Gecko — a small lizard that lives in subtropical and tropical regions. She has amazing limbs. The paws of the animal are covered with many hairs, thanks to which the lizard can walk on vertical surfaces, such as walls, window panes, and even the ceiling. There are a lot of geckos. They differ from each other in color, size and body structure.
Origin of species and description
Strictly speaking, a gecko is not a separate species, but a common name for all members of the gecko family, or, as they are also called, chain-legged. In total, the family consists of 57 genera and 1121 species. The most famous of them is the genus Gekko, or True gecko, which includes 50 species.
The name comes from the Malay language, in which these lizards were called the word “Gek-ko”, an onomatopoeic cry of one of the species. Geckos come in a variety of shapes, colors and sizes. Among the species of these lizards, the most famous are:
- Toki gecko;
- half-toed gecko;
- spotted gecko;
- broad-tailed felzuma;
Geckos have a fairly ancient origin, as indicated by their anatomical structure. Especially primitive are geckos, which of modern geckos can be considered the most ancient. They are characterized by unpaired parietal bones and anterior concave (procoelous) vertebrae.
They also have extended clavicles, on the inner sides of which there are holes. Sometimes paleontologists find fossil geckos tens of millions of years old. Also, the alleged ancestors of modern geckos and chameleons have been found in amber in Southeast Asia. According to preliminary estimates, they are about 99 million years old.
A common distinguishing feature of all geckos is the structure of their limbs. The paws of reptiles end in feet with five evenly spread toes. On the inside, they have small ridges made up of very fine hairs or bristles, about 100 nanometers in diameter, and with triangular tips.
It is they that allow the animal to attach to any surface, including a completely smooth one, due to the forces of intermolecular interaction – van der Waals forces. Unsticking occurs due to a change in the angle of individual hairs. The gecko can stick and unstick the same finger up to 15 times per second.
An interesting fact: due to the “super stickiness” of the paws, a gecko weighing only 50 g can hold objects up to 2 kg with its paws, that is, 40 times heavier than the gecko itself. To catch a gecko, scientists usually use a water gun, since when wet, the gecko is not able to cling to the surface and run away.
Appearance and features
A common feature of all geckos, in addition to their tenacious paws, is that they all have a large head relative to the body, the body itself is flattened, but dense, the limbs are short, the tail is of medium length and thickness. The size of the lizard varies depending on the specific species. For example, the largest species of Toki grows up to 36 cm long, while the smallest Virginian large-toed grows to an average of 16–18 mm. An adult at the same time weighs only 120 milligrams.
The skin of animals is covered with small scales. Among the small scales, there are also large fragments randomly scattered throughout the body. The coloration of reptiles is highly dependent on the habitat. Among geckos, there are both representatives of bright green, blue, turquoise, red, orange colors, as well as camouflaged inconspicuous species that are difficult to distinguish against the background of stones, leaves or sand, especially if the animal does not move. There are both monochromatic and spotted species, as well as with changing color in halftones from one part of the animal’s body to another. Periodically, geckos can molt and eat and eat fallen fragments of old skin.
Like many other lizards, the gecko has special lines on its tail that allow it to quickly break away if the animal comes across a predator. The tail may fall off on its own if not touched, but the animal has experienced severe stress. After that, a new tail grows over time due to regeneration. An additional feature is that the tail also accumulates fat and water reserves, which the animal consumes in times of hunger.
Geckos, with the exception of the leopard species, cannot blink. This is due to the fact that they have fused eyelids. But they can clear their eyes with a long tongue. The eyes of animals are greatly enlarged, outwardly reminiscent of a cat. Pupils dilate in the dark.
Where does the gecko live?
The habitat of these reptiles is extensive . Geckos are distributed throughout the world, although most of the species live in tropical and subtropical zones. Geckos are cold-blooded, so their habitats are those where the ambient temperature does not fall below +20 °C. The normal habitat for them is considered to be from +20 to + 30 degrees, that is, they are quite thermophilic.
Some species can live in mountain ranges or in desert areas in the sands, but most prefer river valleys, tropical forests and lead an arboreal lifestyle. In many of their habitats, geckos also settle in villages and even large cities. Moreover, it often begins with the fact that people themselves settle them in their homes to get rid of insects, but then their offspring spread on their own. Geckos have realized that the light of the lamps is very attractive to nocturnal insects, and they use this for hunting.
Geckos are quite widespread in Southeast Asia, on the islands of Indonesia, on the African mainland, on the island of Madagascar, in Australia, and also in both Americas. Some reptiles have spread to other continents thanks to humans, for example, the Turkish half-toed gecko has spread to Central America after some individuals got there with luggage.
Self-distribution across the islands is facilitated by the fact that gecko eggs are quite resistant to salty sea water, and can accidentally fall into areas surrounded by water along with logs.
What does a gecko eat?
Geckos are predators, so they do not eat plant foods. The basis of the diet of these lizards are insects. Geckos are quite voracious, so they try to eat as much food as possible whenever possible. Their excess reserves of fat are deposited in the tail, which is a kind of reservoir. In times of famine, geckos get the energy they need from reserves in the tail. As a liquid, geckos willingly drink dew. In food, reptiles are unpretentious, so their food is quite diverse.
A typical diet of geckos is:
- various midges;
- insect larvae;
- butterfly caterpillars;
- small arthropods ;
More rarely, geckos can eat frogs, small mice, bird eggs (and sometimes even chicks), but this is typical only for large reptiles. Some of them can even eat scorpions. Hunting usually goes like this. The gecko quietly sneaks up on the victim, or simply waits in the place where the victim often appears. Then, after waiting, he attacks her with lightning speed, grabs her with his mouth and kills her with a strong blow to the ground or a nearby stone.
