Wildlife lizards

Lizards (Lizard), commonly known as "four-legged snakes" or "snake aunts", are distributed all over the world. It belongs to the cold-blooded reptiles, which have a wide variety of species, and there are about 3,000 species distributed on the earth, and there are more than 150 species known in China. Mostly distributed in the tropics and subtropics, it has a diverse environment, mainly terrestrial, but also arboreal, semi-aquatic and earthy burrowing. Most of them feed on insects, but a few species also eat plants. Lizards are oviparous, with a few oviparous. Lizards are closely related to snakes, and there are many similarities between the two, covering the body with epidermis-derived scales, the cloaca foramen are all transverse fissures, and the males have a pair of interlocutors, both of which are oviparous (or have some oviparous species), and the square bones can be moved.

lizard

Appearance characteristics

The body of a lizard is generally divided into four parts: head, neck, trunk and tail. The skin of the body is leathery scales, and some species have small bone plates under the scales, such as stone dragons, snake lizards, etc. Lizards have small teeth and the shape and length of their tongues vary with species. The eyes are more developed, some species also have craniocystia, except for most geckos, the eyelids are multi-functional, and the cave-dwelling type of eyes are mostly hidden under the skin. Its ears, the eardrum is more exposed, and the eardrum is developed. The left and right lower jawbones are joined by bone slits, so the mouth cannot be opened too wide. Most lizards have limbs, but some have only forelimbs or hindlimbs, with claws at the ends of their fingers and toes. There is a sternum.

There are many kinds of lizards, and their morphological characteristics vary greatly. Among the common lizard species, the golden snake is 16-22 cm long and has an elongated tail, accounting for 2/3 of the body. The length of the torso of the grass lizard is up to 6 cm, the tail length can reach 2 to 3 times the length of the trunk, the back is mainly brown, and the scales have obvious protrusions. There are many species of iguanas, with toothed scales on the surface of the body and spine-like protrusions on the back. Some species of iguanas have an airbag pouch. Chameleon's skin changes color according to its surroundings, with a tongue that extends beyond its body length and paws and tails that are conducive to climbing. The stone dragon is the most widely known of the lizards, with a long, cylindrical body, a pointed nose, a long tail, fine and smooth scales, and small legs so small that it is almost impossible to see. The Lisaurus lizard is medium-sized, active and adaptable. Geckos are very diverse and have large differences in body size. Most of them are small, flattened, have short limbs, have large and prominent eyes but cannot be closed, and have millions of fine villous cilia at the tip of their toes, and are grouped in groups of thousands, making their toes have a great adsorption force, making them good at climbing.

Habits of life

Most of the species are carnivorous, feeding on insects, earthworms, snails, and even rats. However, there are also cacti or seaweed as the main diet, or omnivorous.

Most lizards feed on insects and some rodents, and occasionally eat poultry, with sharp teeth with 3 tips. Herbivores (e.g., iguanas) have broad crowns, leaf-like, and serrated margins. Mollusks and crustaceans (e.g., Dracaena) have blunt rounded teeth at the back of the palate to crush. The Gila monster and its Mexican relative ( Heloderma ) are poisonous , biting when provoked , but rarely fatal , with longitudinal grooves or folds on the medial sides of each tooth in the lower palate to elicit venom. Most lizard teeth are born on the upper palate, anterior palate, and the edge of the tooth bone, while a few species grow on the palate. There are "oval teeth" on the pre-embryonic palate bone, protruding forward from the snout, used to drill through the egg shell, and degenerate after hatching. The way of teeth is mostly lateral, some species are top-born, and the two eyes of the avoidance can move independently. Many lizards have salt glands to expel mineral salts. Shoulder straps are present.

