Male Leachianus Gecko

Leachianus geckos, or New Caledonian giant geckos (Rhacodactylus leachianus), are the largest geckos in the world. Adults typically reach 9 to 14 inches, with some locality lines pushing toward 16 to 18 inches in total length. They have a heavy body, loose skin, strong jaws and a mottled pattern that helps them blend into bark and moss.

Leachies suit committed keepers with at least some gecko or reptile experience. They tolerate handling when properly socialized, but they are powerful, territorial and defensive if stressed. Bites hurt. They work best for intermediate to advanced keepers prepared to give them a large vertical enclosure and consistent husbandry.

Leachies are semi-arboreal. Height matters. A common minimum for an adult is roughly 24 x 18 x 24 inches, with larger enclosures preferred. Use a front-opening, well-ventilated setup with cork hollows, sturdy branches, vines and dense foliage for hiding and climbing. Substrates that hold humidity without staying soggy work best, such as coco fiber mixes or bioactive setups.

Leachianus geckos prefer cooler, stable conditions compared to many other reptiles. Target an ambient range around the mid-70s Fahrenheit with a gentle warm area up to about 80 to 82 F, and avoid prolonged temps above the mid-80s. Humidity typically sits in the 60 to 80 percent range with a daily drying period so the enclosure does not stay constantly wet. Evening misting of walls and decor works well.

Leachies are omnivorous. In captivity they thrive on high-quality commercial New Caledonian gecko diets (fruit-based meal replacement powders) offered several times per week, plus the occasional appropriately-sized live insects such as crickets or roaches. Insects should be gut-loaded and dusted with calcium and vitamins. Adults typically eat two to three times per week; juveniles need food more frequently.

With proper care, Leachies often live 15 to 20 years, and many sources report 20 to 30 years or more in captivity. They take longer to mature than smaller geckos and produce small clutches, which keeps them relatively high value. Because of their longevity and limited annual egg production, buyers should think in terms of long-term projects and stable, well-planned pairings.