Geckos are a diverse group of lizards. They are widespread in the wild and are also common household pets. Although most geckos are small, some species can reach incredible sizes. This article will break down all things gecko, plus we’ll investigate the world’s largest gecko species, both living and extinct.
What Is a Gecko?
Geckos are a type of lizard that belong to the infraorder Gekkota. Geckos comprise more species than any other group of lizards — 1,500 distinct species. These lizards vary greatly in size, geography, and coloration. Geckos have very keen night vision and interestingly, many species cannot blink. They lack eyelids, but they have transparent scales over their eyes that they lick to remove debris.
Around 60% of species have pads on their toes that allow them to stick to different surfaces. They are frequently seen climbing up walls and even walking upside down. Unlike most lizard species, geckos are nocturnal, so they are most active at night. Some gecko species can even drop their tails, and many can regrow new ones. Disconnecting their tails is a defense mechanism that allows them to distract predators so they can escape.
Leopard geckos are the most common gecko species kept as pets.
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Where Do Geckos Live?
Geckos live on every continent except Antarctica. The diversity of the many gecko species allows them to inhabit many different ecosystems around the world. They thrive in all types of environments, from rainforests to cold mountain regions. Many gecko species are arboreal and inhabit forested areas. Several species of geckos have been introduced to new areas and have become invasive species, including the Mediterranean house gecko in the United States.
Geckos can be found in urban areas and are even popular pets. One of the most popular pet gecko species is the leopard gecko, which is about 8-11 inches long. In the wild, leopard geckos inhabit dry, savanna-type habitats in Pakistan, Iraq, Iran, Afghanistan, Nepal, and India.
Notable Gecko Species
The giant leaf-tail gecko is native to Madagascar.
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The 1,500 different gecko species vary significantly in size. One of the largest species of living geckos is the Tokay gecko. This species is native to Asia and the Pacific Islands. It reaches up to 16 inches in length, including the tail. Tokay geckos have been introduced in Florida and have an established population there.
Another large species is the giant leaf-tail gecko, which is endemic to Madagascar. The giant leaf-tail gecko can grow up to 13 inches long. In stark contrast, the smallest species of gecko is the Jaragua dwarf gecko. Jaragua dwarf geckos grow to be 0.55-0.70 inches, not including the tail. That is smaller than the diameter of a U.S. quarter.
The Largest Living Gecko Species
New Caledonian giant geckos are arboreal, which means they live in trees.
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Of species living today, the largest gecko is the New Caledonian giant gecko (Rhacodactylus leachianus). This massive lizard can grow up to 17 inches long. It typically weighs between 8-12 ounces.
The New Caledonian giant gecko is endemic to New Caledonia, a French island territory in the South Pacific east of Australia. This gecko is an example of island gigantism. Island gigantism is a biological phenomenon where island animals tend to be larger than their mainland counterparts. This is because predatory mammals are often missing from island ecosystems, so smaller animals, like geckos, evolve over time to fill that niche.
These large geckos are nocturnal and arboreal. This means they are active only at night and live in trees rather than on the ground. Like their gecko relatives, New Caledonian giant geckos are carnivores and eat a variety of invertebrates and some small vertebrates. They also feed on tree sap, fruit, and nectar. Many different gecko species have distinct vocalizations. The New Caledonian gecko has the nickname “devil in the trees” because of its strange, loud growling noise.
The Largest Gecko Species Ever
Including extinct species, the largest gecko ever is Delcourt’s giant gecko. Delcourt’s giant gecko, Gigarcanum delcourti, could grow up to 23.6 inches long, including the tail. Some theorized that Delcourt’s giant gecko was the large, forest-dwelling species referenced in Māori tradition, kawekaweau. However, lack of fossil evidence led scientists to believe that this species did not originate in New Zealand.
While there are no verified reports of seeing this lizard alive in the wild, a taxidermized Delcourt’s gecko was found in the basement of a natural history museum in Marseille in 1983. This is the only verified specimen of this species. Recent DNA evidence has determined the largest extinct gecko’s origins lay in New Caledonia, just like the world’s largest living gecko.
