Geckos are some of the most fascinating reptiles on Earth. They can be found on every continent except Antarctica and come in a wide variety of sizes and colors. Geckos belong to the infraorder Gekkota, which includes over 2,000 different species! This blog post will provide you with some basic information about geckos – what they are, where they live, and what they eat. We hope you enjoy learning about these amazing creatures!
Geckos are small lizards that live in warm climates all over the world. They eat mostly meat and can be found on every continent except Antarctica. Geckos come in a wide range of sizes, from 1.6 to 60 centimetres long.
Gekkonidae is the family of lizards that includes most geckos species. They are unique among this group for their vocalizations, which differ from species to species and range in type depending on what sounds they make often when interacting with others or alarm calling out If you’re around them.
Gecko sounds
Geckos make different sounds than other lizards. Most geckos in the family Gekkonidae use chirping or clicking sounds in their social interactions. Tokay geckos are known for their loud mating calls, and some other species are capable of making hissing noises when alarmed or threatened. They are the most species-rich group of lizards, with about 1,500 different species worldwide.
The Indonesian-Malay gekoq, which is inspired by sounds produced by some species, gave rise to the New Latin gekko and English ‘gecko.’
Geckos and their eyelids
All geckos, except for a few kinds, do not have eyelids. They have a transparent membrane on the outside of their eyeballs that helps keep the eyeball clean and moist. Geckos without eyelids generally lick their own corneas when they need to clear them of dust and dirt.
Exceptions are geckos in the families Eublepharidae, Cyclangamidae, and Phytodactylidae; they do not have eyelids. Instead, the outer surface of the eye has a transparent membrane called the cornea. The eyes of lizards are designed to keep their pupils dilated in low light. They have a solid lens within each iris that grows larger in darkness to allow more light in. Species without eyelids lick their own corneas when they need to clean them of dust and grime, since they are unable to blink.
Geckos are nocturnal
Geckos are different from most lizards because they are usually nocturnal. This means they are awake at night and have good night vision. They can see 350 times better than humans in low light. Gecko eyes have evolved from diurnal species, which means these lizards used to be awake during the day. But over time, they lost the rod cells in their eyes. So now, their cone cells have changed and increased in size into two different types- single and double.
There are three photo-pigments that have been retained. They are sensitive to ultraviolet, blue, and green light. They also use a multifocal optical system which allows them to generate a sharp image for at least two different depths. Some gecko species are nocturnal, but other species are diurnal and active during the day. This has evolved multiple times independently.
Gecko toe-pads
Geckos are well-known for their special toe pads. These toe pads help them to grip onto smooth, vertical surfaces and even cross indoor ceilings with ease. Geckos live in warm regions of the world, and many species make their home inside human habitations.
Some animals, like the house gecko, can become part of your indoor menagerie. People usually like these animals because they eat insect pests, including moths and mosquitoes. Geckos are like most lizards in that they can lose their tails if they need to escape from a predator.
The largest gecko
The largest species of gecko is the kawekaweau. It is only known from a single, stuffed specimen that was found in the basement of a museum in Marseille, France. This gecko was 600 millimeters (24 inches) long and it likely lived in New Zealand where it lived in native forests.
The kawekaweau gecko was probably wiped out when new invasive species were introduced to the country during European colonisation. These new species, such as rats and stoats, killed many of the native animals.
The smallest gecko
The smallest gecko is the Jaragua sphaero. Measuring in at only 1.6 inches, this minuscule creature is one of the tiniest reptiles in the world. Despite its size, the Jaragua sphaero is a fierce predator, preying on insects and other small animals.
Interesting gecko traits
The gecko has some interesting traits. For example, they can climb walls and they have a sticky toe pad that helps them stay attached to surfaces.
Geckos are like other reptiles in that they are ectothermic. This means their body temperature is affected by the temperature of their environment. Additionally, in order to do things like move, eat, and reproduce, geckos need a relatively high temperature.
Gecko molting and shedding
All geckos regularly lose their skin. Some species do it every two to four weeks, while others do it once every one to two months. Leopard geckos lose their skin every two to four weeks.
They need moisture to help them shed, so they often live in humid places. When shedding starts, the gecko eats the loose skin from its body. Young geckos lose their skin more often – once a week – but when they are fully grown, they only shed once every one to two months.
Adhesion abilities for geckos
Almost 60% of all gecko species have adhesive toe pads which allow them to stick to most surfaces without needing liquids or surface tension. Such pads have been gained and lost multiple times over the course of gecko evolution. Adhesive toe pads evolved separately in around eleven different gecko lineages, and were lost in at least nine lineages.
Some people used to think that the setae on gecko feet helped them stick to things. This was because of a weak chemical force called van der Waals’. This force doesn’t involve any fluids. In theory, a synthetic boot with these same setae would stick to things as easily as a gecko’s foot does. But this doesn’t always happen because it depends on the humidity. A recent study suggests that the adhesion of geckos is mainly determined by electrostatic interaction (caused by contact electrification), not van der Waals or capillary forces.
