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1. The Blue-Tongued Skink Family

Lizards, together with snakes, belong to an order of reptiles known as Squamata. On their own, lizards form the suborder Lacertilia (or Sauria), of which there are more than 4,480 species in some twenty families. They exist in greatest number and variety throughout the tropics, and they progressively lessen in number as you move farther away from the equator into the cooler temperate zones. The farther north you go, the fewer lizard species you’ll see. You’ll find just one, the European common or viviparous lizard (Zootoca vivipara), within the Arctic Circle.

Lizards are incredible reptiles that vary tremendously in both size and form. One of the world’s smallest lizards, the Jaragua Sphaero (Sphaerodactylus ariasae), or dwarf gecko—discovered in 2001 on Beata Island off the southernmost point of the Dominican Republic—measures just 0.6 inches (16 mm) from its snout to the tip of its tail. At the other end of the spectrum, the giant Komodo dragon (Varanus komodoensis) reaches almost 10 feet (3 m) in total length and can weigh up to 330 pounds (150 kg).

Their astonishing and varied forms, vibrant and often cryptic colors and patterns, and fascinating and elaborate behavior place lizards among nature’s most beautiful and extraordinary creatures. It is therefore not surprising that they are the most frequently kept exotic animals, second only to tropical fish.

The dwarf gecko (Sphaerodactylus ariasae) is one of the world’s smallest lizards.

The Komodo dragon (Varanus komodoensis) is one of the world’s largest lizards.

Family Scincidae and Genus Tiliqua

Classification

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Squamata

Suborder: Lacertilia (Sauria)

Infraorder: Scincomorpha

Family: Scincidae

Subfamily: Lygosominae

Genus: Tiliqua (Gray, 1825)

One of the most diverse—and possibly the largest—of all of the lizard families is the Scincidae, the skink family, with an estimated 1,400 species in approximately fifty genera. You’ll find them in the tropics and temperate zones throughout the world, with the greatest number occurring in Africa, Southeast Asia, and Australasia. In fact, in some parts of the world—Australia especially—skinks outnumber all other lizard species.

All skinks are somewhat similar in habits and appearance, the features of any one species being fairly characteristic of the majority—namely, a fairly elongated, cylindrical body narrowing toward a comparatively short, at times even stubby, tail; a broad, pointed head; relatively small and, in most cases, highly polished scales; and short limbs. In certain species, such as the Italian three-toed skink (Chalcides chalcides), the limbs are so exceptionally small that they border on being absurd. Going one step further, species such as Greece’s limbless skink (Ophiomorus punctatissimus) has, as its name suggests, no legs at all.

The most prominent, although by no means biggest, skink genus is the Australasian Tiliqua. These are medium to large ground-foraging lizards—attaining lengths of up to 20 inches (50 cm) or more in some species—and include the familiar blue-tongued skinks. With the exception of the Adelaide, or Pygmy, blue-tongued skink (Tiliqua adelaidensis), which is for the most part a hunter of ground-dwelling crustaceans and invertebrates, all blue-tongued skinks are omnivorous, feeding on a wide range of foods from insects, gastropods, and small mammals to fruits, blossoms, and berries.

About Blue-Tongued Skinks

The Tiliqua genus includes several species and subspecies of blue-tongued skink, whose common name is obviously derived from its characteristic fleshy berry-blue tongue. Blue-tongued skinks are mostly large, smooth-scaled, thickset, robust lizards with comparatively short limbs; moderately sized tapering tails; large, broad, triangular heads; and dulled teeth.

Movements

The blue-tongued skink displays its distinctive tongue whenever it is suddenly threatened or alarmed. At such times, it positions itself sideways, with its tilted body bowed, so that its head and tail are directed toward the threat. The skink inflates its body to make it look as large as possible while holding its mouth agape, tongue lolled forward, and usually hissing. This unexpected and rather startling action, often in conjunction with a strong thrash of the tail, usually succeeds in deterring rivals and predators, but the behavior usually disappears in captivity once the skink becomes tame and accustomed to movement and routine disturbances.

Although its movements are normally slow and deliberate, the blue-tongued skink can move quickly over short distances. When alarmed or threatened, for instance, it will often hold its short limbs against its body and wriggle across the ground in a snakelike manner.

The modern blue tongue features a long cylindrical body, a stubby tail, a pointed head, and short limbs.

Habits and Life Expectancy

As with the rest of the genus, the blue-tongued skink is diurnal, spending the daylight hours foraging for food and engaging in its other routine activities, such as basking, defending its territory, courting, and breeding. Although it will occasionally crawl into the lower, thicker branches of shrubs in its search for food and haul itself onto rocky ledges from time to time to bask, its short limbs are not adapted for climbing.

The fact that the blue tongue has a nonspecialized diet means that it can occupy a surprisingly wide variety of habitats. It can live in areas from grassland to semiarid brush scrub, from open forest to rock-strewn steppe. It is also equally at home on the margins of both subhumid tropical forest and semidesert.

During midday, when the sun is at its hottest, the blue tongue seeks out shade and shelter in deserted animal burrows, in rocky crevices, among the roots of trees, in hollow logs, or beneath stones, dead vegetation, or other natural or man-made debris. The skink often uses these same retreats as sleeping quarters at night, when its somewhat flattened body enables it to hide itself easily in such places.

The normal life expectancy for this species in captivity is between fifteen and twenty years, although there are unconfirmed reports of individuals living beyond thirty-two years. Scientists have yet to determine a blue tongue’s longevity in the wild.

To avert a threat, the blue-tongued skink turns and inflates its body to appear larger while opening its mouth wide to hiss.

Scientific Naming System

Every living thing that has ever been discovered and described is given a scientific name, derived from Latin or Classical Greek and consisting of two or three parts. Using this internationally recognized system helps prevent confusion caused by a species having many different common names. The assignment of scientific names to organisms is called nomenclature and, while these names can stand for many years, nomenclature is very fluid, and names are constantly being revised, modified, or changed.

A species is a wide group of similar individuals that are able to reproduce among themselves. Individuals or groups belonging to the same species are called conspecific. Many species are then divided into subspecies (organisms that have characteristic traits that differ slightly from those of their main species). Similar or related species are placed within a genus.

A scientific name is designated in italics and consists of the genus (in this case, Tiliqua) followed by the species (for example, Tiliqua occipitalis—the Western blue-tongued skink). A scientific name consisting of two words denotes an organism that does not have a subspecies. If a plant or animal’s scientific name is three words, the third word indicates either that this is the main species of which there are subspecies or that this is a subspecies. For example: the Northern blue tongue is Tiliqua scincoides intermedia, a subspecies of the Eastern blue tongue Tiliqua scincoides scincoides. A species with the same name repeated twice is the main species, or the pure breed. A subspecies of the Eastern blue tongue is the Kei Island blue tongue, and its scientific name is Tiliqua scincoides keyensis.

So, in summary:

First word = genus name (Tiliqua )

Second word = species name (gigas)

Third word (if the same) = main species (gigas)

Third word (if different) = subspecies name (keyensis)