only needs to mate once to produce clutches of two eggs every 4–6 weeks for a breeding cycle that lasts 8–10 months or longer. After a breeding cycle, wild females go through a "cooling" cycle, usually triggered by slight changes in temperature and daylight during the winter season. During this cooling period, females regain the body mass and nutrients they lost while laying eggs. The crested gecko has two small calcium sacs on the roof of its mouth. If an egg-laying female does not get enough calcium, her calcium sacs will be depleted, and she can develop calcium deficiency. This can lead to a condition called calcium crash, which causes the female to appear shaky or wobbly, become lethargic, lose her appetite, and can even result in death. Calcium supplements are available for captive crested geckos, but it is unknown how wild individuals get enough calcium. Newly hatched crested geckos generally do not eat until after they have shed and eaten their first skin; they rely on the remains of their yolk sack for nutrition until this point.
