Phelsuma madagascariensis grandis


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Phelsuma Madagascariensis Care Sheet


By: Dan Baker III

This document has been put together as an introduction of the natural history and captive care of Phelsuma madagascariensis grandis. Anyone interested in this species is encouraged to search multiple sources, as many keepers do not agree on all aspects of captive husbandry. I will refer to Phelsuma madagascariensis grandis throughout this document as "Grandis", "P.m. grandis" or Giant day gecko. This document is a collection of information I have gathered from numerous resources including several books, fellow breeders and personal experience.

Natural Habitat:

P.m. grandis can be found in various environments throughout their natural habitat. They can often be spotted basking on trees among various tropical vegetations, or tucked away in bamboo forests hidden throughout the foliage. As the amount of pristine habitat declines, the Grandis must continually adapt to their ever changing environment. They can be seen on many man made structures taking advantage of insect populations attracted by the humans.
P.m. grandis originate from a warm climate that receives heavy rainfalls regularly. These conditions sustain high humidity year round. Primary distribution of P.m. grandis is wide spread throughout northern and northwest Madagascar and a few nearby offshore islands. Small populations have been established in Hawaii and Florida due to unintentional introductions.


The Giant day gecko has successfully been kept in private collections around the world for numerous generations. These are a hearty species highly recommended for novice Phelsuma keepers with some reptile experience. This gecko is one of the largest Phelsuma species, with average growth reaching 10-12 inches when fully mature. Males are often larger then females with yellow coloration and large femoral pores under the thighs. Giant day geckos are primarily arboreal, meaning they inhabit trees in their natural environment.
These beautifully marked geckos are active during the day, often basking in plain site. The standard color for grandis is a vibrant green with some red coloring on the head and the back. A crimson line runs from each nostril to the eye but traditionally does not extend past the eye. Several variations in color are known, with the most sought after trait being the blue grandis which are very rare in private collections. Some owners prefer to selectively breed for more red in the patterns. These are some times sold as "Crimsons" while other breeders covet the nearly patternless specimen. Be aware that juvenile color schemes exhibiting high amounts of red will usually reduce during their growth.
The skin of the Giant day gecko is delicate compared to most geckos and can tear easily if handled improperly. This gecko’s skin consists of small granular scales. Torn skin will heal but most scars will remain throughout the gecko’s life. Regenerated scales are usually smaller then the original scales with a different shade of green. I have a female that lost a couple red spots on her back due to a male tearing the skin off and the regeneration was all green.

Captive care:


A well planted habitat can reduce stress and increase surface area for your geckos to explore. Recommended plants are sturdy and can handle high, relative humidity. Sansaveria, bromeliads, aroids and orchids are good examples. Bamboo that is situated under lights for basking is highly recommended as these geckos prefer smooth surfaces and heat variations to self regulate their temperatures.
Many different substrates, such as Coconut Shred cypress mulch and orchid soil, have been used successfully with this species. Depending if your substrate is used for live plants or otherwise, I recommend any plant soil with the small Styrofoam balls should be covered with coco bark or Sphagnum moss to reduce the risk of your gecko ingesting it. I use paper towels as a substrate and place potted plants in my tanks. I find this much easier to maintain and since the geckos are primarily arboreal they are seldom found on the substrate.
Bright light, high humidity and plenty of ventilation will benefit your animals as well as your plants. I have been getting great results utilizing tall glass enclosures with screen lids. Lights used for day geckos are often a topic of much debate. Within my collection there is no debate about lighting. I use dual fluorescent 48 inch bulbs that run across the tops of my tanks. One bulb is a PHILIPS TL 950 - T8, 5000 Kelvin, 98 CRI "Full Spectrum" Fluorescent Lamp and the second is a Repti Sun 8.0 that is replaced once a year.
I do not use any basking lamps as my room temperature remains in the low eighties and heat is also provided by heat tape fixed to the back of all my tanks. Bamboo should be positioned horizontally near the top of the tank allowing the maximum benefit from the U.V. bulbs. However, basking spots under the fluorescent lights sustain temps in the low 90's during the day. When the lights turn off, my night temps drop about 10F but never drop below 70F.
These animals like to drink droplets of waters from leaves and from the glass of the terrarium. Misting the tank twice daily with water facilitates enough humidity and liquid for drinking. Adults are not as sensitive to low humidity as the juveniles of this species. While humidity often drops in my adult cages between misting to around 30%, I have experienced no adverse health issues as long as proper hydration is achieved.
If your gecko is having trouble sloughing their shed, my advice is to place them in a humidity box. A humidity box can be as simple as a 2 1/2 gallon tank with moistened moss at the bottom and a heat source that keeps temperatures around 85F. Cover 3/4 of the lid so the humidity remains high but allows enough ventilation for creature comfort. You can also place a piece of wood in the box as the geckos often rub their nose against a rough surface to start the shedding process.
Hatchlings should be kept at a minimum of 50% humidity until they have reached approx 6 months in age, as they dehydrate much easier then adults. I bring my geckos into natural sunlight often for short periods of time in screen enclosures. No longer then 10 minutes on a warm day is recommended especially with smaller geckos that can dehydrate quickly. It is best to leave half of the screened enclosure shaded so the gecko can escape the sun if temperatures are too warm. Mist the container thoroughly to ensure your gecko is well hydrated during their adventure outdoors. I try to bring my juveniles and pregnant females out doors once a week if weather is above 70F. Although this is not required care the geckos definitely benefit from sunlight in small doses. Always keep in mind that regardless of advanced lighting technologies, no light bulbs replicate the far superior rays of the sun. Sunlight is especially effective when a gecko is in poor health, pregnant or a juvenile. As my good friend Joe Farah says, "Direct sunlight is the breast milk of baby Phelsuma." Captive techniques have been refined through several experienced keepers documenting all aspects of husbandry. Further details on keeping can be found in book form or on the internet.


