Fellow Creatures
Pet match quiz
Madagascar Giant Day Gecko
Reptiles · Geckos

Madagascar Giant Day Gecko

Phelsuma grandis

Brilliant green, diurnal, strictly hands-offIntermediate

Lifespan
10-15 years
Size
10-12 in
Social needs
Solitary; house singly
Time
Medium; feed every 2-3 days, daily misting, lighting
Cost
High
Diet
Omnivore (insects + nectar/fruit)

Overview

What is this animal?

  • The Madagascar giant day gecko is a large, vivid emerald-green, diurnal gecko from northern Madagascar, often marked with red flecks.
  • Unlike most pet geckos it is active and brightly coloured in daylight, which makes it a striking display animal, but it is a look-don't-touch species with delicate, tear-prone skin.
  • It is more demanding than the nocturnal beginner geckos because it genuinely needs strong UVB, a basking gradient and high humidity.
  • It suits keepers who want a planted vivarium to observe rather than a gecko to handle, and rewards good husbandry with bold, interesting behaviour.

Temperament

  • Day geckos are fast, alert and largely hands-off; they stress easily when handled and their delicate skin can be injured by restraint, so they are best enjoyed as an active display species.
  • They are diurnal, so unlike most geckos they are at their most visible during the day.
Show 3 more
  • They are territorial and must be housed singly outside of supervised, carefully managed breeding.
  • Two adults, especially males, will fight fiercely.
  • A single gecko in a well-planted vivarium is the correct, welfare-friendly setup.

A good fit for

  • Keepers wanting a vivid display gecko
  • Hobbyists who enjoy planted bioactive vivariums
  • Those happy not to handle their reptile
  • People who can provide strong UVB and humidity

Common mistakes to avoid

  • Handling that tears their fragile skin
  • Inadequate UVB and calcium
  • Housing two together (serious fights)
  • Humidity too low or stagnant and mouldy

Enclosure

Minimum 11 sq ft of floor · 39 x 39 x 59 in

Must be housed alone. Solitary; house singly

  • Provide a tall, well-planted vivarium of at least 39 x 39 x 59 in for one adult, usually built to order, furnished with bamboo, broad-leaved live plants and cork for climbing and basking.
  • As an arboreal, diurnal species it needs both vertical space and bright lighting, so a bioactive planted setup suits it well.
  • Maintain a basking spot of around 86-90°F with a cooler ambient of 75-79°F, and provide a moderate-to-high output UVB tube, which is essential for this sun-loving lizard.
  • Keep humidity around 60-80% by misting once or twice daily, allowing partial drying between mistings to prevent stagnant, mouldy conditions.

Check your enclosure

Supplies

Setup

  • Custom-built enclosure, 39 x 39 x 59 in
  • Heating and thermostat
  • T5 high-output UVB fixture and bulb
  • Thermometers and hygrometer
  • Substrate, live plants, branches and decor

Ongoing

  • Complete powdered fruit-gecko or day-gecko nectar diet (for cresteds, gargoyles, chahouas, mourning and day geckos; not for leopard, fat-tailed or tokay geckos)
  • Live crickets, dubia roaches or black soldier fly larvae
  • Plain calcium powder without D3
  • Calcium with D3 plus a reptile multivitamin
  • Feeder gut-load and a ventilated feeder tub
Show 3 more
  • Shallow ledge-mounted feeding cups (fruit-eating geckos)
  • Blunt-tipped feeding tongs
  • Shallow water dish

Safe substrate: Topsoil and play sand mix for arid geckos · Coco fibre and orchid bark for tropical geckos · Paper towel

Work out the cost

Care routine

Daily

  • Check temperatures and humidity
  • Fresh water bowl
  • Look the animal over
  • Mist the enclosure
  • Spot-clean waste and uneaten food
Show 9 more

Every few days

  • Check toes, tail tip and eyes after a shedevery 3 days
  • Feed dusted live insects (adults two or three times a week; juveniles under six months daily)every 3 days
  • Quiet observation session (no handling)every 3 days

Weekly

  • Offer a complete gecko diet or nectar (adults once a week; juveniles every other day)

Every few weeks

  • Weigh-inevery 2 weeks

Monthly

  • Deep-clean decor, glass and bowls
  • Test thermostats, lamps and guards

Less often

  • Refresh the substrateevery 3 months
  • Check the UVB lamp's age and replace it if due (if one is fitted)every 6 months

Vet: Annual exam and faecal check, every 12 months (every 6 months from 10 years old)

