Crested geckos, Rhacodactylus ciliatus, are a New Caledonian geckos that have made a huge splash in the pet trade in recent years. 

Why are "cresties" or "eyelash geckos" such great pets? The short answer is, "they're small (for a reptile),come in lots of colors, are friendly and don't mind being handled, don't need heat or UV lights in most circumstances, and don't have to eat live bugs."

Cresties were thought to be extinct for a good 40 years or so, but rediscovered in their native New Caledonian islands in 1994. Since their rediscovery and introduction to the pet trade, they have rapidly become the most popular gecko pet since Leopard geckos, nearly rivaling bearded dragons in their popularity.

Several hundred individuals were imported to the United States and Europe, before New Caledonia banned the export of the geckos, wanting to evaluate the conservation status of the animals. Crested geckos at this point are considered endangered in the wild, but are extremely secure in captivity.

 

Care:

Crested geckos are easy keepers.  Because they are nocturnal, they don't need UV to properly form healthy skeletons.  New Caledonia is temperate--keep in mind the islands are south of New Zealand--and cresties prefer a daytime temperature range of 65-80 F.  Overheating is more of a problem than being too cool. They can take night-time temperatures down into the low 50's, but temperatures over 85 for any extended period of time can be dangerous to them.

They don't need a whole lot of counter space for a cage, as they prefer vertical climbing space.  A 20L fish tank on its end, or an Exo-Terra or ZooMed terrarium, makes ideal caging for adults.  A 12x12x18 terrarium is the absolute minimum for an adult or a pair; larger colonies should be kept in 18x18x24 or larger.  Cages should have plenty of vines, braches, cork bark, or other things to climb about on.  Artificial plants are totally fine, although some keepers like to keep live plants instead.

There are many arguments about substrate. Nearly all keepers suggest keeping hatchlings and animals in quarantine on paper towel. Adults are often kept on eco earth or other coconut/coir fiber, peat, fine reptile or orchid bark, or a blend of them.  A blend of all three makes an excellent substrate for growing live plants in. Pothos, bromeliads, "lucky bamboo, dracaena, and other mid-moisture, low-light plants are excellent.

Cresties will drink water from a bowl quite readily, but misting the cage once a day or so, especially in dry weather, is never a bad idea.  Some cresties seem to prefer having their food and water above ground level, some do not seem to care.

Adult males should never be kept together, as they will fight with each other, but most females get along with one another, and up to 4 or 5 females can be kept in a colony with a single male.

Crested geckos are somewhat unusual as far as geckos go, because they do not regenerate their tails if they drop them.  Most other common pet species--and all other members of the Rhacodactylus genus--do regrow tails if they lose them. Tailless cresties are often affectionately called "frogbutts".

Crested geckos reach up to 10 inches, tail included, maybe 6 of that is body length in a mature animal. While this is large for a gecko, it's still small compared to other reptiles like chameleons, bearded dragons, skinks, etc.

The crestie lifespan is still unknown, but is guessed to be between 15 and 20 years. Many of the original imports from 1994 are still going strong and reproducing.

They by no means REQUIRE handling, and are totally fine being "observed only" pets, but they tolerate it better than most reptiles. Many cresties are happy to crawl all over their keepers, sit in their hair, ride on their shoulders, clamber around their desks. They should never be grabbed or gripped tightly, just let them climb on you, and should never be picked up by the tails.

 

Feeding:

This is the important part.   In the wild, cresties eat mostly fruit, and some bugs.   If you pick up a book on cresties in the store, or search the internet, you will see a lot of references to feeding them fruit flavored baby food. DO NOT DO THIS! 

All of this literature is from some years ago, before a commercially produced product called Crested Gecko Diet was introduced a few years back.  The "crested gecko diet", or CGD, is made by several companies, the most popular and available being by Allen Repashy, one of the individuals involved in the rediscovery, importation, and ongoing research of the species. The diet is nutritionally complete for the species and contains everything they need to thrive.

The biggest problem with feeding baby food is getting the nutrients right--and it has a lot of extra sugar, to boot. Some advanced owners and breeders still do so, blending baby food with calcium and vitamin powders, but getting the mix correct is a science. It is in no way suggested for beginners, as improper calcium levels can lead to the disease called MDB, or "Metabolic Bone Disease".  The vast majority of cases of MDB in cresties can be traced to a baby-food diet, or offspring of parents fed baby food.

