Giant day geckos (Phelsuma grandis) are large, vividly colored geckos endemic to Northern Madagascar.
Like all Madagascan day geckos, giant day geckos are highly active, arboreal lizards. Reptile keepers prize them because of their stunning coloration.
Unlike other geckos – such as the leopard gecko – giant day geckos are NOT recommended for beginners.
They have a long list of care requirements. They’re also quick, delicate, and skittish lizards- making them difficult to handle safely.
If you’re an intermediate or experienced keeper seeking a beautiful display animal, look no further than the giant day gecko.
If you’re new to exotic animal husbandry – or prefer to handle your pets – you may wish to consider another species.
The White’s tree frog is a stunning amphibian with similar, vivid coloration that also works well as a centerpiece for display.
Table of Contents
What You’ll Learn
In this article, you’ll learn:
- Background information about the giant day gecko
- How and where to buy a healthy gecko (responsibly)
- How to create the perfect giant day gecko enclosure
- What you should feed your giant day gecko – and how often
- Regular maintenance and how often to clean your enclosure
- Information about giant day gecko breeding and reproduction
- Information about species-specific health problems (symptoms, causes, and treatments)
Giant Day Gecko Background Information
Giant day geckos are one of many day gecko (Phelsuma) species native to the island of Madagascar.
As their name suggests, they’re the largest living species of the genus Phelsuma.
Many reptile enthusiasts consider them to be amongst the most beautiful lizards.
In this section, you’ll learn some background information about the giant day gecko (Phelsuma grandis) in the wild and how they behave in their natural habitat.
We’ll also discuss the giant day gecko as an invasive species and its conservation in Madagascar.
Giant day geckos reach lengths of around 12 inches (including tail).
They’re among the most charismatic of all reptiles, with large, bulbous eyes, sticky toe pads, and a somewhat “cheery” expression.
They’re typically bright green with red markings and a yellow or off-white underside.
The red markings of a giant day gecko tend to lessen with age.
They can also vary significantly between individuals. This variability is part of what makes them such desirable display animals.
You can find a gallery of available morphs here.
Day geckos can also change color based on their mood. Dark green coloration is a valuable indicator that a giant day gecko is under stress.
Habitat and Ecology
Giant day geckos are adapted for life in the tropical and subtropical forests of Madagascar.
They’re also a highly arboreal species, rarely descending from the forest canopy.
As their name indicates, giant day geckos are diurnal. They’re most active during the day.
These lizards live for an average of 6-8 years in captivity.
As an Invasive Species
The giant day gecko is considered an invasive species in Hawaii, Florida, Mauritius, and Réunion.
Recent scientific evidence suggests that giant day geckos may be responsible for a decline in native Mauritian gecko populations.
Phelsuma grandis is currently listed as a species of “Least Concern” in the IUCN Red List of endangered species.
Current population trends (increasing, stable, or in decline) are not currently known due to insufficient data on the subject.
Due to its relatively small geographic range, this species could be vulnerable to overexploitation and habitat loss.
Many other day gecko species are now endangered or in decline.
Thankfully, the giant day gecko’s range is currently protected.
The species is also listed in CITES Appendix II, meaning that a permit is required to export specimens.
However, the trapping of wild specimens is still considered to be a threat to this species.
Buying a Healthy Giant Day Gecko
When purchasing a gecko, look for signs of health such as:
- Round, fat tail
- Bright, responsive eyes
- Overall alertness and activity
- Healthy, colorful skin (without wounds or lesions)
Avoid purchasing animals kept in overcrowded or dirty conditions, or if any other animals in the tank show signs of disease.
As little information exists regarding their conservation status in the wild, it’s vital to be a responsible consumer when purchasing a giant day gecko.
Avoid wild-caught animals at all costs.
All captive-bred individuals are – of course – descended from wild-caught animals.
Thankfully, captive-bred day geckos are now commonplace.
There are many reasons to avoid supporting the import of wild specimens, such as:
- As reptile lovers, we all want to protect these animals. Removal of wild animals for the pet trade harms native populations, driving them closer to extinction.
- Wild-caught animals can harbor diseases and parasites. These pests can be hazardous to your other animals.
- Wild animals are also far less likely to take to handling and are usually more skittish than captive-bred.
Purchasing directly from a breeder is the best way to make sure that your animals have been captive-bred.
Expert Tip: Adults are more likely to be wild-caught, so purchase younger animals wherever possible.
Breeders are more likely to provide accurate care information than other sources.
They’re also usually willing to stay in touch and answer your questions.
Another advantage is that breeders may know an exotic animal veterinarian in your area. This resource could come in handy later on.
Giant Day Gecko Diet
Giant day geckos are omnivores and are highly opportunistic in the wild.
As a result, they’re rarely fussy eaters. A diverse and healthy diet is easy to implement.
