Skink

Skink lizards belong to the family Scincidae.  There are about 1,275 species of lizards all around the world. Most of the lizards are secretive ground dwellers or burrowers and located in many parts of the world, that too especially present in Southeast Asia, Australian desserts, North America’s temperate regions, and their nearby islands. The body of the skink animals looks cylindrical in their cross-sectional view.  And most of the species have cone-shaped heads with long and tapering tails. The prehensile-tailed skink Corucia zebrata was recorded as the skink lizard. They can grow and reach a maximum length of about  76 cm (30 inches). But the maximum skink species will grow less than 20cm long.

As the skink lizards have to adopt ground-dwelling and burrowing, they have immoveable lower eyelids which are covered with transparent window scales.  Through the transparent window scales, the eyes of animals are protected from rough particles and allowing the animals to view the world. Some species of blue tailed skink show peculiar characteristics as reduced or absence of limbs and sunken eardrums. The peculiar characteristics vary from arboreal species and semiaquatic species.  

Usually, skinks take insects and other small invertebrates.  Some large skinks are herbivorous and consume a variety of fruits. Some skink animals lay eggs and remaining directly giving birth to the young one. 

[Image will be uploaded soon]

How Skinks Appears? 

Skinks are looking like lizards and belong to the family Lacertidae.  Skinks are also known as true lizards. Most of the skinks species don’t have pronounced necks but some species have relatively small legs. Other species do not have limbs. Some skinks have a head that looks distinguished from the body. The length of legs of the lizards is relatively proportional to their body size. The substantial bony scales cover the skinks of the skull, further, the size and shape of the skull vary depends on the species. Some genera like Neoseps have reduced limbs and fewer than five toes (digits) on each foot. Their locomotion will resemble the snakes during its locomotion. Most of the species have long, tapering, regenerative tails which will store energies and they can shed if a predator grabs them. Skink animals required three to four months to regrow their tails. The small skinks are range from  7.5 to 14.5 cm. The medium-sized skinks range around  12 cm (4.7 inches).  Large skinks can grow up to  35 cm (14 inches).

Behaviours of Skink

Many species of skink are digging and burrowing under the sands. Many species will spend under the ground to secure themself from the predators and sometimes they will dig out tunnels for easy navigation. They will use their tongues to inhale the air and track their prey. When they encounter their prey, they will chase their prey and corner it to manage them to swallow it whole. They can be voracious hunters.

Diet Plan 

Skinks are mostly carnivorous, that too particularly insectivorous. They will take beetles, flies, grasshoppers, crickets, and caterpillars. Some other species also eat moths, millipedes, snails, isopods, centipedes, slugs, isopods, small lizards, and small rodents. Some species in skinks, which are living as home pets have omnivorous characteristics. They will roughly intake 60% vegetables/leaves/fruit and 40% meat (insects and rodents).

Reproduction in Skinks 

Skinks provided a great contribution towards understanding reptile reproduction. Most skink species lay eggs in their nests and abandon them to produce offspring. Some species undergo the live-bearers method, they are known as viviparous. These live-bearing species will develop a complex placenta for transferring healthy nutrients directly to the developing offspring. The species  M. heathi a South American species developed a complex placenta as found in mammals. 

Breading 

Most of the Skink population are oviparous, which will lay eggs in their clutches. About 45% of the skink species are viviparous. Also, many species will remain ovoviviparous. This means the skinklets will develop lecithotrophically in the eggs, then they get hatched inside the mother’s reproductive tracts, further they give birth to the live births. In some genera like Tiliqua and Corucia are producing young ones from the reproductive tract and derives their nourishment from a placenta attached to the fetus from the female as like mammals. These are the example for viviparous matrotrophy. 

Characteristics of Male During Sexual Dimorphism

The male sex hormone of skink animals testosterone will generally get high during the breeding season. The heads of males will become red colour during their reproductive period and muscles in its head of skinks will slightly increase in size.  Further male skinks will become more aggressive towards other males and they pursue females’ attempt to mate with them. Male species can discriminate the sexes based on other skinks chemical signals. The male skinks will pick up through their tongues, here the high receptive sensor organ,  Jacobson’s organ, or vomeronasal organ, which are located in the roof of the mouth will help to identify the sexually receptive and nonreceptive females using this system. 

The sex hormone level will be low in males during its non-breeding season. And they do not show any aggression towards other males and they do not attempt to mate with females. Further, the head of males looks dull brown in colour. Sexual selection assisted males with all the above traits and showing considerable sexual dimorphism. 