Tools

Is your enclosure big enough?Check your measurements against the recommended sizeWhat will it cost?Setup, monthly and over its whole life, itemisedCan it eat that?Search 22 foods, from everyday to never

Care in depth

Diet

Omnivore (insects + nectar/fruit)
  • Day geckos are omnivores.
  • Feed gut-loaded, calcium-dusted live insects such as crickets, dubia roaches and locusts, sized no larger than the space between the eyes: daily for juveniles under about six months, then two or three times a week.
  • Alongside insects, offer a complete gecko diet (a crested-gecko-style fruit diet) or a commercial day-gecko nectar to mimic the pollen, nectar and soft fruit they take in the wild: every other day for juveniles and once a week for adults, as ReptiFiles schedules it.
  • Supplement with calcium and vitamin D3 on a regular schedule to support their fast metabolism and coloration.
  • Provide fresh water, though they mostly lap droplets from misted leaves.
  • A varied insect-and-nectar diet prevents the deficiencies seen on insects alone.

Health

Signs of good health, and the common problems
  • Healthy day geckos are vividly coloured, alert and quick, with clear eyes and a good appetite.
  • Their skin is fragile and tears easily, sometimes leaving permanent scars, so they should be handled as little as possible.
  • Calcium deposits, metabolic bone disease from poor UVB or supplementation, and retained shed are the main concerns.
  • Dull colour, lethargy, weight loss or a swollen jaw signals a problem and warrants a vet experienced with exotics.
  • Because they bask in strong light, correct UVB and a proper thermal gradient are central to preventing the most common illnesses.

Is this urgent?

4 warning signs and how fast to act, 1 of them right away

Small geckos dehydrate and lose condition quickly. Weight is the fuel gauge, and in leopard and African fat-tailed geckos so is the tail.

Go now

Tremors, weak grip, or a jaw that will not close properlyGo now. Calcium and D3 deficiency.
Now

Today

Tail visibly thinning in a species that stores fat thereWeigh, then call with the trend. The fat store goes before the body condition does.
Today
Stuck shed around the toes or over the eyesRaise humidity, offer a damp hide, and call if it is not clear within a day. Constricting shed rings cost toes. This is the most common avoidable injury in geckos.
Today
Refusing food with weight lossCheck the cool-end and warm-end temperatures, then call. A gecko that cannot reach its preferred temperature cannot digest.
Today

This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it, and the time to find one is before you need one.

Bedding and substrate

3 safe, 1 with a caveat, 3 to avoid

Match the substrate to the species' humidity, and never let a small gecko stand on anything it can swallow whole.

Safe

Topsoil and play sand mix for arid geckosPacks firm, holds a burrow, and is what a leopard gecko would actually stand on.
safe
Coco fibre and orchid bark for tropical geckosHolds the humidity a crested or day gecko needs.
safe
Paper towelCorrect for quarantine, for hatchlings, and for any animal whose output you are watching.
safe

With a caveat

Sphagnum mossExcellent in a humid hide, poor as a whole-floor substrate: it stays wet.
with a caveat

Never

Calcium sandSold as digestible, which is exactly why it gets eaten. Implicated in impaction.
never
Crushed walnut shellSharp and indigestible.
never
Loose play sand alone for hatchlingsToo easy to swallow at that size.
never

Ground-dwelling geckos such as leopard and fat-tailed geckos need a humid hide whatever the main substrate is, and most of their stuck sheds trace back to its absence. Arboreal geckos get their shedding humidity from misting the whole enclosure, so stuck shed in them usually means the enclosure is too dry.

Top resources for more info

Independent creators and organisations we would send a friend to. We have no affiliation with any of them, and nothing here is sponsored. Links checked 2026-10-22.

YouTubers

Reptiles and ResearchEvidence-led husbandry: enclosure size, UVB, thermal gradients, enrichmentClint's ReptilesWhich reptile suits you, with honest care and handling verdictsGoHerpingBeginner reptile care, setup mistakes and welfare basics

Sites

Keep going

Geckos, side by side

Same axes, same care guides: the honest way to choose between types.

See all Geckos side by side →Compare with other animals

More Reptiles guides

Leopard Gecko
Eublepharis macularius
Beginner

Ground-dwelling desert gecko with eyelids

15-20 yearsRead guide →
Crested Gecko
Correlophus ciliatus
Beginner

Arboreal gecko with fringed eye crests

15-20 yearsRead guide →
Gargoyle Gecko
Rhacodactylus auriculatus
Beginner

Bumpy-headed gecko that regrows its tail

15-20 yearsRead guide →
African Fat-tailed Gecko
Hemitheconyx caudicinctus
Beginner

Mellow ground gecko that likes humidity

15-20 yearsRead guide →
Tokay Gecko
Gekko gecko
Advanced

Large, vocal, defensive display gecko

10-20 yearsRead guide →
Bearded Dragon
Pogona vitticeps
Intermediate

Diurnal lizard with high heat and UVB needs

10-15 yearsRead guide →

Is your enclosure big enough?

