Quick Answer
A green lizard is not necessarily a gecko. Gecko is a term used to refer to lizards in the Gekkonidae family, which contains over 1500 species. While some geckos may have green coloration, simply being green does not make a lizard a gecko. There are many different families and species of green lizards that are not geckos.
What Makes a Lizard a Gecko?
Geckos are lizards belonging to the family Gekkonidae. There are over 1500 species of geckos, found on every continent except Antarctica. Some key features that distinguish geckos from other lizards include:
- Large lidless eyes with vertical pupils
- Lamellae – small sticky pads on the undersides of their feet that allow them to cling to surfaces
- Vocal cords – geckos are one of the only groups of lizards that can make sounds
- Tail autonomy – geckos can drop their tails when threatened, which continues to wiggle to distract predators
In addition to physical features, geckos share some behavioral traits such as being nocturnal and excellent climbers. They also have a few physiological adaptations like specialized toe pads and lack of eyelids. Most geckos do not have moveable eyelids and instead have a transparent membrane that protects their eyes. Their toe pads allow them to adhere to almost any surface and rapidly climb.
While many think of geckos being small, drab colored lizards, there is actually incredible diversity among gecko species. They come in a huge range of sizes from just a couple inches to over a foot long. Some have brilliant colors and striking patterns while others have more camouflaged coloration. However, the features that unify them all as geckos are their physical structure, adaptations, and genetics.
What Makes a Lizard Green?
Green coloration provides excellent camouflage in leafy and moist environments. This helps prevent green lizards from being easily spotted by predators. The green color comes from pigments like biliverdin that are present in the lizard’s skin.
Some lizards can actively change their colors through various physiological processes. Chameleons are particularly famous for this. By dispersing or concentrating pigments in their skin cells, some lizards can adaptively match the color of their surroundings.
Other lizards have more permanent green coloration. Green anoles, for example, have fixed green skin that provides camouflage in the trees and foliage they live in. Unlike chameleons, their green color does not change.
So in summary, lizards come in green through two main mechanisms:
- Physiologically altering skin pigments to change color, like chameleons
- Having permanent genetically fixed green coloration, like green anoles
Common Green Lizards
There are dozens of lizard species across different families that can have green colorations. Here are a few examples of common green lizards that are not geckos:
Green Anoles
Green anoles are small lizards belonging to the Dactyloidae family native to Southeastern United States. They have permanent green skin and are adept climbers, often found on branches and trees. Unlike geckos, they lack toe pads and have moveable eyelids.
Green Iguanas
Green iguanas are large arboreal lizards native to the rainforests of Central and South America. They are primarily herbivores. Young iguanas start out brown or orange, slowly turning green as they mature. Iguanas have excellent grip on branches without sticky toe pads like geckos.
Emerald Swift
The emerald swift is a bright green lizard found in the rainforests of Costa Rica and Panama. They have distinctive lime green coloration on their backs and sides. They are part of the Polychrotidae family of anoles. Like other anoles they have adhesive toe pads but lack the fused lamellae of geckos.
Green Tree Dragons
Green tree dragons are found in the tropical forests of Indonesia and have signature hornlike protrusions above their eyes. Their cryptic green coloration allows them to blend into foliage. Despite the name dragon, they are actually a type of agamid lizard.
| Lizard | Family | Key Differences from Geckos |
|---|---|---|
| Green Anoles | Dactyloidae | Moveable eyelids, lack of sticky toe pads |
| Green Iguanas | Iguanidae | Grip branches without toe pads, moveable eyelids |
| Emerald Swift | Polychrotidae | Unfused toe pads unlike gecko lamellae |
| Green Tree Dragons | Agamidae | Lack sticky toe pads, different head morphology |
Are There Green Geckos?
While green color does not automatically make a lizard a gecko, there are in fact many green gecko species. Here are a few examples:
- Moorish Gecko – Found around the Mediterranean, they have bright green coloration often with white spots.
- Madagascar Giant Day Gecko – Native to Madagascar, these large geckos have striking green patterns and red accents.
- Green-Blooded Gecko – A New Zealand species, these geckos actually have lime green blood due to high biliverdin levels.
- Neon Day Gecko – Tropical geckos with fluorescent green and blue colors over their entire bodies.
So in summary, while the defining characteristics of a gecko are not based on color, many gecko species do in fact exhibit bright green skin, helping them blend into leafy environments.
How to Tell if a Green Lizard is a Gecko
To determine if a green lizard is a gecko, look for the following diagnostic features:
- Sticky toe pads – Look under the feet for the presence of setae (hair-like strands) that allow them to grip surfaces.
- Vertical pupils – Geckos have vertical slits unlike the round pupils in other lizards.
- Transparent eyelids – Geckos lack moveable eyelids and instead have a clear membrane.
- Vocalizations – Many geckos can make chirping or clicking sounds.
- Detachable tail – Gently grab the tail and see if it detaches.
You can also look at their habitat and behavior for clues. Most geckos are nocturnal and excel at climbing on all kinds of surfaces like walls and ceilings. If the green lizard is out at night and has an exceptional ability to cling to objects and walls, it is more likely a gecko.
Finally, if identification guides are available, you can match distinguishing visual features like specific scale patterns and head shape. Looking at multiple diagnostic factors will allow confident identification.
Conclusion
In summary, while some geckos are green, a green lizard is not necessarily a gecko. There are dozens of green lizard species across many different families that are not geckos. Gecko refers specifically to lizards in the Gekkonidae family, which have specialized features like sticky toe pads, lack of eyelids, and other adaptations even if they are not green. To identify a green lizard, look for key gecko diagnostic features or use identification guides rather than just color. So while vibrant green coloration provides effective camouflage, a truly green “gecko” may in fact be a different kind of lizard entirely.
