Here Comes the Sun

Exotic pet owners, from reptile keepers to parrot enthusiasts know the importance of UVB for good animal health. However, understanding the requirements of each individual species presents itself as an even greater challenge. Therefore, the industry is currently building on the ‘Ferguson Zones’ model which relates a reptile’s basking behaviour to the correct level of UVB output from artificial lighting. This model allows crepuscular animals such as the crested, gargoyle and New Caledonia giant geckos to receive less than 1 UVI (Ferguson Zone 1), simulating the levels they would be typically exposed to in the wild. 

Peter Blake, Marketing Executive at Reptile Systems has been in herpetoculture for 40 years and believes the Ferguson Zones concept will encourage keepers to provide beneficial UVB for crepuscular species that are sometimes neglected from the wider conversation. He explained: “any animal that lives outside will benefit from the mimicry of natural sunlight. That animal’s relationship to this may just be anything from synchronising its circadian rhythm to full dependency on the heat, light and ultraviolet the sun provides. Even animals that live at the deepest depths are indirectly affected by sunlight in some way. UV also has an impact on the way we keep and raise insects and improvements can be found in the calcium values just by keeping them under good quality light for a few weeks before feeding them to an animal. With some good quality gut-loading and some UV lighting, the insects can be much more nutritious.”

Land of the Giants

The New Caledonia giant gecko is the largest gecko in the world. With males reaching 36cm in length and weighing between 227 and 350 grams, these giants can be distinguished from their slightly thinner female counterparts. Although not as popular as the crested geckos, ‘leachies’ have been in the hobby for a number of years now. Nick explains: “the leachianus are very impressive animals. They suffer from the same disadvantage of cresties in that they’re nocturnal but they’re lovely animals. The island form that many of them are, used to be Rhacodactylus leachianus henkeli but the island forms and the mainland forms are all the same species now. Mine, the island forms are very tame! In fact, I’ve never been bitten by the leachianus whereas it was a daily occurrence with the number of crested geckos I was handling. Again, they’re nowhere near as prolific as the crested geckos. They require pairing up and they either take to each other or they don’t, but the old individuals are the best breeders.”

Leachies can make very appealing pets for those with enough space to house them appropriately. Their easy care and stunning appearance make them suitable for reptile owners looking for a larger pet. While we advise against handling any reptile too often, cresties are much more tolerant than leachies. Those looking for an impressive, easy to care for animal can find great joy in owning a New Caledonia giant gecko, but crested geckos will inevitably be the better choice for first-time keepers or young owners.  

Going Gothic

The gargoyle gecko gets its name from the tiny cranial bumps which resemble horns on the animal’s head. Although, their huge stone-coloured eyes and mossy appearance certainly reinforce its gothic persona. An aesthetically diverse species, gargoyle geckos can vary drastically in colouration and patterning from drab reticulated browns to vibrant red stripes. Of course, captive bred specimens are likely to be more colourful than their wild relatives as demand for the visually striking animals continues to increase. 

Gargoyle geckos should be kept almost identically to crested geckos. A naturally planted arboreal enclosure with a temperature gradient reaching up to 24°C is perfect. Low levels of UVB are encouraged and experimenting with diet mixes and live foods will help the keeper formulate the best diet for their lizard. Just like cresties, gargoyle geckos will drink from a water dish but spraying the enclosure will be their main source of hydration so this needs to be done daily. The most common issue with cresties, leachies and gargoyle geckos is diseases often caused by unclean environments. Ensuring a healthy bioactive or a squeeky clean naturalistic set up will make caring for these geckos relatively simple. 

