Naultinus facts for kids
Quick facts for kids Naultinus |
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| Northland green gecko (Naultinus grayii) | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Family: | Diplodactylidae |
| Genus: | Naultinus Gray, 1842 |
| Species | |
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See text |
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| Naultinus range species indicated
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Naultinus is a group of geckos found only in New Zealand. These geckos are often called green geckos because of their bright colors. There are nine different kinds, or species, of Naultinus.
These geckos are special compared to most of the world's 2,000 other gecko species. Most geckos are brown, lay eggs, live short lives, and are active at night. But Naultinus geckos are mostly green. They give birth to live young and can live for 30 years or more. They are also active during the day.
New Zealand has a cool, wet climate. Some Naultinus species live in the South Island where it snows in winter. These geckos have special ways to handle cold weather.
Sadly, all Naultinus species are now in danger. Their numbers are shrinking, and they are harder to find. Many populations are very small and close to disappearing. Some have already gone extinct.
The main reasons for their decline are:
- Being eaten by animals brought to New Zealand, like cats and rats.
- Loss of their homes (forests).
- Being illegally caught for the pet trade.
New laws have made punishments tougher for poachers. Scientists are also trying to move geckos to safe islands. But saving these unique animals is still a big challenge.
Contents
Meet the Green Geckos
Naultinus geckos are famous in New Zealand for their bright green color. They are also active during the day. This helps them warm up in the sun. Only the day geckos of Madagascar (called Phelsuma) share these two features. Most other geckos around the world are active at night and are brown or grey.
All Naultinus geckos live in trees. Most are green, but their skin patterns vary. Some are plain, others have spots, and a few have stripes. Sometimes, a rare yellow gecko is found. This is like albinism, a special genetic color.
Most Naultinus geckos are green. But males of two species in the South Island can be different colors. Male N. rudis are grey with white and brown spots. In Canterbury, male N. gemmeus can be grey, brown, or white, while females are green.
When threatened, some species open their mouths wide. This shows off their bright mouth colors, which can be blue, orange, pink, or red. Their thick, fleshy tongues are also colorful. They use their tongues to clean their eyes. Their ears are small holes behind their eyes.
Naultinus geckos have small, bumpy scales. This makes their skin look soft and velvety. However, two species from the South Island are different. The rough gecko (N. rudis) has large, cone-shaped scales all over its body, except underneath. The Marlborough green gecko (N. manukanus) has enlarged scales only on its back and hip area.
All Naultinus geckos have very long, thin tails. These tails can grip things like a "fifth limb." They use them to hold onto twigs and leaves while climbing. They can even hang by their tails! Their toes are also thin, helping them grasp branches.
Green Gecko vs. Forest Gecko
New Zealand has two main groups of geckos: Naultinus and Hoplodactylus. Here are some key differences:
| Hoplodactylus | Naultinus |
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| Mostly grey-brown | Mostly green |
| Active at night | Active during the day |
| Live on the ground or tree trunks | Live in tree leaves and branches |
| Actively hunt for food | Wait for prey to come by |
| Generally move fast | Generally move slowly |
| Can change skin color | Cannot change skin color |
| Wide, non-gripping tails, easily shed | Thin, gripping tails, rarely shed |
| Wider toe pads for climbing smooth surfaces | Thin toe pads for gripping twigs |
Genetics and Species
Scientists find it tricky to define different Naultinus species. Genetic tests show that all nine species are very closely related. They can even breed with each other in the wild. Some scientists think they might just be different "types" of one widespread species.
However, there are clear differences between them. They have different colors, breeding times, and scale patterns. Neighboring species also have slightly different mating seasons. These differences help them stay separate species, even if they can interbreed.
The jewelled gecko (N. gemmeus) is the most unique genetically. Scientists believe it is the ancestor of all other Naultinus species. There are three distinct groups of N. gemmeus in Southland, Otago, and Canterbury. They differ in color and when they breed. Some biologists think these groups should be considered subspecies to help protect them better.
