Choosing a Giant Day Gecko
R.D. and Patti Bartlett
The giant day gecko is a remarkably beautiful lizard that has become very popular. It is quite hardy but, because it is nervous and its skin tears readily, is not easy to handle. It is also quite active. Unlike most geckos, the appropriately named day geckos are diurnal in their activity patterns, meaning they come to life during the day.
Giant day geckos, known by the scientific name Phelsuma madagascariensis grandis, are 9 to 11 inches long, one of the largest of all geckos, which range from 3 to 12 inches. Their ground color is a brilliant Kelly green and they have patches of brilliant orange on the face and the back.
Day geckos should be provided a cage of reasonable size – 29 gallons or larger for a pair or trio – but once established in their cage, males cannot be kept together. Day geckos feed on easily procurable insects but also require a fruit-honey mixture. Specialized watering methods are needed.
Origin and Life Span
The 60-plus species of day geckos are residents of Madagascar, the Comoro, Andaman and other Indian Ocean Islands and eastern Africa. Giant day geckos are very fast, and many have escaped from dealers to become established in the Miami area, as well as on the Hawaiian Islands. Longevity can exceed 10 years, and may near 20.
Adult giant day geckos are patterned with orange on a Kelly-green body color. Babies are darker in color than the adults. An ill or stressed day gecko may assume an unhealthy dark coloration. No aberrant colors have yet been established.
The eyes of the day geckos lack functional eyelids, the eye being protected instead by a transparent brille, such as those found in snakes. The lidless eyes are prominent but not overly large. The pupils are round.
Females are similar in appearance to males, except that they are slightly smaller, have a proportionately smaller head and smaller preanal pores. The toes are broadly flattened and provide non-slip footing on most horizontal and vertical surfaces.
To provide an escape mechanism, the bones of this gecko's tail are provided with fracture planes – weakened areas at which the tail can easily break free if grasped. The broken tailtip wriggles for several seconds – drawing the attention of a predator and allowing the gecko to escape. The gecko will re-grow (regenerate) a tail, but it is never quite similar in appearance to the original.
In the wild, giant day geckos establish home territories and defend them. Males allow females to enter their territory, but will skirmish with male interlopers. Males are particularly territorial during the breeding season and will spar incessantly. They advertise territorial dominance in easily audible vocalizations. Females form domination hierarchies, but generally do not squabble badly. Males usually get along well with females.
House only a single male per enclosure. In the terrarium, these lizards often station themselves in a head down position on the glass near the top of their terrarium or on vertical corkbark or bamboo.
Giant day geckos may move slowly but, if frightened, are very fast, agile, and are adept at escaping. As they move the geckos deliberately curl their toetips upwards to disengage the thousands of bristle-like setae that nestle in the lamellae (cross grooves on the underside of a gecko's toe). These setae enable the geckos to climb up even the smoothest of vertical surfaces.
If you move slowly, your day gecko will often allow close approach, but most will not allow themselves to be handled or otherwise touched. If carelessly grasped day geckos may bite.
A giant day gecko frequently cleans its brilles (eyecaps) by extending its tongue out of the side of its mouth and upwards. This will be done if beads of moisture or any other vision impairing impurities are present on the eyecap.
Provide your giant day gecko with the largest possible, well ventilated, terrarium. We suggest a minimum of a 29-gallon high terrarium for a pair or trio. A wire cage of similar size is equally good, better ventilated, will not allow a dangerous buildup of humidity, and will not, as a result of misting the terrarium, hold water on the bottom.
Provide your gecko with diagonal and horizontal limbs measuring the diameter of the lizard's body or larger. Additionally, give your gecko some corkbark hides. These, and vining plants, will help provide visual barriers and a feeling of security.
Full spectrum lighting is suggested for these heliothermic (sun-basking) diurnal lizards. The terrarium temperature should be maintained at 86 to 94 degrees Fahrenheit. If one end is slightly warmer than the other, and if hides are provided at both ends, your gecko will select the temperature most suitable for it. Nighttime temperatures can drop by a few degrees.
A substrate of leaves or finely shredded mulch (of some non-aromatic form) is fine.
The tank should misted once or twice a day sufficiently to create pendulous beads of water for your gecko to drink. This is the preferred way to provide water. It is important that you do not allow the tank to become saturated or to hold water as a result of the mistings.
These lizards are strongly omnivorous. They eat a wide variety of non-noxious insects (roaches, king mealworms, silkworms, crickets, waxworms) but captives should also be given a honey-fruit mixture. Baby day geckos will require insects of smaller size than the adults.
Fast growing babies and ovulating female day geckos should have periodic supplements of D3-calcium. Twice weekly supplementation is suggested while growth is rapid and eggshells are being formed. This can either be provided by dusting the insects with a vitamin-mineral supplement, or by incorporating the vitamins-and minerals into the fruit-honey mixture. Adult males should be provided vitamin-mineral supplementation about once every two weeks. It is possible to overdose these lizards with D3 and calcium. Use care.
The formula for the honey-fruit-vitamin mixture will often be eagerly lapped at. This consists of 1/3 pureed apricot baby food, 1/3 honey, 1/3 water, a few drops of Avitron liquid (bird) vitamins, and a level teaspoon of calcium-D3 powdered vitamins.
These geckos seldom drink from a dish unless the surface is roiled by an aquarium airstone attached to a small vibrator (or other) pump. Geckos prefer to drink the pendulous droplets when their cage is misted.
Giant day geckos are difficult lizards to handle safely – safely for them! These lizards do not like to be restrained. They will writhe in your grasp, often tearing their skin badly, and will become moderately stressed if restrained. The skin of all day geckos tears very easily.
Giant day geckos readily autotomize (break off) their tail. Do not grasp them by that appendage. It is best to move them by catching the gecko while it is on the glass in a soft fish net, then sliding a stiff piece of cardboard or plastic over the mouth of the net to prevent your gecko from escaping.
Common Diseases and Disorders
If properly fed, hydrated and handled, these giant day geckos are hardy and almost trouble free. Providing ample hydration may be somewhat of a challenge, but is really not difficult.
Because of their lifestyle, healthy feet and toes are of particular importance to these arboreal geckos. Be certain that the skin is shed from these during ecdysis.
Metabolic bone disease can occur if too little calcium is available or if available calcium is improperly metabolized. Calcium should be given in conjunction with vitamin D3.