Before that phone call, only a handful of official sightings of the small lizard had been recorded. In his 1929 guide The Reptiles and Amphibians of South Australia, Edgar Waite, a leading herpetologist and ichthyologist, referred to the pygmy blue tongue (Tiliqua adelaidensis) as ‘the doubtful blue tongue’, because he doubted whether it was a real species, or just the young stage of a larger bluetongue.
Graham’s specimen had only been found by accident — a surprise package in the belly of a brown snake killed on the road between Burra and Morgan, South Australia. Mark, Graham and their colleagues quickly sprang into action.
Once the scientists knew where to look, they were easily able to trap additional specimens of the lizard and start on an accurate species description. Mark recruited ecologist Professor Mike Bull from Flinders University to help with the research. Since that time, numerous research hours and funds have been dedicated to characterising the pygmy blue tongue and it is now one of the best known lizards in Australia.
The pygmy blue tongue is found in 30 locations across the Adelaide plains. At about 15cm long, it is the smallest member of the blue tongue lizard family. The lizards live in holes in the ground that they take over from trapdoor spiders. Despite their name, they don’t have a blue tongue — it’s actually pink —although the skin lining their mouth is bluish in colour. This is a “bluetongue” because it shares important characteristics with the larger bluetongue species, such as enlarged jaw muscles and crushing back teeth, a short tail and legs, and an elongated body.
Male and female lizards lead solitary lives and are highly territorial. They only share burrows when females have young, and males generally only leave their burrows for extended periods to seek mates in October and November each year. They are vulnerable to predation at this time, which is probably how that one surprising but highly significant, pygmy blue tongue ended up in the belly of an unlucky snake.
Mark and Professor Mike Bull are continuing their research on the pygmy blue tongue lizard with support from an Australian Research Council Linkage Grant.