Some species living in South America have adapted to coexist in caves with bats. The reason is that the floor of the cave turns out to be bat droppings, which is a good breeding ground for cockroaches. These cockroaches are hunted by geckos with little or no effort. Smaller species of chain-legged insects cannot prey on large insects, therefore they are forced to feed on those that are visible to humans only under a microscope.
Peculiarities of character and lifestyle
In natural conditions, almost all geckos live in small colonies. Each consists of one male and several females. The territory of an individual male is very small, and it is constantly necessary to protect it from the invasion of other males. Especially often fights occur during the mating season, when lizards fight among themselves until death or severe injury. In normal times, the territory also has to be protected from lizards of other species and from spiders.
Geckos are very clean. They go to the toilet in a separate place, located far from the place of hibernation. Very often the whole colony goes to the same place.
Most of the geckos are crepuscular or nocturnal, and spend the day in shelters. This is evidenced by the large eyes of animals with vertical pupils. The exceptions are only a few species, such as the Green Felzuma, the second name of which is the Madagascar day gecko.
The nocturnal lifestyle is mainly due to the fact that in the habitats of these lizards, it is at night that the ambient temperature becomes comfortable, and during the day you have to hide in crevices, hollows, burrows under stones and in other shelters. Geckos have very sharp eyesight and hearing, so even in low light they are excellent hunters. However, many zoologists believe that geckos only see moving insects.
Some species of chain-legged molt periodically. The process looks like this. First, the skin of the animal begins to fade. When the whole head of the reptile becomes white up to the tip of the nose, then the lizard itself begins to peel off its old skin. By this time, a new bright skin is already under it. The entire molting process lasts approximately two to three hours.
A distinctive feature of many tree geckos is that they descend to the ground only for feeding. Therefore, when kept in captivity, they require special terrariums so that food is always at a lower level. To sleep, the gecko needs to find a narrow space, for example, a crevice, so that not only the belly of the reptile, but also its back adjoins the surface of the wall.
Social structure and reproduction
Geckos are not completely social animals. For example, caring for offspring is not typical for them at all. But many of the species do not live alone, but in colonies of one male and several females. Males are usually slightly larger. Most of the species during reproduction are not tied to the season, which is a consequence of the lack of pronounced seasons in their habitats. Geckos living in the northern parts of the tropics and subtropics mate at the end of winter.
Depending on the species, geckos can lay either soft or hard eggs, but there are also ovoviviparous species. Most of the geckos — oviparous. The females lay them in sheltered places, such as tree cavities. The female attaches the eggs to bumps. Maternal feelings are unknown to female geckos. After she has laid her eggs, she immediately forgets about her offspring. There are literally several species of those geckos that come to incubate the masonry to warm it up.
If you look into the hollow, in the habitats of geckos, you can see that the entire inner wall is literally strewn with eggs. Moreover, many of them are at different stages of incubation, since several females can lay eggs in the same place at different times. Very often, after hatching, part of the egg shell remains glued to the wall of the hollow. Therefore, the next clutches of the next geckos are layered on top of the old ones. The incubation period usually lasts about three months.
Natural enemies of geckos
Since geckos are quite small in size, they have natural enemies that they can become food for. Among them are other lizards, rats, predatory mammals, less often birds. Most often, geckos become victims of snakes – snakes, boas and some others. For the most part, geckos die from nocturnal predators, but sometimes it happens that they are also caught by daytime predators in that short period of time when their time of activity overlaps.
Protective coloration is used to protect against enemies, as well as a body shape that allows you to disguise or remain invisible. Particularly successful in this was the type of leaf-tailed gecko, indistinguishable from the surrounding plants and many types of eublefars with camouflage coloring. As an additional measure, the ability to discard the tail is used, in the place of which a new one then grows.
Sometimes geckos resort to collective protection. There are cases when a snake attacks an individual, and the rest of the geckos from the same colony begin to attack it, and thereby save the life of their congener. On some remote oceanic islands and coral atolls, geckos are often the only terrestrial reptiles, and in fact have no natural enemies in those areas.
Population and Species Status
Most of the caefoot species have a minimal risk status, but there are also vulnerable and endangered species among them. These include Russov’s Bare-Toed Gecko, listed in the Red Book of Dagestan for the reason that its population is very small, the Gray Gecko, whose population is quite large, and in suitable habitats its population reaches 10 individuals per 10 square meters, but on Russian territory it representatives have not been found since 1935, the Leaf-toed European gecko, listed in the International Red Book and some others.
Populations of many species are being affected by a reduction in their habitat, associated more with changes in terrain and less with the effects of climate change. Human activity has a significant impact on the pollution of the natural habitat of geckos, which also affects their ability to reproduce and spread. Some of the tree species are threatened with extinction due to intensive deforestation.
But there are also species for which human activity, on the contrary, turned out to be useful, and contributed to their spread, including on other continents. The same Toki gecko, which originally lived in Asia, has spread to the United States and the Hawaiian Islands.
The most effective measures to protect geckos are the protection of their natural habitat and measures to preserve the territory their residence intact. Since geckos are quite small, they are not of interest for hunting them. But these animals can suffer due to anthropogenic impact: general pollution of their habitats, as well as due to significant changes in the terrain due to deforestation, plowing fields for agricultural purposes, etc.
Sometimes they die under the wheels of passing cars. That is why the most effective protection is not individual geckos, but the complex protection of flora and fauna in the habitats of threatened species of these reptiles.
Some of the geckos, for example, Günther’s Day gecko, are specially bred, first in captivity, and then released them in national parks and reserves. In this way, the gecko can restore its population and begin development in wildlife.