Blue-tongued skinks
Blotched blue-tongued skink (Tiliqua nigrolutea)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Family:	Scincidae
Subfamily:	Egerniinae
Genus:	Tiliqua Gray, 1825[1]
Species
8 extant, see text.
Synonyms
Trachydosaurus

Blue-tongued skinks^[2] comprise the Australasian genus Tiliqua, which contains some of the largest members of the skink family (Scincidae). They are commonly called blue-tongued lizards or simply blue-tongues or blueys in Australia or panana in Indonesia. As suggested by these common names, a prominent characteristic of the genus is a large blue tongue that can be bared as bluff-warning to potential enemies.^[3] The type of predator/threat that is near will determine the intensity of colour present in the tongue. The tongue can also deform itself and produce a thick mucus in order to catch prey.^[4] They are relatively shy in comparison with other lizards, and also significantly slower due to their shorter legs.

Blue-tongued skinks are closely related to the genera Cyclodomorphus and Hemisphaeriodon. All species are found on mainland Australia with the exception of Tiliqua gigas, which occurs in New Guinea and various islands of Indonesia. The Tanimbar blue-tongued skink, a subspecies of Tiliqua scincoides, is also found on several small Indonesian islands between Australia and New Guinea. Tiliqua nigrolutea, the blotched blue-tongued skink, is the only species present in Tasmania.

Most species are diurnal, ground-foraging omnivores, feeding on a wide variety of insects, gastropods, flowers, fruits, and berries.^[5] The pygmy blue-tongue is again the exception, being primarily an ambush predator of terrestrial arthropods.^[6]

All are ovoviviparous, with litter sizes ranging from 1-4 in the pygmy blue-tongue and shingleback to 5-24 in the eastern and northern blue-tongues.^[7]

Name	Scientific Name	Picture	Subspecies
Adelaide pygmy blue-tongue skink	T. adelaidensis (Peters, 1863)
No common name	†T. frangens[8]
Indonesian blue-tongued skink	T. gigas (Schneider, 1801)		T. g. gigas, Giant blue-tongued skink; T. g. evanescens, Merauke blue-tongued skink; T. g. keyensis, Key Island blue-tongued skink
Centralian blue-tongued skink	T. multifasciata (Sternfeld, 1919)
Blotched blue-tongued skink	T. nigrolutea (Quoy & Gaimard, 1824)
Western blue-tongued skink	T. occipitalis (Peters, 1863)
Shingleback, bobtail	T. rugosa (Gray, 1825)		T. r. aspera, Eastern shingleback; T. r. konowi, Rottnest Island bobtail; T. r. palarra, Shark Bay bobtail; T. r. rugosa, Common shingleback, bobtail
Common blue-tongued skink	T. scincoides (White, 1790)		T. s. chimaerea, Tanimbar blue-tongued skink; T. s. intermedia, Northern blue-tongued skink; T. s. scincoides, Eastern blue-tongued skink
Irian Jaya blue-tongued skink	Tiliqua sp.

Multiple extinct species have been proposed. T. frangens, the largest known species of the genus, lived during the Pliocene and Pleistocene epoch around the Wellington Caves of New South Wales in Australia. Another extinct species T. laticephala may represent the same taxon as T. frangens. Its nearest relative is the extant T. rugosa, which is half the size and lacks the bony plates of T. frangens.^[9][10][11]

Another extinct species T. wilkinsonorum also lived during the Pliocene epoch. The earliest possible species is T. pusilla from the middle Miocene, but researchers question whether this species belong to the genus Tiliqua due to its uncertain phylogenetic position that causes paraphyly.^[9]

Some species of this genus are kept as household pets. They are on average very friendly when raised in captivity, and are often called 'the dogs of reptiles'. Captive specimens can live 20 years or longer.^[12]

• Austin, J.J. & Arnold, E.N. (2006). Using ancient and recent DNA to explore relationships of extinct and endangered Leiolopisma skinks (Reptilia: Scincidae) in the Mascarene islands. Molecular Phylogenetics and Evolution 39(2): 503–511. doi:10.1016/j.ympev.2005.12.011 (HTML abstract)
• Bull, C.M. (1988). Mate fidelity in an Australian lizard Trachydosaurus rugosus (Scincidae). Copeia 1987(3): 749-757.
• Bull, C.M. (1990). Comparison of displaced and retained partners in a monogamous lizard Tiliqua rugosa. Australian Wildlife Research 17: 135-140.
• Valentic, R.A. (1996). A prey record of the Eastern Blue-tongue Tiliqua scincoides for the common brown snake Pseudonaja textilis. Monitor 8(3): 155.

Wikimedia Commons has media related to Tiliqua.

Wikispecies has information related to Tiliqua.

• Bluetongue fact file
• Blue-tongued Lizards in New South Wales