Slender Skinks and Five-lined skinks are taken for the study of tail loss as an antipredator mechanism. Like lizards, skinks can also regenerate their tails, once their tails are seized by a predator. Skinks are generally waving and moving their tails in order to direct the predators away from them. Many species will have bright coloured tails, which enhance the distraction effects. If a predator attacked the tail of skinks, it will contract tail muscles to release the tail. Here, the energy stored in the tails is used as fuel to thrashing movements by the released tail, which helps to distracts the predator, and skinks walk away from the predation attempt. The tails are usually regenerated so, that they can regain all other functions of the skinks. In some cases, skinks themselves will lose their tail to have a high probability of escaping from the predator during violent thrashing. Five-lined skinks and slender skinks often regenerate its tail, while returned back to their normal situation further they will regain their lost energy.

Nesting

Skinks will find the protective environment for their livings such as thick foliage, ground-level building, underneath man-made structures..etc. Two or more skinks can find in the small areas of the nest.  Skinks usually find their nest in territorial areas. The skink can lay small white eggs up to 250 at a single time. 

Habitat 

Skinks have unique habitats. Its vegetation depends on the land and the soil in which they live. Skinks belong to the cosmopolitan family are living all over the world, which excludes boreal and polar regions. Many species live in deserts, grasslands, and mountains. Many species are good burrowers and many species are arboreal or terrestrial or fossorial or aqua species. The Skinks which are especially in deserts are sand swimmers. An example of can skinks swim is a mole skink or sand skink in Florida. Some species will show similar actions and are moving through grass tussocks. Most of the skinks are diurnal, which means they are active in the daytime. They all usually spend in bask on rocks or logs during the daytime. 

Genera of Skink Animals & Its Characteristics

1. Keeled skinks belong to the Tropidophorus genera are a semiaquatic species, they are widely found in Southeast Asia to Northern Australia. 

2. Mabuyas belong to Mabuya genera are the ground dwellers, they are widely spread over the tropical regions. About 105 species come under this genera.  

3. Sand skinks from the Scincus genera are also called sandfish. Many may have questions that, can skinks swim. Yes, they can run across and swim through windblown sand, The fringes of scales on toes of sand skinks assign them to run across the sand.  Also, their countersunk lower jaw, partially covered ear opening by the scales, specialized nasal openings, transparent fringes on the immoveable eyelids are facilitating them to move through the sand. These sand skinks are widely spread over in the deserts of  North Africa and southern Asia.

4. Slender Skinks belongs to Lygosoma and other genera. Slender Skinks can encounter from Old world tropics with some new species. They have reduced legs, thick tails and their eyelids are partially transparent. 

5. Snake-eyed skinks belong to Ablepharus and Cryptoblepharus genera. These species can vary their colour. Their fixed plates on their eyes are fixed and they also contain moveable eyelids. Species that come under Cryptoblepharus are widespread throughout the tropical region excluding South America. They are also rafted on debris to islands or they are introduced to many islands by humans. 

6. Genera under Eumeces Skinks are now placed under Plestiodon. Approximately 41 species are placed under the genus Plestiodon. These species have longitudinal stripes. Some species like Great Plains skink (P. obsoletus)  do not have any stripes. The stripes in some skink animal will fade off once the skink reaches sexual maturity. An example of these species is the five-lined skink (P. fasciatus) and the broad-headed skink (P. laticeps). Plestiodon is one of the dominant genera of skink, which can encounter from the north temperate regions of the world as well as Japan and surrounding areas But these species are absent in Europe.

The broad-headed skinks, the five-lined skink are taken as model organisms for the study of behavioural ecology. As both the species can contribute greatly to understanding the lizard’s life and its operation in the natural world. Some Skinks may act as lizards,  they are using chemical signals in social interactions and for finding their prey.  Skinks usually produce different chemical signals to influence their sex hormones and to influence their morphological characters.  This can note from male skinks. 

Predators For Skinks 

Foxes, snakes, raccoons, coatis, crows, coatis herons, lizards, hawks, cats dogs, and other predators of small land vertebrates also fight with skinks and carry as prey. Some skinks have long gestation periods, so it is easy for predators like mongoose to target the predators. This leads to threaten the species habitat and bring to near extinction. Such species are Anguilla Bank skink. The invasion of rodents in the tropical region is the major threat to skinks that too especially tropical skinks.  People in New Guinea and various people from all over the world are also hunting the skinks for their food.