Feed the CGD. It is easy and foolproof. Mix 2 parts water, 1 part powder, blend until the consistency resembles pudding.  Watch your cresties devour it.  Repeat in 24 hours.

Some geckos prefer the CGD freshly mixed, some seem to like it best a day old, so you can leave the dish in for 48 hours (60 in a real pinch) before changing it out.  Don't worry about it going off. If CGD has gone bad, it's easy to tell. After it's mixed, it's either rock hard, or molded. The powder is bad if it smells rancid.  

The basic form of CGD, available in most big box pet stores in the U.S., is called the "one part" mix. It has flavoring agents already added, and just needs to be mixed with water to be ready. The basic flavor has been changed over the years, to be as palatable as possible, but currently has some banana, rose, and fig flavorings in it. 

The more advanced version, the "two part" formula, comes with a bag of unflavored base--the nutritious part--and bags of pure flavoring, which the hobbyist can mix together. Flavors include peach, rose, mango, cherry, fig, strawberry, rose, papaya, passionfruit, banana, and others.  Some geckos do seem to prefer one flavor over others, some don't seem to care.

Cresteds CAN be fed bugs, if you want--but it's not required.  If bugs are offered--crickets, waxworms, or phoenix worms--they should be dusted with calcium powder.  Many hobbyists offer bugs once a week or so, for a treat and some stimulation for the geckos, but don't really use them as a daily part of the diet.  Bugs should never be the only diet offered to a crested gecko.

If a new crestie was fed only bugs or baby food, it can take up to 2 weeks to adapt them to CGD.  You'll need to do it "cold turkey".  They are fairly clever, and will learn to hold out for the food they prefer.  There are NO recorded cases of otherwise healthy cresties starving themselves to death. Once they're hungry enough, they will eat.  If you're seriously concerned, you can hand-feed them the CGD. Mix it up, put it on the end of a toothpick or baby spoon, hold the gecko on one hand, and dab the food little by little on their nose. They'll lick it off, and soon realize it tastes good.

 

Breeding:

Crested geckos, on top of their other awesome qualities, are remarkably easy to breed.  Put a pair together, you will have babies. 

Mature adult males can be easily identified by the "bulge" under their tail. The bulge is not in fact testes, no matter how much it looks like them, but in fact contains the hemipenes of the male, and the testes are internal.  Mature females have no bulge.

Young animals can be sexed from about 7 grams on using a jeweler's loupe to look for pores. Males have two to three rows of pores, usually with shiny centers, above the vent and along the insides of the legs.  Females lack pores.  Unfortunately, all animals "look" female until they suddenly develop pores and/or a bulge. It's generally a good idea to only consider an animal female if it's over 20 grams with no bulge and no pores under magnification.

Females lay 2 eggs per clutch, roughly a clutch a month, for the better part of a year. The standard breeding season is about March to November.  A healthy pair often produces 10-14 offspring a year.

Females will dig to lay their eggs.  If you have a natural planted tank, she will just find a spot and dig. If you have a thin layer of substrate, or use paper towel, she will need a lay box.  A tupperwear container with half the lid removed, filled with eco earth to a depth of at least 3-4 inches, is ideal.  Most females will use this instinctively.

When eggs are removed from the lay box or tank, be careful not to turn them. If you're not sure how they were oriented, shine a flashlight or LED through the egg. A red circle, the "magic cheerio", will show on a fertile egg. The circle should be placed on top. Mark the top of the egg with a sharpie or soft pencil so they can be reoriented properly if they get disturbed.

Incubation is equally easy. Unlike many eggs, these can sit at room temperature and thrive. Put them in a deli cup or tupperwear full of moistened vermiculite or perlite, marked sides up. Check the moisture every week or so--it should be damp, never soggy, never dry.  Wait.

Eggs hatch anywhere between 60-120 days (2-4 months). Eggs laid early and late in the season tend to take longer, those in the middle of summer often pop out at 2 months on the nose.

Hatchlings may not eat for 2-5 days (offer food anyhow) because they will still have yolk in their gut, but care is identical to that of adults.

Females should be given at least 3 months off each year, in the winter. Remove the male from the tank, put him in his own container (a Kritter Keeper or something similar is fine for short term), and give her some time to bulk up, rebuild her calcium reserves, and get some rest.

 

Resources:

http://www.reptiles.repashy.com/resources_RUSA_article.htm

http://www.pangeareptile.com/id52.htm

http://www.jbscresties.com/

Personal experience