Lizards live in a variety of habitats, living underground, on the surface or in tall vegetation, deserts and islands. The only remaining marine species are the sea iguanas of the Galapagos Islands, which feed on seaweed. There are several species of lizards that are partially aquatic and eat freshwater creatures. The most important environmental factor for lizards is temperature , and many species have their "optimal temperature" and are exposed to the sun to raise their body temperature above the temperature. Species hibernate in cold areas. Day length also has an effect on lizards. Most lizards are oviparous, laying in dug holes, in crevices in trees, rocks, or under the deciduous layer. Some lizards (especially those living at high altitudes and high latitudes) are oviparous or viviparous. Mostly have no egg protection habits, but eumeces fasciatus stays on the egg edge during incubation. A few species ( such as Lazerta and Cnemidophorus ) have parthenogenesis. The cloaca foramen is located on the ventral surface of the base of the tail and is the boundary between the tail and the trunk. The latter is a parthenogenesis of two hermaphroditic hybrids. Many geckos lay their eggs in the same location. Under captivity conditions, the Sheila basilis lizard can live up to 25 years and the gecko can reach 20 years.

Most lizards are active during the day, with geckos moving between twilight and dawn and making loud noises (while most lizards cannot make sounds). Lizards hunt by waiting or searching. Many lizards can cut their tails, and the severed tail can twist rapidly to distract predators, allowing lizards to escape. Many lizards have domain behavior (including domain performances) or courtship performances. Many species have femoral holes that may be used to secrete chemicals to attract the opposite sex. Lizards have little economic significance for humans. Some iguanas are edible and some are tanned. Geckos inhabit the house and can catch pests, but may transmit Salmonella. Lizards are important research materials in biology and are often fed as animals.

Active feeding

Lizards are temperate animals, and lizards living in temperate and cold zones enter a dormant state in winter, showing changes in seasonal activity. Lizards living in the tropics can be active all year round due to the warm climate. But in particularly hot and dry places, there is also the phenomenon of summer sleep to survive the harsh environment of high temperature and dryness and lack of food. It can be divided into three types: daytime activity, night activity and morning and evening activity. The formation of different types of activities mainly depends on the activity habits of food objects and other factors.

Individual lizards have a limited range of motion. Arboreal lizards tend to move only between a few trees. According to several ground-based lizards studied, such as the multi-line southern lizard, the average range of activities is about 1,000 square meters. Some species also show age differences. Newly hatched Sphenomorplus are mostly active near the waters of the hatchery before moving into more distant forests as adults.

Most lizards eat animal foods, mainly various insects. Gekkonids are nocturnal and feed on insects such as Lepidoptera. Larger lizards such as the gecko (clam, Gekkogecko) can also be small birds, with other lizards feeding on them. Monitor lizards (Varanus) can eat fish, frogs and even prey on small mammals. There are also some lizards such as the iguana (Agama) that mainly eat plant foods. Since most species prey on large numbers of insects, the role of lizards in pest control cannot be underestimated. Many people think that lizards are poisonous animals, which is not true. Of the 6,000 species of lizards worldwide, only two are known to be poisonous to the lizard, belonging to the family Helodermatidae, and are distributed in North and Central America.

Self-truncated regeneration

Many lizards often break their tails when they encounter predators or are seriously disturbed, and the broken tail constantly jumps to attract the attention of predators, but it escapes on its own.

This phenomenon is called self-interception and can be considered a protective adaptation to escape predators. Self-amputation can occur anywhere in the tail. However, the place of the tail is not at the joint between the two tail vertebrae, but occurs in the special cartilage septum in the middle of the same vertebra. This special transverse septum is formed during the ossification of the caudal vertebrae and is broken by the strong contraction of the caudal muscles. Cells of the cartilage septum retain the characteristics of embryonic tissue throughout life and can constantly differentiate. Therefore, after the tail is disconnected, a new tail can be regenerated from there. There is no segmented tail vertebrae in the regenerated tail, but only a continuous bone ridge, and the arrangement and structure of the scales are different from the original tail. Sometimes, the tail is not completely broken, so the cartilage is constantly differentiated and regenerated at the self-injury, resulting in another or even two tails, forming a forked tail. Lizards of the gecko family, snake lizard family, lizard family and stone dragon subfamily in China have the ability to self-intercept and regenerate.