Geckos have special hairs on their feet that help them clean themselves and remove any dirt. Polytetrafluoroethylene (PTFE), which is a very smooth surface, is difficult for geckos to stick to.
Gecko adhesion is typically improved by higher humidity, even on hydrophobic surfaces. However, when the surface is completely immersed in water, the gecko adhesive is reduced. The role of water in that system is being discussed. But recent experiments agree that if there are water layers on the setae, it will increase the surface energy and the gecko adhesion force. The elastic properties of the b-keratin also change with water uptake.
Gecko toes are able to bend in two different directions. This is called hyperextension. Gecko toes can bend backwards, which is different from how human fingers and toes work.
Geckos can walk on walls and ceilings because of a special force called the van der Waals force. This force is overcome by peeling their toes off surfaces from the tips inward. Geckos separate spatula by spatula from the surface, so for each spatula separation, only some force necessary.
Most of the time, geckos’ toes work well even when they are not making full contact with a surface. This is because they have a lot of margin for error depending on how rough the surface is and how many setae are in contact with it.
The small van der Waals force requires a lot of surface area. For every square millimeter on a gecko’s footpad, there are about 14,000 hair-like setae. Each seta is about 5 micrometers wide. Human hair is between 18 and 180 micrometers wide, so the cross-sectional area of human hair is equivalent to 12 to 1300 setae. Each seta is tipped with between 100 and 1,000 spatulae. These spatulae are each 0.2 micrometers long (one five-millionth of a meter), or just below the wavelength of visible light.
The setae of a typical mature 70-gram (2.5-ounce) gecko can hold up a weight of 133 kilograms (293 pounds). This is because each spatula can exert an adhesive force of 5 to 25 nN. The exact value of the adhesion force depends on the surface energy of the substrate to which it adheres.
Studies have shown that the amount of surface energy from long-range forces, like van der Waals forces, depends on the material’s structure below the surface. This means that the strength of the adhesive can be figured out by looking at how deep into the material the force affects.
Besides their setae, geckos also have phospholipids. These fatty substances help to lubricate the setae and allow the gecko to detach its foot before taking the next step.
The origin of gecko adhesion likely started when they changed the way their skin looked on the bottom of their toes. This was recently discovered in the Gonatodes genus from South America. They changed simple bumps on their skin into tiny hairs, which helps them climb smooth surfaces and sleep on smooth leaves.
Some technologies are being designed to copy how geckos stick to surfaces. These technologies could create reusable, self-cleaning adhesives for many purposes. However, creating synthetic setae is not an easy task.
Gecko skin facts
The skin of the gecko does not have scales, but it has a papillose surface at a micro scale, which is composed of hair-like projections that cover the whole body.
These confer superhydrophobicity, and the unique design of the hair confers a profound antimicrobial action. These protuberances are very small, up to 4 microns in length, and tapering to a point. Gecko skin has been observed to have an anti-bacterial property, killing bacteria when they come in contact with the skin.
The mossy leaf-tailed gecko of Madagascar, U. sikorae, has coloration that helps it camouflage into its surroundings. Most are greyish brown to black or greenish brown, with markings that look like tree bark. They also have flaps of skin, running the length of their body, head and limbs, known as the dermal flap. This flap can help them blend in with the shadows and make themselves practically invisible.
Gecko teeth
Geckos are polyphyodonts, which means they can replace each of their 100 teeth every 3 to 4 months. Near the full grown tooth is a small replacement tooth that is growing from the odontogenic stem cell in the dental lamina. The formation of teeth is pleurodont; they are fused (ankylosed) by their sides to the inner surface of the jaw bones. This formation is common in all species in the order Squamata.
Classification and taxonomy of geckos
Geckos are members of the infraorder Gekkota, which comprises all geckos as well as the closely related snake-like Pygopodidae and blind lizards.
The infraorder Gekkota is divided into seven families, containing about 125 genera of geckos, including the snake-like (legless) pygopods. These families are the Diplodactylidae, Carphodactylidae, Gekkonidae, Eublepharidae, Phyllodactylidae, Sphaerodactylidae, and Pygopodidae.
Possible extinct geckos which cannot be placed into these seven families include Cretaceogekko and Yanatarogecko. Legless lizards of the family Dibamidae, also referred to as blind lizards, have occasionally been counted as gekkotans, but recent molecular phylogenies suggest otherwise.
There are possible extinct geckos which cannot be placed into these seven families. These include Cretaceogekko and Yanatarogecko. Legless lizards of the family Dibamidae, also referred to as blind lizards, have occasionally been counted as gekkotans, but recent molecular phylogenies suggest otherwise.