Fruit Caledonia 

Crested geckos are naturally omnivorous, feeding on a range of fruits, insects and even other reptiles. A study conducted on wild crested geckos in 2007 by French researchers led by Herve Saint-Dizier in New Caledonia found that the stomach contents of wild animals contained the following matter:

Plants: Pollen aggregates 10.3% Soft seeds 1.8% Berries 11.7% Fruit juices 7.52%

Insects: 49.6% (Coleoptera 9.45% Caterpillars and butterflies 7.52% Diptera 3.12% Roaches 6.2% Orthoptera (crickets and locusts) 21.6%

Vertebrates: Smaller lizards (including their own young) 11.4% Other vertebrate prey 8.68% (of which young rodents: 6.42%)

Providing an omnivorous diet in captivity can be extremely rewarding as a keeper. Many tortoise and bearded dragon owners will take great pride in the meals they prepare for their animals and crestie owners are no different. Luckily, simulating the pollen aggregates and fruit juices of the unique New Caledonian flora has become much easier with the popularity of premixed diets and jelly pots. 

Nick Lumb believes that the feeding habits of the New Caledonian geckos are one of their biggest appeals. He explains: “In my experience, the gargoyles and the leachianus are less keen on live food, particularly crickets and things. Crested geckos, especially young ones appreciate the chase. That’s not to say they won’t take them but they’re certainly less bothered. With the gargoyles and the leachies, I feed Repashy and just rotate it every week.”

“Rotating is always a good idea because you can imagine your gecko would appreciate it. I don’t know whether that’s true or not, but I swap them around for that reason. Most of the diets are complete diets, apart from one which is a treat, but they’re all much of a muchness. For feeding leachianus and gargoyles I urge people to go for ‘grubs and fruit’ because it has a higher concentration of insect meal which is black soldier fly larva, so I feed more of that to my gargoyles and leachianus than my cresties who will take insects once a week. Also, certain geckos will prefer different diets and for someone with just a few geckos they will soon learn which is their favourite food.”

Recreating the Wild

New Caledonias flora has the highest levels of endemism in the world, with three quarters of the flora on these islands found nowhere else on the planet. As such, replicating a perfect slice of New Caledonia is difficult, but tropical ferns provide a great starting point. Crested birds nest ferns (Asplenium antiquum) have broad leaves and provide great climbing opportunities when planted high in the terrarium. Rabbits foot ferns (Davallia .sp) also create a brilliant Jurassic look and can be planted into the sides of a bioactive enclosure to provide hiding space.

Recreating the tropical forest environments of New Caledonia is extremely straightforward with new products in the hobby. Of course, a bioactive set up can be extremely rewarding and require a different approach, but species-specific products have surfaced in the market in recent years. Jamie Girling is Product Development Specialist at ProRep and created Crestie Life, a substrate designed specifically for crested geckos. He told Exotics Keeper Magazine “Humidity is really important for crested geckos so designing a substrate that releases humidity gradually was crucial. Egg laying is also important for animals that would typically dig to lay their eggs. If an animal can’t find a suitable place to lay their eggs they can become egg-bound, which is potentially problematic for the animal. But really, Crestie Life came about to move people away from that standard of beech chip or bark chip which would never occur naturally in their environment. Also, people won’t always want to do a Bioactive set up. Obviously, it costs a lot more to create a more complex environment, so the Life series basically replicates some key environmental factors at a lower cost. What’s key for crested geckos is high humidity and Crestie Life was designed with different sized particles to slowly release that moisture over time, contributing to a steady humidity.”

In the wild, many of the New Caledonian gecko species would rarely visit the forest floor. However, our captive environments create new challenges and giving the animals as much space and environmental enrichment as possible is key to overcoming these. Creating a drainage layer with a small reservoir of water beneath will provide a steadier humidity level than spraying the enclosure. 

Next Caledonia

Between 2013 and 2019, New Caledonia saw a 17.5% increase in tourism which made 2019 the busiest year on record. What that means for the flora and fauna is unknown. But, with ecotourism taking centre stage in the travel industry in recent years and New Caledonia’s biodiversity already internationally recognised, the wild geckos of this island should hopefully find some security. As for our much-loved pets in the private sector, the future seems very bright. Captive bred animals are abundant, meaning responsibly sourced pets are never an issue. Advancements in product development are making husbandry much easier and although we might see competition for top spot in the pet trade, the crested, gargoyle and New Caledonia giant geckos will be with us for many years to come.