Discoloration sounds

Lizards are highly color-changing, especially Chamaeleons, who have earned the reputation of "chameleons" for their ability to change color. Most of China's tree lizards and dragon lizards also have the ability to change color, among which the color change tree lizard (Calots versicolor) in the dry place where the sun shines throughout the body becomes lighter and the head and neck are red, when turned into a wet place, the red gradually disappears, and the whole body color gradually darkens. Discoloration of lizards is an involuntary change in physiological behavior. It is related to the intensity of light, changes in temperature, the excitement of the animal itself, and the health of individuals.

Most lizards are silent. Geckos are an exception, and many species can make a loud sound. Clams can be heard from meters away. The cry of a gecko is not a sign of a couple, but may be a warning or territorial signal.

Sprinters

Most lizards have four legs, with powerful hind limbs that can run fast and change direction. The fastest running lizards can reach speeds of up to 25 km/h. Some lizards can run as fast as they can with just two long hind limbs, and can run while maintaining direction with their tails. The king lizard has the fastest speed of any time, reaching 20 to 25 km/h, and can remain on the surface even when running on the surface.

Grow and reproduce

The lifespan of lizards is mainly based on zoo breeding data, flying lizard 2 to 3 years, island lizard 4 years, multi-line southern lizard 5 years, monitor lizard (Varanus salvator) 12 years, helodermaspentum (Helodermaspentum) 25 years, the longest record is probably a snake lizard (Anguis fragilis) 54 years. These figures do not fully reflect the actual situation in nature and can only be used as a reference.

Lizards have handovers and are in vivo fertilized. Mating and reproduction are generally carried out in late spring and early summer. Some species of sperm can remain viable in the female for several years, and after mating once, they can produce fertilized eggs for several consecutive years. Only female individuals are found in some lizards, and according to studies, they are species that breed parthenogenesis. The chromosomes of these lizards tend to be alloploid. Some species that normally reproduce by both sexes will switch to parthenogenesis breeding under certain environmental conditions, and it is believed that parthenogenesis breeding is conducive to the participation of all members in the production of offspring, and is conducive to rapidly expanding the population and occupying the living field.

Most species of lizards are Oviparous and generally lay their eggs in warm, humid and hidden places in the summer. The number of eggs varies from one or two to a dozen. The size of the egg has a certain relationship with the size of the individual of this species. The eggs of the gecko family are slightly rounded, the shell is more calcareous, and the shell is hard and brittle. The eggs of various other lizards are mostly oblong in shape, with leathery and flexible shells.

Some lizard eggs begin to develop in the posterior segment of the maternal fallopian tube ("uterus") until they give birth to lizards, called Ovoviviparous. Many species in the family Lithopodidae are oviparous, and most of the other lizards of the family are oviparous. Some species in the same genus are oviparous, while others are oviparous. For example, the mabuya multifasciata in the genus Mabuya multifasciata is oviparous, and the doling southern lizard (M. multicarinata) is oviparous. Another example is the two similar species of the Slippery Lizard in the genus, the Qinling Slippery Lizard (Scincella. tsinlingensis) is an oviparous fetus, while the Kangding slippery lizard (S. Potanini) is egg-born. China's endemic crocodile lizard (shinisaurus crocosilurus) matured in the maternal fallopian tube at the end of that year, but it was delayed until May of the following year. Dissecting crocodile lizards in the late stages of pregnancy, mature lizards are no longer yolk, while the walls of the maternal fallopian tubes are covered with a network of microvascular networks. Lizards that may be late in development rely on the mother for nutrition and should be one of the few Viviparous lizards.

Lizards generally breed once a year. However, some species in the warm and humid tropical environment, such as the island lizard (Emoiatrocostata), the multi-line southern lizard, the scorpion tiger (Platyurus plaryurus), the warty-tailed lizard tiger (Hemidactylus frenatus) and the gehyra mutilata (Gehyra mutilata) can breed all year round.

Habitat

Lizards mostly live at altitudes of about 1,000 meters or less. A few species can live in high mountains at an altitude of about 2,000 meters, such as Qinling slippery lizard, mountain slippery lizard, Kangding slippery lizard and so on. The Tibetan sand lizard and the Hiyama iguana are among the few lizards with the highest vertical distribution, and their living areas are often around 4,000 meters above sea level.