How to Care for Your Halmahera Gecko

The halmahera gecko (Gehyra marginata) is also known as the halmahera giant gecko or the ternate dtella. They’re a large, crepuscular, arboreal lizard native to Halmahera island in Indonesia. They prefer to spend most of their time in the trees of tropical forest areas, but are also known to inhabit human dwellings.

Halmahera geckos are known to grow up to 11-12” long, and have a blunt triangular head, slender prehensile tail, and loose, velvety skin. Their feet feature large, sticky toe pads and their lidless eyes are green with a reticulated pattern and vertical pupils. Coloring may be gray, tan, greenish, pinkish, or brown, with a reticulated pattern. The underside is pale with dark speckling.

Halmahera geckos are fairly hardy, but they don’t make a great pet for beginners because they’re not particularly handleable. With good care, they can live 15-20 years.

How much space do halmahera geckos need?

Halmahera geckos may be overall similar to the more popular crested gecko, but their size means that they need a larger enclosure. A single halmahera gecko should be housed in no smaller than a 18”L x 18”W x 36”H terrarium (or equivalent), preferably front-opening for easy access. However, larger is always better, and will be happily used!

Cohabitation (keeping multiple halmahera geckos in one enclosure) is not recommended, and may result in fighting if attempted.

Do halmahera geckos need UVB?

As a nocturnal species, they can survive without it as long as they get the right supplements, but it’s still recommended. UVB gives them all of the vitamin D that their bodies need, stimulates better appetite and activity, and generally allows them to be healthier than they would be without.

Halmahera geckos do best with low-strength UVB as part of their enclosure. The best UVB bulbs for these geckos when housed in a 36” tall terrarium are:

• Zoo Med T8 Reptisun 10.0, 12”
• Arcadia ShadeDweller Arboreal UVB kit

The UVB bulb should be housed in a reflective fixture (Arcadia or Vivarium Electronics) and placed close to the heat lamp, about 6-8” above the basking branch. UVB is blocked by glass and plastic, so you can’t give your gecko UVB by placing its terrarium in front of an open window. UVB bulbs decay over time, so you will need to replace it every 6-12 months to maintain performance, depending on manufacturer recommendation.

Halmahera geckos should receive 11 hours of light during winter and 13 hours of light during summer. This simulates natural seasonal changes in day length and encourages healthier hormonal rhythms.

What basking temperatures do halmahera geckos need?

Despite popular myth, Halmahera geckos do benefit from having a low-temperature basking area. After all, they’re still ectotherms, which means that they need a temperature gradient in their enclosure to help them regulate their metabolism and stay healthy.

Halmahera geckos should have a moderate basking temperature around 84-86°F, as measured by a digital probe thermometer with the probe placed on the basking surface. The cool zone in the lower regions of the enclosure should stay between 75-80°F in summer and can drop to 70-75°F in winter. Heat lamps should be turned off at night. Nighttime temperatures can drop as low as 70°F.

Provide heat for your gecko by imitating the sun with a low-wattage heat bulb placed on one side of the enclosure in a hood fixture. Do not use ceramic heat emitters (CHEs), red bulbs, or blue bulbs, as these are not as effective.

What humidity levels do halmahera geckos need?

Halmahera geckos need a high humidity environment with an average humidity of 60-80%, although it can drop as low as 50% during the day and spike as high as 100% at night. Monitor humidity levels with a digital probe hygrometer with the probe in the middle of the terrarium. 

Misting your gecko’s enclosure with a sprayer each evening and again in the morning will help create the right humidity levels. It also provides an important source of drinking water! If you live in a particularly dry climate, using a reptile humidifier throughout the night will be beneficial.

What substrate is good for halmahera geckos?

Although halmahera geckos are an arboreal species and don’t spend much time on the ground, placing a layer of substrate on the floor of the enclosure helps maintain humidity. As an added perk, it also tends to make the enclosure more attractive.

Ideally, this substrate should resemble what halmahera geckos naturally live on in the wild — in this case, tropical soil. It should have small particles and hold moisture well. 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.

What décor can you use in a halmahera gecko terrarium?

It’s terribly boring for a gecko to be stuck in an enclosure with nothing in it except substrate and food/water bowls. It doesn’t matter how big the enclosure is if you don’t put things in it for your pet to use and interact with. Halmahera geckos appreciate a fairly densely planted enclosure with either live or artificial plants, which can make their terrarium a great piece of home décor!

At bare minimum, you will need a branch for your gecko to climb on and some live or artificial foliage for it to hide in. However, it’s best to include other items, such as:

• more branches
• vines
• cork tubes
• ledges
• tropical live or artificial plants

What do halmahera geckos eat?

Halmahera geckos are omnivorous, which means that they need to eat a balanced diet of plant and animal matter in order to get the nutrition that their bodies need. In the wild, they primarily eat insects and fruit. In captivity, it’s best to feed them high-quality, specially-formulated crested gecko diet (CGD) supplemented by live insect feeders.

How often halmahera geckos need to eat depends on age:

• Hatchlings and Juveniles (0-12 months) — CGD daily, insects 2-3x/week
• Adults (>12 months) — CGD every 2-3 days, insects 1-2x/week

Because halmahera geckos are arboreal, CGD should be offered via wall-mounted feeding ledge, not placed on the ground.

Best crested gecko diets: Pangea, Repashy, Leapin’ Leachie, Zoo Med, Lugarti, Black Panther Zoological, Gecko Pro

Feeder insects for halmahera geckos: dubias, discoids, crickets, hornworms, silkworms, mealworms, superworms, black soldier flies 

Remember, the key to great nutrition is variety!

Supplements

Although crested gecko diet doubles as a vitamin supplement, you will need calcium powder to dust on feeder insects. We recommend Repashy Supercal NoD.

Water

Although your gecko will get most of its drinking water from daily mistings, it’s a good idea to also provide a wall-mounted water dish. Change the water daily and scrub the bowl with a reptile-safe disinfectant weekly, or whenever it becomes soiled.

Do halmahera geckos like to be handled?

Few reptiles actually “like” to be held, and although other Indonesian geckos generally tolerate handling well, halmahera geckos prefer that you keep your hands off, and they’re generally best as a display animal. Plus, they’re incredibly fast and have very delicate skin, which further rules them out for handling.

*This care sheet contains only very basic information. Although it’s a good introduction, please do further research with high-quality sources to obtain additional information on caring for this species.