The halmahera gecko (Gehyra marginata) is an 11-12” long, crepuscular, arboreal lizard native to the Indonesian island of Merauke. They live in tropical rainforests as well as rural human dwellings. This species is also known as the “halmahera giant gecko” and the “ternate dtella”.
Halmahera geckos have a rounded snout, round lidless eyes, vertical pupils, smooth skin, robust body, slender tail, and sticky toe pads that allow them to climb smooth surfaces. Their coloring varies from gray to greenish-tan or brown or pinkish, with a fine reticulated pattern. The belly is pale with dark speckles.
Halmahera geckos are intermediate-level pet reptiles that aren’t very handleable, but they do make a good display species. With good care, they should have a 15-20 year lifespan.
Minimum terrarium size for halmahera geckos
The absolute minimum terrarium size for a single halmahera gecko is 18”L x 18”W x 36”H. Of course, however, larger is always better! Because this species has sticky toe pads, it’s best for the enclosure to be made from glass rather than mesh or wood.
Housing multiple halmahera geckos in the same terrarium is not recommended, as it is likely to unnecessarily stress your gecko by making them compete for space, food, and other resources.
Do halmahera geckos need UVB?
Technically they can survive without it, but it’s still highly recommended to enable them to thrive in captivity. UVB lighting helps provide a clear day/night cycle, provides all of the vitamin D that your pet needs, strengthens the immune system, facilitates better digestion, and offers other benefits as well.
The best UVB bulbs for halmahera geckos housed in an 18” x 18” x 36” terrarium are:
- Zoo Med T8 Reptisun 10.0, 12”
- Arcadia ShadeDweller Arboreal UVB kit
For best results, house the UVB bulbs in a reflective fixture. Position the lamp on the same side of the terrarium as the heat lamp, 6-8” above the basking branch. UVB is blocked by glass and plastic, so placing the terrarium in front of a window doesn’t count as “free UVB” — in fact it can make your terrarium too hot due to the greenhouse effect.
Lights should be on for ~13 hours/day during summer and ~11 hours/day during winter. And don’t forget to replace your UVB bulb every 6-12 months according to the manufacturer’s recommendation!
Best temperature for halmahera geckos
Halmahera geckos should have a basking temperature of 84-86°F, as measured by a digital probe thermometer with the probe placed on the basking surface. In order to allow for proper thermoregulation, the enclosure should also have a cool area that stays between 75-80°F. This can go down to 70-75°F during winter. Nighttime temps should not go lower than 70°F.
Provide daytime heat for your halmahera gecko with a low-wattage incandescent heat bulb in a hood fixture. Heat bulbs (as opposed to ceramic heat emitters or colored bulbs) are the best way to imitate the warmth of sunlight indoors, and considered to be a superior form of reptile heating by experts. If the bulb is a bit too warm, use a plug-in lamp dimmer or rheostat to reduce its heat output.
You will likely need a lightless heat source for nighttime — ceramic heat emitters work well for this when controlled via nonproportional thermostat.
Best humidity levels for halmahera geckos
Halmahera geckos are tropical lizards, so the humidity inside their enclosure should be fairly high: 60-80% during the day and higher at night. Humidity should be measured via digital probe hygrometer, with the probe placed in the middle of the terrarium.
Increase humidity by misting your gecko’s enclosure 1-2x/day with a spray bottle. Mist every evening and then again in the morning if needed. Aside from raising humidity, this also provides your gecko with an important source of drinking water!
If you have difficulty maintaining high humidity levels, running a reptile humidifier connected to a humidistat at night can help.
Best substrate for halmahera geckos
Providing a layer of naturalistic substrate (“bedding”) will help maintain correct humidity levels and also helps make your enclosure more attractive! We recommend the following substrates for halmahera geckos:
- Zoo Med Eco Earth
- Zoo Med ReptiSoil
- Exo Terra Plantation Soil
- Zilla Jungle Mix
Layering clean, chemical-free leaf litter on top of the substrate can also help with humidity.
Substrate should be at least 2” deep and completely replaced every 3-4 months. Remove poop and urates daily, along with contaminated substrate.
How to decorate a halmahera gecko terrarium
An empty terrarium makes for a bored gecko, reducing its quality of life. Keep your pet entertained and engaged with its environment with the strategic use of décor items that encourage it to exercise natural behaviors!
Since halmahera geckos are arboreal, at bare minimum you will need a branch for your gecko to bask on and some live or artificial foliage for it to hide in. However, it’s best to include other items, such as:
- more branches
- live tropical plants
Make sure that any live plants you use are sturdy enough to withstand your gecko’s weight!
What to feed to a halmahera gecko
Halmahera geckos are omnivores, which means that they need to get their nutrition from both insects and plant matter. Here’s a basic feeding schedule for halmahera geckos:
- Hatchlings and Juveniles (0-12 months) — CGD daily, insects 2-3x/week
- Adults (>12 months) — CGD every 2-3 days, insects 1-2x/week
Feeder insects for halmahera geckos: dubias, discoids, crickets, black soldier flies, hornworms, silkworms, mealworms, superworms
Best crested gecko diets: Pangea, Repashy, Leapin’ Leachie, Zoo Med, Lugarti, Black Panther Zoological, Gecko Pro
You will also need calcium and vitamin supplements to help keep your gecko healthy. The crested gecko diet doubles as a multivitamin supplement, but you’ll still need to dust feeder insects with calcium powder to balance the calcium:phosphorus ratio of minerals. We recommend Exo Terra Calcium Powder.
Of course, don’t forget a small water bowl and feeding ledge for your gecko to drink from! Change the water daily and scrub the bowl with a reptile-safe disinfectant weekly, or whenever it becomes soiled.
How to handle your halmahera gecko
Reptiles generally don’t appreciate petting and handling in the same way that dogs and cats do. Halmahera geckos are one of the types of reptiles that are best to leave alone rather than attempt to handle regularly. Although they’re not particularly bitey, they are very fast and have very delicate skin. If you want to interact with your pet, try hand-feeding it with a pair of feeding tweezers.
*This care sheet contains only very basic information. Although it’s a good introduction, please further your research with high-quality sources. The more you know, the better you will be able to care for your pet!
"Gehyra marginata" by jan_ohlson is licensed under CC BY-NC 4.0.