Giant Day Gecko

Phelsuma grandis

Giant Day Gecko Care


Of all the day geckos, the giant (usually referred to as just ‘grandis’) is not only the biggest but is one of the most showy. Day active – as the name suggests – they are a bright, vivid green along the top side, marked with red spots and bars, with a pale underside and a yellow chin. They are bold, often darting to the front of their terrarium to watch what’s going on, and although they are a little too fast for safe handling, they are greedy enough to hand feed very soon after purchase.

Found across most of the northern part of Madagascar and all the offshore islands, they are very tolerant of disturbance and can be found in pristine rainforest, secondary growth forest, orchards, and even in gardens and on house walls and roofs. They have also been established in Florida and Hawaii, where their toughness and tolerance has enabled them to build up a thriving and stable population.

They are a large and robust species of gecko, with males reaching a maximum of 33cm in total length, although 25cm is more common with females a little smaller. They will happily coexist in male/female or female/female pairs, and make excellent terrarium subjects as long as their size is taken into account. For a single individual, a terrarium 45 x 45 x 60cm (18 x 18 x 24”) is the absolute minimum suitable, which should be increased to 60 x 45 x 60cm (24 x 18 x 24”) for a pair – although 60 x 45 x 90cm (24 x 18 x 36”) would be even better. These are true arboreal lizards that need more vertical space than horizontal, with lots of branches to climb on and hide behind. Bamboo tubes are very useful as decor, and are a favourite place for the females to lay their eggs.

As a diurnal, tropical species they like it warm and bright. Good strong UV light – compact bulbs are useless here – and a really bright hotspot are essential for long term maintenance of this species. Some owners use metal halide lighting, which does produce a very natural spectrum and has the power to punch down through lots of levels of foliage; however, these cannot be run on a thermostat, and are probably best left for the larger enclosures. A 5% UV tube is fine, provided that the basking spot is really bright – they do seem to respond very well to high light intensity.

Feeding is not at all difficult, as they are happy to take a range of suitably sized feeder insects. In the wild they will also eat nectar and overripe fruit, so honey is a great treat for them; there are also several complete food mixes specifically for day geckos, which work well. Be aware that some grandis are quite lazy – they love not having to chase their food, and easily become fat if allowed to gorge themselves on static meals.

Grandis are not suitable for handling, although they will quickly become tame enough to take food from the hand. Their skin is quite fragile, and will tear if they are held tightly; this is an adaptation to allow them to escape predators. They heal very quickly, but it’s not a pleasant experience for gecko or owner.

As a display species, the giant Madagascan day gecko is hard to beat. Big, bold, and wonderfully brightly coloured, they’re a little patch of rainforest that can brighten up your home!

Animal Information

  • Common name: Giant Madagascan Day Gecko
  • Scientific Name: Phelsuma grandis
  • Location: Northern Madagascar, offshore islands, introduced to Hawaiian islands and Florida
  • Habitat (wild): Tropical forest, scrub, urban areas
  • Captive environment: Tropical forest terrarium with plenty of climbing branches and hiding places.
  • Preferred temperature range: Daytime hot spot of 35ºC under the basking light, background ambient of 30ºc, cool end of 25ºc. Temperature can drop to 20ºc at night.
  • UVB Lighting: 5% or 7% UVB strip lamp, or 10% with plenty of leafy cover 
  • Ferguson Zone: Zone 3
  • Substrate: Soil/coir based
  • Lifespan: 10 to 12 years