That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Twenty of the world’s 5,000+ lizard species have been shown to live in family groups (i.e. the Prehensile Tailed Skink, Corucia zebrata, and the USA’s Desert Night Lizard, Xantusia vigilis).  Field studies have now revealed that one social lizard – Great Desert Skink or Tjakura, Liopholis kintorei – actually constructs complex, long-term dwellings and lives in extended family groups.  Native to the red sand plains of central Australia, it is the only lizard known to exhibit such highly-evolved social behavior.

Natural History and Conservation

The Great Desert Skink is stoutly-built, much like the familiar Blue-Tongued Skink (please see photo) and sports rust to burnt-orange coloration that closely matches the red sands in which it lives; its Aboriginal name, Mulyamiji, means “red nose”. 

The diet is comprised largely of beetles, spiders and other invertebrates, with termites being an important food source for part of their active season.  Small snakes, lizards and some vegetation are also taken.  Please click here to view a photo of this most attractive lizard.

The Great Desert Skink’s range has greatly decreased in recent years, and it is classified as Vulnerable by the Australian Government (please see article below for conservation plan).

Skink “Towns”

The degree of social behavior exhibited by the Great Desert Skink is unprecedented among lizards, and has shocked the herpetological community.  Researchers from Macquarie University and Parks Australia have discovered that families comprised of a breeding pair and several generations of offspring cooperatively build complex tunnel systems which are occupied for at least 7 years.

Their subterranean homes have up to 20 entrances and separate latrine areas, and may cover an area spanning 50 feet or more.  Tunnel construction and maintenance duties are carried out by family members based upon size, with the largest individuals doing most of the “heavy lifting”…all seem to contribute some effort, however.

Mate Fidelity and Family Ties

Mated pairs of Great Desert Skinks remain together for years.  Females seem to copulate only with their mate, but 40% of male skinks father young “outside” of their primary relationship.  The young are born alive and remain within the tunnel system of their birth, with their parents and siblings, for several years.  How and when they disperse and breed is being investigated.

Biologists hope that further studies of Great Desert Skink communities will reveal insights into the evolution of social behavior in reptiles and other creatures.

Further Reading

Natural History and Conservation of the Great Desert Skink (Australian Government Report)

Central Australia’s Red Sand Habitats

Social Behavior in the Prehensile-Tailed Skink

Reptiles are often thought of as “unresponsive” by those who are unfamiliar with their ways. Reptile enthusiasts, of course, know better – anyone who has kept a turtle has no doubt been impressed by the speed at which they learn to make associations (especially where food is involved!). Of the turtles, the tortoises seem particularly quick to learn new behaviors.

Aldabra tortoises kept at the Bronx Zoo, to my surprise, adopted a unique strategy to avoid losing their dinners to exhibit mates. At feeding time, each tortoise would lie down on its food tray and slowly edge backwards, eating on the way and so exposing only a tiny bit of its meal to others at any one time!

At a record weight of 240 pounds, African spurred tortoises, the world’s third largest species, seem ill suited as pets. Yet they remain popular, due partly to their engaging ways (please research their needs carefully when deciding upon a pet tortoise – most people are better off with smaller species). Three kept by a friend in a large apartment in NYC would move from room to room throughout the day, following the sun. If a closed door blocked their way, they commenced pounding upon it with their carapaces (upper shells). The racket (and damage to the door) wrought by three frustrated 50 pound tortoises soon “taught” my friend to leave their basking path unimpeded!

You can get some idea of the rewards and difficulties of life with a giant tortoise at:
http://www.tortoise.org/archives/sulcata1.html