In captivity, they do well when offered a variety of feeder insects and plant-based options.
Live, gut-loaded feeder insects should make up the majority of your gecko’s diet.
Insects are rich in protein. They also contain fiber to aid digestion.
Gut-loading is a term for feeding a specially formulated, nutrient-rich feed to your insects.
This practice makes them a better source of food for your day gecko.
Insects should be gut-loaded 24 to 48 hours before being placed in your lizard’s enclosure.
Select feeder insects based on nutritional contents.
Crickets – either brown, black, or banded – can make up most of the insect matter in your gecko’s diet.
Size-appropriate roaches (such as medium-sized dubia roaches), grasshoppers, and soldier fly larvae are excellent choices.
Some insects – particularly most beetle larvae – can be high in fat. Offer fatty foods like mealworms and waxworms only as occasional treats.
An excess of fat can lead to obesity and cause a range of health problems.
An entirely plant-based diet is insufficient for day geckos and may lead to obesity and malnutrition.
Still, plant-based foods should make up around half of your day gecko’s diet.
Wild tokay geckos will often lap up nectar and pollen from flowers in the wild.
Nectar provides lizards with an energy boost, whereas pollen is rich in vitamins and minerals.
A variety of dietary mixes have been formulated for herbivorous and frugivorous reptiles.
These can be an excellent way to supply the plant-based portion of your gecko’s diet.
For captive geckos, fruit is a more accessible alternative to nectar that is also high in sugar.
Some keepers use mashed fruits or baby foods as a treat for their geckos.
Tropical fruits such as pineapple, mango, or cantaloupe are typically good choices.
Note that fresh fruit can cause obesity in large quantities.
Vegetables and leafy greens contain much of the same nutrients as pollen and are far easier to come by.
Pumpkins, squash, mushrooms, bell peppers, and prickly pear leaves all make excellent choices for vegetables.
Escarole, dandelion leaves, and alfalfa are among the best leafy greens.
Expert tip: It is easy to create a veggie mix, and geckos are more likely to eat fruit and vegetables in a puréed form. Just ensure that your mixture isn’t too high in sugar.
It would be nigh on impossible to replicate the diverse diet of a day gecko in captivity.
Instead, captive geckos require supplementation on top of their regular diet.
Supplementing will allow you to provide them with the specific nutrients lacking from insects and other foods.
Supplementation involves dusting and gut-loading.
There are several good nutritional mixes available in reptile stores. Ideally, choose a mixture that contains the following nutrients:
- Vitamin A
On top of this, dust all feeder insects with plenty of calcium powder before feeding.
For an excellent breakdown of the nutritional needs of Phelsuma species, check out this handy food pyramid.
Geckos will lap moisture from vegetation and vivarium surfaces. Mist your vivarium daily to provide plenty of water.
As a backup, you should always provide a shallow water bowl for your animals.
Day geckos are diurnal. They prefer to eat in the morning.
The amount you need to feed your geckos varies based on their age and reproductive status.
Offer adults insects around twice per week.
Full-sized adults will comfortably eat around three to five crickets per meal.
Dust feeder insects with calcium before serving. Use a multivitamin supplement once per week.
You should also offer your geckos a portion of your chosen plant-based mix around once per week.
Juveniles and Breeding Females
Juvenile giant day geckos (and breeding females) require a greater energy supply. Feed them between five and seven times per week.
Creating the Perfect Giant Day Gecko Enclosure
Tank Size and Shape
A glass or plastic enclosure with a screen lid is best for housing giant day geckos.
Avoid wooden enclosures, as they can house harmful bacteria and fungi in humid conditions.
These geckos are highly arboreal and will utilize vertical space in their enclosure for climbing. Your gecko’s enclosure should be taller than it is wide.
As for size, a 25-gallon vivarium will comfortably house one gecko or a pair.
Giant day geckos require a substrate suited to a humid environment.
Choosing an appropriate substrate is essential to maintain consistent humidity levels and to prevent mold.
Excellent choices for this species include rainforest soil mixes (with fine particles), shredded coconut husk, orchid bark, and cypress mulch.
Many keepers opt for a combination of one or two substrates with desirable properties.
Using a bioactive substrate with a drainage layer can help to reduce waste buildup. It may also help to increase humidity.
A layer of sheet moss or (disinfected) leaf litter can also aid in humidity maintenance and add a natural feel to a planted vivarium.
Ensure that substrate particles or mosses are large enough to prevent being ingested by your gecko.
It’s common for reptiles to accidentally eat small particulate matter while feeding. Substrate ingestion can cause impaction.
Decorations and Enrichment
These lizards require a diverse environment with plenty of structures to climb and explore.
Most keepers of day geckos opt for a natural-looking, planted vivarium to mimic the species’ natural forest habitat.
It’s pretty easy to create a stunning enclosure for this species.