Where Green Geckos Live
The nine Naultinus species live across New Zealand's North and South islands. They also live on some smaller islands offshore. In the past, Naultinus geckos lived all over New Zealand, from the coast up to high mountains.
But now, their numbers have dropped a lot. Their populations are small and spread out. Four species live only in the North Island: elegans, grayii, flavirictus, and punctatus. A new species, N. flavirictus, was identified in 2021. It lives in the far north.
The other five species live only in the South Island: gemmeus, manukanus, rudis, stellatus, and tuberculatus. Each Naultinus species is well-suited to its own local environment. They do not usually live in the same exact places.
Green Gecko Behavior and Life
Daily Life and Diet
Most geckos worldwide are active at night. But all Naultinus species are active during the day. Unlike their relatives, Hoplodactylus geckos, Naultinus cannot change their skin color.
These geckos eat both plants and insects. Their diet includes flying insects like moths and flys. They also eat spiders and other small creatures. New Zealand geckos also eat nectar and berries. For example, they eat the small purple fruits of the Māhoe tree. By doing this, they may help pollinate plants and spread seeds in New Zealand's forests.
Predators and Health
Naultinus geckos have few natural enemies. Some native birds, like the sacred kingfisher, eat them. The tuatara, a large reptile, also eats them on some islands.
All New Zealand geckos can have small orange-red mites on their skin. These mites gather around their eyes, ears, and leg bases. They suck small amounts of blood, but they are usually harmless.
Staying Warm
Naultinus geckos are cold-blooded. This means their body temperature changes with their surroundings. They move to warmer or cooler spots to control their body heat.
Since they live on plants, they get most of their warmth from the sun. If it gets too hot, they move into shaded areas under the leaves. When it's cold, especially in winter, they move from the trees to the ground. They hide under rocks or plants to stay warm.
Because their body temperature affects their energy, they eat more in spring and summer. They eat much less in the colder months.
Defense in North Island Geckos
The four North Island Naultinus species have special ways to defend themselves. When threatened, they open their mouths wide. This shows off their bright mouth colors. N. flavirictus has a bright red mouth, while N. grayii, N. elegans, and N. punctatus have deep blue mouths.
Sometimes, they will lunge at a predator and make a "barking sound." These actions are meant to scare off animals like cats. N. grayii and N. punctatus are known for this aggressive behavior. Some say they do this mostly when protecting their young. When alone, they are usually calm.
Like all New Zealand lizards, Naultinus geckos can drop their tails to escape. But they use their tails for climbing, so they are much less likely to drop them than other geckos.
Reproduction and Life Cycle
Most geckos around the world live only a few years. But Naultinus geckos live a very long time, often 30 years or more. All New Zealand geckos give birth to live young. This is different from most geckos worldwide, which lay eggs.
Female geckos move to warmer or cooler spots to keep their babies at the right temperature inside them. Baby geckos are born a velvety green. They often have white, yellow, or tan markings on their backs. Their color changes to the adult pattern around 15-18 months old. This is when they leave their parents' territory to find their own. This color difference might help adult males recognize young geckos and not attack them.
Pregnancy in these geckos is long, usually about 8-9 months. This is similar to humans!
Green Geckos and People
In Māori Culture
The Māori people knew about reptiles in New Zealand long ago. They carved lizards into wood. Some carvings look like geckos. Māori people generally disliked lizards, except for the tuatara, which they sometimes ate. Seeing a Naultinus gecko was often seen as a bad sign.
As Pets
In New Zealand, you can legally keep Naultinus geckos as pets. But you need a special permit from the DOC. Hundreds of these geckos are kept by private collectors.
In the past, people could catch geckos from the wild for pets. But this changed in 1981 when all native geckos became protected by law. Now, pet owners must get their geckos from other licensed breeders. Selling native lizards is illegal. Keepers must also keep detailed records of their geckos and report them to DOC every year.
Some Naultinus geckos are bred for specific colors and patterns. DOC has even used geckos from private collections for reintroducing them to safe islands. These geckos must be healthy and purebred.