Crickets, along with pureed fruit and tropical baby foods, are the primary food source that I use for my grandis. I often add supplements to fruit baby food to provide their required vitamins and minerals. I use Rep-Cal ultra fine calcium with vit.d3 and Herptivite as my multivitamin adding calcium to the baby food at every feeding and dusting my insects with a 1 to 1 calcium/multivitamin mixture once a week. Any calcium or multivitamin should contain only small amounts of vitamin A as an excess of this vitamin can hinder calcium absorption. In my experience, mixing the baby food with water and a bit of honey to thicken the mixture reduces molding better then plain baby food.
Fruit mixtures should be replaced every third day for adults and every other day for juveniles, unless the food dries up or molds before that time. I serve my adult gecko’s baby food in Gatorade caps or similar sized lids. Juveniles are fed only a couple drops of baby food per feeding as they frequently step in the mixture and consequently stick to everything. I alternate fruit flies or small crickets every other day for juveniles. In my opinion, optimal growth is achieved when a nutritious food substance is always available. If your food is drying out too quickly, move the food to a cooler portion of the tank and mist the food twice a day to retain moisture. Clark’s diet is enjoyed by all of my fruit eating geckos and is convenient as well as nutritious. Many other food sources are accepted by grandis such as soft bodied insects you can catch almost anywhere.
A few examples of feeders I have used are grasshoppers, moths, pill bugs, cockroaches, mealworms, pinkies, tomato worms, small lizards, house flies, wax worms, and earth worms; just to mention a few. The point is: The Grandis will accept most critters they can fit in to their mouths and should be given a variety of substances for optimal health. Gut loading of all insects will also insure ideal health. Foods like crickets should be fed fresh vegetables such as lettuce and carrots to pass on the partially digested vitamins and other good nutrients to your gecko.

Reproductive behavior:


If breeding P.m.grandis is your ultimate goal, here are some basic requirements and personal observations that should assist your success. I have kept 3 females and one male that rotated from tank to tank and produced many eggs. Aggression was a problem for me, but I attribute this to my male being almost an inch larger then my smallest female. The male’s can be recognized by their enlarged femoral pores shown in the picture above. Many breeders suggest they limit aggression by keeping 1 male and 1 female together and do not separate them, as a re introduction can often lead to aggression. Currently I keep one male and two females all in separate tanks.
I introduce the male to the female’s tank a couple days after she has dropped her first clutch of unfertilized eggs. After she drops the "slugs" it is best provide the female with plenty of food and dusted crickets to regain the calcium reserves lost during egg dropping. I also mist one extra time to ensure she is not getting dehydrated. These infertile eggs will not have a hard outer shell and often appear yellow in coloration. Females are known to eat their unfertilized eggs so that the calcium is reabsorbed into the gecko for later egg production. I transfer my geckos by holding a piece of clear plexi glass on the inside of the gecko tank and coaxing the gecko onto the plexi then transferring to the mate's tank. The male is added to the female’s tank giving her the "home court advantage". If your female is more aggressive then the male, it is recommended that you try introducing the female to the male's tank.
A vertically oriented, well planted terrarium, with plenty of visual barriers, is a great way to reduce aggression with introduced pairs. In my opinion you should not breed a female that is under a year old, as the loss of body weight and calcium can be taxing to their growth and overall health. Shortly after introduction, a number of interactions occur that will determine whether the female is receptive to mating. Tongue flicking and head bobbing from side to side occurs almost immediately accompanied by short vocalizations by both when the male is introduced. The male and female will move their tails like an "S" during courting rituals.
The male will move around the female until she is positioned underneath him. The male will then grab the side of the female’s neck, usually directly on the visible calcium sacks, while positioning his body on top of the female. The male will move his foot beneath the female and lift her hind quarters, up positioning himself directly against her vent. Then copulation occurs that appears rather contorted as the male often remains holding the females neck until completion. After a couple of minutes the male will release the female and she will usually scamper off and the male will clean his hemi penis for a short time.
If the female is not receptive, she will usually lift her front feet one at a time while flicking her tongue. Should this take place, remove the female so aggression does not occur. Females that are unreceptive will often be treated by a male as a rival and injuries are common if left together. Signs of eggs will show in about three weeks. A couple of days before eggs are dropped the female will usually refuse food. Prior to laying, the female will darken in color and position herself facing up in her chosen egg laying site. This position can look very awkward as the female is supported by her front legs and tail. This frees the females back legs to receive the eggs. She will drop one egg at a time and shape it until it hardens which can take as much as an hour. Then the female will drop the second egg and attach it to the first. The female will continue to shape both eggs until they harden. This can take more then an hour. When she is confident that both eggs have hardened, she will leave them, often for a drink.
I will then remove the eggs and place them in a 2 liter cap with unmoistened vermiculite. This prevents the eggs from rolling around in the incubator. Then I place the cap in a low deli cup half filled with vermiculite and water in a 1 to 1 ratio. I cut a square hole (large as possible) in the top of the deli cup lid. Then I cut a piece of screen that will cover the new hole. I use tape on the outside of the lid to secure the screen. This provides enough air flow and prevents moisture from collecting on the lid and soaking the eggs .I keep each clutch of eggs in separate deli cups as hatchlings will inadvertently move the unhatched eggs if allowed.
I incubate the eggs in a basic hova-bator and my temps are currently kept around 82F with a slight temperature drop in the evenings. Incubation temperatures in the low 80’s will produce more females and temperatures retained around 88F will produce more males. Many breeders report if temps are kept at 86-87F, a good female to male ratio is achieved. I have not raised any of my offspring to maturity, so I can not confirm this data. Humidity for the eggs should remain above 70% through the incubation. Average Humidity in my incubator is 80-95%. Ventilation is also paramount to prevent molding of the eggs. Grandis eggs do not require darkness to develop properly.
Eggs will usually hatch between 48 and 58 days. Higher temps will reduce incubation time while lower temps promote slower development. Juvenile Grandis will slough their skin shortly after emerging from their egg. I keep juveniles in tall deli cups with the same screen lids I use for the incubator cups. I set these directly under fluorescent lights and mist twice daily. Paper towel is used as the substrate and 2 holes are drilled near the top where bamboo skewers are positioned to provide a basking spot. I usually place a clipping of Sansaveria inside the tank as cover and easy access to the basking area.


Grandis continue to be one of the more popular Phelsuma due to their relatively easy care and stunning appearance. In raising these magnificent animals I have gained an incredible amount of information and am left with many more questions. Records with details of your triumphs and failures are integral to the science of success. Our knowledge is the greatest gift we can offer. I hope this care sheet will assist in raising these jewels from Madagascar.
Dan Baker III