There are six species of blue tongue lizards which come in a variety of sizes and colours, but they all have distinctive blue tongues.
If threatened, it sticks out its large blue tongue and hisses loudly to scare off predators. This display is usually enough to scare many predators into thinking this lizard is dangerous. It is quite harmless.
Blue tongue lizards are the largest members of the skink family known as Tiliqua. It can grow to about 60cm in length. It has a smooth body covered in overlapping scales. Colours vary by species. The Eastern Blue-Tongue, for example, is usually grey with brown stripes across its back and tail. It has a large triangular head with reddish-brown eyes. The Shingleback or Stumpy-Tailed lizard has a short stumpy tail and is dark brown. The scientific name for the blue tongued lizard is Tiliqua scincoides scincoides.
If grabbed by the tail the blue tongue lizard may shed its tail in an attempt to appease its predator and escape. The stump heals quickly and a new, usually shorter, tail regrows in its place. The blue tongue lizard stores excess fat and water in its tail. The loss of its tail during lean times could lead to death by starvation.
Blue-tongues are long-lived. Some live for over twenty years.
Blue tongue lizards are cold-blooded meat and plant-eating skinks that only come out during the day. They are slow-moving animals that are not overtly scared of humans. These lizards get used the presence of humans very quickly and go about their business unperturbed.
Blue tongue lizards are solitary animals that prefer to live alone. Being cold-blooded animals, they start their day by basking in the sun to warm themselves before setting off in search of food. During cold weather, they remain in their shelters beneath logs, rocks, or crevices.
Blue tongue lizards are not dangerous to humans. If provoked, it will bite hard but will let go quickly. The worst damage it can inflict on you are few minor puncture wounds and some bruising.
Blue tongue lizards are found all over Australia. They live in open country with good ground cover such as areas with tall grass, leaf litter, rocks, etc. This environment offers them protection from extremes in temperature and predators. These lizards are territorial living in a fixed area, usually of about a hectare in size and rarely venturing out of its territory.
All Blue tongued lizards are daytime feeders. All except for the pygmy blue-tongue, are foraging omnivores, meaning they eat both plants and animals (meat). They feed on insects, snail, slugs, baby snakes, fruits, berries, and flowers.
They have large teeth and a powerful bite that can crush hard-shelled creatures such as beetles and snails.
The pygmy blue-tongue lizard is the only one which actively hunts its prey which is mostly insects.
It is only during the mating session between September and November that males actively look for females. Males compete and fight aggressively with each other to mate with a female.
Female blue-tongues do not lay eggs. Instead, the embryos develop in the mother's oviduct attached to a placenta. The female gives birth, three to five months after mating, to a litter of about ten live baby lizards. The young are fully functional when born and set out on their own a few days after birth. A blue tongue reaches adulthood in about three years.
There is no evidence to show that blue tongue lizards eat their babies.
While most humans usually leave these harmless animals alone, sometimes humans too cause lizard deaths by accidentally running over them with lawn mowers and cars. Poisoned bait used to kill snails and slugs can also be fatal the blue tongue lizards which may eat a poisoned snail and die.
Most species of blue tongued lizards are common throughout Australia. Some such as the Western Blue Tongue and Central Blue Tongue lizards are classified as vulnerable.