Gecko families
Below is a table outlining the seven families of geckos. Click on the gecko family that you which to learn more about.
| Gecko Family | Common Name | Example of Gecko |
|---|---|---|
| Carphodactylidae | Northern Leaf-tailed Geckos | Chameleon Gecko (Carphodactylus laevis) |
| Diplodactylidae | Australian Geckos | Smooth Knob-tailed Gecko (Nephrurus levis) |
| Eublepharidae | Eyelid Geckos | Leopard Gecko (Eublepharis macularius) |
| Gekkonidae | True Geckos | Tokay Gecko (Gekko gecko) |
| Phyllodactylidae | Leaf-toed Geckos | Turkish Gecko (Hemidactylus turcicus) |
| Pygopodidae | Flap-footed Lizards | Delicate Slider (Lerista delicatula) |
| Sphaerodactylidae | Dwarf Geckos | Cuban Ashy Gecko (Sphaerodactylus elegans) |
Common and popular gecko species
More than 1,850 species of geckos are found all around the world. They come in many different colors, sizes, and patterns. Some geckos can even change colors to help them blend in with their surroundings.
Below are some of the more common and popular species of geckos, often kept as pets to both kids and reptile enthusiasts.
Western banded gecko (Coleonyx variegatus)
The western banded gecko, Eloleonyx variegatus, is found in the southwestern United States and northwest Mexico.
Bent-toed gecko (Cyrtopodion brachykolon)
The bent-toed gecko, Cyrtopodion brachykolon, lives in northwestern Pakistan and was first identified in 2007.
Leopard gecko (Eublepharis macularius)
The leopard gecko, Eublepharis macularius, is the most popular gecko kept as a pet. It has nonadhesive toe pads and can’t climb a vivarium’s glass.
Stump-toed gecko (Gehyra mutilata, Pteropus mutilatus)
The stump-toed gecko (Gehyra mutilata), which is also known as the stump-toed pteropus, has the ability to modify its color from very light to extremely dark in order to conceal itself. This lizard is capable of hiding in both natural and residential settings.
Tokay gecko (Gekko gecko)
The Tokay gecko (Gekko gecko), a large, widespread Southeast Asian lizard renowned for its aggressive nature, loud mating howls, and brilliant markings.
Common house gecko (Hemidactylus frenatus)
The common house gecko, Hemidactylus frenatus, thrives around people and human habitation structures in the tropics and subtropics worldwide.
Indo-Pacific gecko (Hemidactylus garnotii)
The Indo-Pacific gecko (Hemidactylus garnotii), which lives in tropical houses throughout the world and is now an invasive species in Florida and Georgia in the United States,
Tropical house gecko (Hemidactylus mabouia)
The tropical house gecko, Hemidactylus mabouia, is a species of house gecko native to sub-Saharan Africa and now found in North, Central, and South America and the Caribbean.
Mediterranean house gecko (Hemidactylus turcicus)
The Mediterranean house gecko, Hemidactylus turcicus, is a common sight in and around buildings and is an exotic species in the United States.
Mourning gecko (Lepidodactylus lugubris)
The mourning gecko, Lepidodactylus lugubris, is a distinct species native to Asia and the Pacific that can adapt to both natural and residential areas.
Bibron’s gecko (Pachydactylus bibroni)
Pachydactylus bibroni, known as Bibron’s gecko, is a southern African lizard that is a household pest.
Gold dust day gecko (Phelsuma laticauda)
The gold dust day gecko, Phelsuma laticauda, is a diurnal animal that may be found in Madagascar and the Comoros. It has also been introduced to Hawaii.
Flying geckos (Ptychozoon genus)
Ptychozoon is a genus of arboreal geckos from Southeast Asia known as flying or parachute geckos; they have wing-like flaps from the neck to the top of their legs to help them hide on trees and obtain lift while jumping.
Crested gecko (Rhacodactylus ciliatus)
The crested gecko, a gecko species known as Rhacodactylus ciliatus (now classified in the genus Correlophus), was thought to be extinct until rediscovered in 1994 and is becoming increasingly popular as a pet.
New Caledonian giant gecko (Rhacodactylus leachianus)
The New Caledonian giant gecko, Rhacodactylus leachianus, was first identified by Cuvier in 1829; it is the heaviest living species of gecko.
Dwarf gecko (Sphaerodactylus ariasae)
Sphaerodactylus ariasae, the dwarf gecko, is found in the Caribbean Islands and is the world’s smallest lizard.
Crocodile gecko (Tarentola mauritanica)
The Tarentola mauritanica, also known as the Moorish gecko or crocodile gecko, is a gecko that can be found in the Mediterranean region from Spain to Greece and northern Africa. Their pointed heads, spiny skin, and tails reminiscent of those of a crocodile are among their most notable features.
Summary
Geckos are a diverse group of lizards found on every continent except Antarctica. They vary in size and color, but all share some common characteristics, such as adhesive toe pads and the ability to change color. Some gecko species are better adapted to living in natural surroundings, while others have adapted to living around humans and thrive in residential areas. Geckos are interesting creatures that make great pets, and with so many different species to choose from, there’s sure to be one that’s perfect for you.