These are the smallest sizes that give good conditions, not legal minimums. More room is always better.

Minimum 11 sq ft of floor · 39 x 39 x 59 in

Every figure, and where it comes from

Giant day geckos climb and bask high up, so this is a tall planted vivarium. Few are sold in this size, so most are built to order.

Minimum floor area11 sq ft of continuous, unbroken floor
As dimensions39 x 39 x 59 in
Height59 in minimum. This species climbs, so height is not optional.
CompanyMust be housed alone. Solitary; house singly
The recognised standards do not agree on this one
Swiss Animal Protection STS: 39 x 39 x 59 in for one or two giant day geckos. The figure this site uses: its recommendation for an animal-friendly enclosure. Checked 2026-10-23.
ReptiFiles: 24 x 24 x 48 in for one, larger strongly recommended. A minimum, below Swiss law for this gecko. Checked 2026-10-23.
Switzerland, Tierschutzverordnung (legal minimum): 6 x 6 head-body lengths of floor and 8 of height for one or two: 35 x 35 x 47 in at a 6-inch head-body length. A legal minimum, recorded for context. It applies to a single gecko too; the figure used here meets it up to about 6.5 in head-body length. Checked 2026-10-23.
Austria, 2. Tierhaltungsverordnung (legal minimum): 5.5 sq ft of floor and 31 in of height for one or two adults of Phelsuma madagascariensis, the species the giant day gecko was once classed under. A legal minimum, recorded for context. Below the figure used here. Checked 2026-10-23.

What it really costs

Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.

Can a Madagascar Giant Day Gecko eat that?

Day geckos are omnivores: live insects two or three times a week, plus a complete gecko diet or nectar once a week. Juveniles take insects daily and the gecko diet every other day.

The full list: 22 foods

Never (13)

AlcoholNo safe amount at any body weight on this site.
never
AvocadoPersin.
never
CaffeineCoffee, tea and energy drinks. Cardiac and neurological toxicity at tiny doses for an animal this size.
never
ChocolateTheobromine and caffeine. Small mammals and reptiles cannot clear either.
never
CitrusAcidic enough to upset the gut, and sugary. Not worth the risk.
never
FirefliesLucibufagins. Fatal to geckos.
never
GarlicSame allium toxicity as onion, and more concentrated by weight.
never
Insects larger than the gap between the eyesA recognised cause of impaction and neurological injury in small geckos. Size the feeder to the animal, every time.
never
LeekAllium family. Same mechanism as onion and garlic.
never
OnionOrganosulphur compounds damage red blood cells. The whole allium family is out.
never
RhubarbVery high in soluble oxalate, high enough to cause acute kidney injury. The leaves are worse than the stalks.
never
Salty or seasoned human foodSalt, oil and seasoning. Crisps, chips, seasoned leftovers and processed meat are all out.
never
Wild-caught insectsPesticides and parasites.
never

Rare treats (1)

WaxwormsVery fatty and habit-forming. Useful to get weight on a thin animal. One or two, rarely.
rare treat

Occasional (5)

Complete crested gecko diet powderA day-gecko nectar or a fruit-gecko diet, alongside insects, mimics the pollen, nectar and soft fruit day geckos take in the wild. Once a week for adults; every other day for juveniles under about six months.
occasional
HornwormsHigh water content; useful for a dehydrated animal. One occasionally.
occasional
Mashed fruitA little soft fruit, as a supplement to the nectar diet and insects, never instead of them. A small amount, occasionally.
occasional
MealwormsHard chitin and a poor calcium ratio. A gecko fed only mealworms is heading for calcium problems. A few alongside better feeders.
occasional
SuperwormsFatty. One or two.
occasional

Everyday foods (3)

Black soldier fly larvaeHigh in calcium, and readily taken. Several per feed.
everyday food
CricketsStandard feeder. Gut-load for 24 hours before offering. Sized to the eye gap.
everyday food
Dubia roachesThe best routine feeder for insectivorous geckos. Sized no wider than the space between the eyes.
everyday food

That food is not on our list. Check which kind of gecko you have first (the two diets barely overlap), then ask an exotics vet.

Supplement with calcium and vitamin D3 on a regular schedule to support a fast metabolism.