Include plenty of the following options to keep your geckos happy:
- Sturdy branches
- Mounted cork bark/tunnels
- Sturdy plants (live or artificial)
Branches or hardwood decorations must be suitable for high humidity levels. For this reason, avoid grape wood.
Ghostwood, cork, and bamboo are excellent choices for day gecko enclosures.
Affix plants to wooden objects (or drape them over the top) to offer areas for your geckos to shelter.
Artificial plants are a low-maintenance option, but reptile-safe live plants are unmatched in terms of appearance.
In either case, these large geckos do require sturdy plants that can withstand their weight.
You may also wish to add a backdrop as a final touch to your naturalistic vivarium.
Check out some of our favorite vivarium backdrops if you need inspiration.
Lighting and Temperature
As a tropical/subtropical, diurnal species, day geckos do have specific lighting and temperature requirements.
They also require a consistent 12-hour day/night cycle.
They’ll need an overall daytime temperature between 28 and 30°C (82 to 86°F).
Lower this temperature to between 24 and 28°C (75 to 82°F) at night.
Provide a basking area – between 29 and 32°C (85-90°F) using a reptile-safe incandescent bulb.
Your geckos will use this area to thermoregulate and receive plenty of UVB for vitamin synthesis.
Some keepers living in tropical or subtropical climates choose to keep their geckos in a fine mesh cage outside.
Natural sunlight will provide enough UVB for your geckos, but ensure that they have access to shade to prevent overexposure.
Expert tip: Glass or plastic enclosures can quickly overheat in the sun. Never place a glass or plastic vivarium outdoors.
These geckos require an ambient humidity level between 50 and 70% at all times.
Mist your vivarium and substrate daily to keep humidity levels within this range.
If you find that your vivarium humidity is still too low, there are some additional steps you can try, such as:
- Using an automated misting system
- Adding live plants to your vivarium setup
- Using a bioactive substrate that retains moisture well
Excessive humidity will lead to a buildup of bacteria and fungi, which can lead to respiratory problems.
Low humidity can cause shedding difficulties.
Monitor your vivarium humidity regularly using a hygrometer.
Keeping Giant Day Geckos in Groups
As with other geckos, keepers should never house adult males together. Day geckos are highly territorial animals and will fight viciously.
These lizards do well alone or in male-female or female-female pairs.
Regular Enclosure Maintenance
Check the temperature and humidity of your enclosure regularly.
Spot clean your enclosure daily to remove any feces. Check the substrate, walls, and decor.
Replace water daily. Replace water immediately if soiled with feces or dead insects.
Once per month, wipe the walls of your vivarium with a reptile-safe cleaner (or a dilute white vinegar solution).
Perform a complete substrate change every three to four months.
Giant Day Gecko Health Concerns
As a general rule, giant day geckos are hardier than other day gecko species.
Still, there are a couple of crucial issues to be aware of.
Most issues are easily preventable with proper husbandry and a consistent cleaning schedule.
Keepers of giant day geckos commonly report shedding issues. Thankfully, they’re easy to prevent.
- Skin infections
- Low humidity (below 50%)
- Dead skin remains stuck to your lizard after shedding is complete
- Spray your gecko with water to help loosen the skin.
- Attempt to gently free the skin using tweezers. Never attempt to forcibly remove dead skin, as this can cause damage to the new skin underneath.
- If this technique is unsuccessful, consult a vet.
- Provide a balanced diet with supplements
- Maintain consistent humidity levels within the range of 50 to 70%
Metabolic Bone Disease
Metabolic bone disease can develop in any lizard species.
- Calcium or D3 deficiency
- Poor appetite
- Difficulty moving
- Over-the-counter supplements (mild cases)
- Prescription medication to boost bone repair (severe cases)
- Consult your vet for advice before attempting to treat MBD.
- Provide multivitamins once per week
- Provide calcium supplements with every meal
- Ensure your lizard has access to sunlight or a basking area for UVB
Day geckos are oviparous, meaning that they lay eggs. Females can lay multiple clutches during each breeding season.
Male and female pairs will likely mate and produce offspring if housed together. You’ll need to incubate the eggs in order for them to hatch.
Ensure that the orientation of eggs remains the same, or embryos may suffocate. Gently marking the upper surface with a pencil will simplify things.
Be sure that you’re ready to deal with this commitment before housing males and females together!
Handling Your Giant Day Gecko
Giant day geckos are NOT well suited to handling.
They’re delicate animals and can move rapidly when they feel threatened.
This combination makes it easy to accidentally harm your gecko during handling.
With careful desensitization, you may find that you can hand-feed your day geckos.
Following this, they may learn to tolerate gentle, occasional handling over time.
Day geckos are a poor choice for keepers looking to handle their pets.
These are among the most tolerant and handleable of all lizard species.