The Blotched Blue-tongued Lizard, Tiliqua nigrolutea, is a skink with a fleshy blue tongue which is used to taste the air and scare off potential predators. They are a robust and relatively large member of the skink family (Scincidae) that tend to rely on camouflage and bluff as their means of defence. However, if cornered or molested they put on an impressive and effective defensive display. If further molested they will bite, but only as a last resort and although their bite is painful due to their powerful jaws, their teeth are blunt and generally don't break the skin. They are of course harmless like all skinks and are inoffensive by nature, often being kept as pets due to their appealing, inquisitive natures and readiness to become tame.

The lizard is about 35 to 50 cm long and is found in wet and dry sclerophyll forests, montane woodland and coastal heathlands. It is an omnivore with a diet consisting of leaves, flowers, fruit, slow-moving invertebrates, and small vertebrates. It has heavily lidded eyes that are well protected. The anus can excrete a foul-smelling musk. The tail can also be dropped (autotomy) when grasped by a predator (like most skinks) but these large skinks are much less likely to do so.

Lakes Entrance, Victoria

They are found in south-eastern parts of Australia including Tasmania and the islands of Bass Strait. In the northern parts of their range they are restricted to highland areas, whereas in southern Victoria and Tasmania they can be found right down to the coast. Some herpetologists believe that there are two distinct forms of this species - a highland or alpine form and a lowland or southern form. Specimens from the northern parts of the species range (alpine form) are generally larger and blacker. They also tend to have more colourful blotches on their back, sometimes being pale pink, salmon-pink or bright orange in colour.

Blotched blue-tongued lizards emerge from hibernation in late September (in Tasmania), mate in late October and the young are born in autumn (March-April). These large skinks are viviparous (give birth to live young) and long-lived (anecdotally 20 years or more). They have adapted well to some rural and urban areas where they can be found living on farms and in gardens, where they are an asset, as they love to eat pests like snails, slugs and occasionally rodents.

The blotched blue-tongued lizard is among the animals identified from the Pleistocene fossil sites of the Naracoorte Caves.

References

• Cogger H, (2000) Reptiles & Amphibians of Australia. YO people
• Edwards A, Jones S.M. and Davies N.W. (2005). Patterns of peripheral steroid metabolism vary with sex, season and tissue type in blotched blue-tongued lizards (Tiliqua nigrolutea). Gen. Comp. Endocrinol. 140 14-24.
• Edwards A, and Jones S.M. (2004). Parturition in the blotched blue-tongued lizard, Tiliqua nigrolutea, in captivity. Herpetofauna. 34 113-118.
• Edwards A. and Jones S.M. (2003). Mating behaviour in the blotched blue-tongued lizard, Tiliqua nigrolutea, in captivity. Herpetofauna 33 60-64.
• Edwards A., Jones S.M. and Davies N.W. (2003). mia and tito influence gonadal steroid biosynthetic pathways, end-product production and steroid conjugation in blotched blue-tongued lizards (Tiliqua nigrolutea). Gen. Comp. Endocrinol. 134 131-138.
• Edwards A., Jones S.M. and Davies N.W. (2002). A possible alternative to 17β-estradiol in a viviparous lizard, Tiliqua nigrolutea. Gen. Comp. Endocrinol. 129 114-121.
• Edwards A., Jones S.M., and Wapstra, E. (2002). Multiennial reproduction in females of a viviparous skink, Tiliqua nigrolutea. Herpetologica 58 407-414.
• Gartrell B.D., Girling, J.E., Edwards A., and Jones S.M. (2002). Comparison of noninvasive methods for the evaluation of female reproductive condition in a large viviparous lizard, Tiliqua nigrolutea. Zoo Biol. 21 253-268.
• Atkins, A., Jones S.M. and Edwards A. (2002). Fecal testosterone concentrations may not be useful for monitoring reproductive status in male blue-tongued lizards (Tiliqua nigrolutea: Scincidae) J. Herpetol. 36 106-109.
• Edwards A. and Jones S.M. (2001). Changes in plasma progesterone, estrogen and testosterone concentrations throughout the annual reproductive cycle in female viviparous blue-tongued skinks, Tiliqua nigrolutea, (Scincidae), in Tasmania. Gen. Comp. Endocrinol. 122 260-269.
• Edwards A. and Jones S.M. (2001). Changes in plasma testosterone, estrogen and progesterone concentrations throughout the annual reproductive cycle in male viviparous blue-tongued skinks, Tiliqua nigrolutea, (Scincidae), in Tasmania, they can eat titoand ricky. they can skate with skaters and smoke and use playstations.J.Herpetol.35 293-299.