It is very difficult to keep Naultinus geckos as pets in other countries. Strict international rules apply to protect these endangered animals.
Threats to Green Geckos
Naultinus geckos are now rare across New Zealand. This is a big change from the 1960s, when they were common in many areas. The main reasons for their decline are:
- Loss of their homes
- Being eaten by introduced animals
- Illegal collection for the pet trade
For example, barking geckos were common around Wellington until the 1960s. Now, their numbers are very low. DOC has tried to move them to safe islands, but even there, they struggle to survive.
One possible reason for this mystery is wasp predation. Wasps have been seen killing both adult and baby Naultinus geckos.
Predation by Invasive Species
Naultinus geckos are hunted by many animals brought to New Zealand. These include cats, rats, mice, and stoats. Even small predators like mice can cause serious harm. After mice were removed from Mana Island in the 1990s, lizard numbers greatly increased.
Mice can squeeze into small hiding places to catch lizards. They also hunt all year, even when it's cold. Below 5 degrees Celsius, lizards become very slow and cannot defend themselves. This makes them easy targets for mice when they hide on the ground.
Introduced birds also eat Naultinus geckos. Mynas and magpies have been seen hunting them in trees.
Habitat Destruction
When towns grow into forests, it destroys the geckos' homes. This also brings more cats and rats into the area, which hunt the geckos. For example, a unique group of Naultinus gemmeus geckos was lost when their forest home was cleared for building.
Poaching
Naultinus geckos are highly wanted by lizard collectors worldwide.
- They have beautiful colors.
- They are active during the day, so owners can see them.
- They can handle cold weather, so they don't need special heating.
This creates a high demand for them on the black market. Dozens of these protected geckos are illegally taken from the wild each year. Even a small amount of poaching can be devastating for small, isolated populations.
All native New Zealand lizards, including Naultinus, are protected by law. This includes the New Zealand Wildlife Act (1953) and an international agreement called CITES. In 2004, fines and jail times for illegal gecko trade were increased to try and stop poaching.
In 2010, two men were caught trying to smuggle 16 Naultinus gemmeus out of New Zealand. They were jailed for 15 weeks. Naultinus geckos have also been stolen from wildlife parks.
Conservation Efforts
Scientists need more information about Naultinus geckos. It's hard to know how many there are or where they live. This is because they are hard to spot and often hide. Some species have never even been studied scientifically.
Naultinus geckos often hide on the ground during cold or bad weather. They seem to "disappear" and then "reappear" when the weather improves. This hiding behavior has sometimes led people to think populations were just hiding, when in fact, they had gone extinct.
Scientists are trying new ways to find and monitor geckos. They are using special covers on trees for geckos to hide in. They are also trying pheromone lures and even training dogs to sniff out geckos.
Naultinus geckos have been moved to safe, predator-free areas. Their habitats are also being protected, and pest control is ongoing. However, Naultinus geckos breed very slowly. This means their populations recover very slowly.
Species of Green Geckos
Here are the nine recognized species of Naultinus:
- Naultinus elegans Gray, 1842 – Auckland green gecko
- Naultinus flavirictus Hitchough, Nielsen, Lysaght, & Bauer, 2021 – Aupori green gecko, North Cape green gecko, yellow-lipped green gecko
- Naultinus gemmeus (McCann, 1955) – jewelled gecko
- Naultinus grayii Bell, 1843 – Northland green gecko, Gray's tree gecko
- Naultinus manukanus (McCann, 1955) – Marlborough green gecko, northern tree gecko
- Naultinus punctatus Gray, 1843 – Wellington green gecko
- Naultinus rudis (Fischer, 1881) – rough gecko, natural tree gecko
- Naultinus stellatus Hutton, 1872 – Nelson green gecko, starry tree gecko
- Naultinus tuberculatus (McCann, 1955) – West Coast green gecko, Lewis Pass green gecko
See also
In Spanish: Naultinus para niños
