A species redefined
The Grassland Earless Dragon lizards (Agamidae: Tympanocryptis) of south-eastern Australia have long been of conservation concern and is listed as Endangered but there have been ongoing taxonomic uncertainties. This means that there may be undocumented species within the Grassland Earless Dragon. Scientists at Museums Victoria, along with researchers at the University of Canberra and South Australian Museum, were asked by the National Recovery Team for these dragons to look at this problem. A resolution of the ongoing taxonomic uncertainties in this group would allow managers to develop targeted conservation actions.
This collaborative research team, in a paper published in Royal Society Open Science (2019), split the single species of Grassland Earless Dragon into four. This means that the distribution of the Victorian Grassland Earless Dragon (Tympanocryptis pinguicolla) is now restricted to the Melbourne region. The last confident sighting of this species was 50 years ago in 1969!
The Victorian Grassland Earless Dragon is a habitat specialist species known only to occur in the native grasslands on the Victorian basalt plains around Melbourne. Historically known from several locations around Melbourne, including Sunbury, Maribyrnong River (then called "Saltwater River") and as far west as the Geelong area up until the late 1960s.
Although there is little information available about the ecology of this species, it was described by Lucas & Frost in 1894 as:
"Inhabiting stony plains and retreating into small holes, like those of the 'Trap-door Spider,' in the ground when alarmed. (McCoy, l.c.). Often met with under loose basalt boulders."
The last confirmed sighting of the Grassland Earless Dragon in Victoria was from the Geelong area in July 1969.
Is this mainland Australia's first reptile extinction?
Globally, 31 reptiles have been listed as extinct or extinct in the wild on the IUCN Red List (the global authority on the status of species) There have been two skink and one gecko species from Christmas Island, which is an Australian territory, recorded as Extinct or Extinct in the Wild. However, until now there have been no recorded reptile extinctions on the Australian mainland.
Following taxonomic revision by Dr Jane Melville and her collaborators, the Victorian Grassland Earless Dragon is now restricted to the Melbourne region. This means that the last confident sighting was in 1969, near Geelong, and the last animal confirmed with collection of a museum specimen was 1967. Researchers assessed the possibility that the Victorian Grassland Earless Dragon is extinct in 2019 using sighting data but results were equivocal as to whether it is still in existence (extant) or extinct.
There are a number of factors that still leave open the possibility that the Victorian Grassland Earless Dragon is not yet extinct. There are still some remaining habitat areas that have not been surveyed and this cryptic species is small, secretive and hard to find. These factors emphasise the immediate imperative for continued surveys to locate any remaining populations of the Victorian Grassland Earless Dragon.
Zoos Victoria - Fighting Extinction
It is difficult to develop targeted conservation action without species distribution information, a critical step in the conservation of this species involves surveying probable locations of dragons based on suitable habitat in Victoria.
The small number of Grassland Earless Dragons preserved in the collections of Museums Victoria are now a crucial source of information on the historic distribution of the species. This information can help predict suitable habitat in Victoria.
Zoos Victoria is leading efforts to save the Grassland Earless Dragon, with its Fighting Extinction program. Staff at Zoos Victoria work alongside expert ecologists and local communities to foster widespread community support for and knowledge of this dragon, and have been conducting surveys in potential habitats and working with communities to find further target sites that may re-ignite hope of re-discovering the species in Victoria.
Zoos Victoria's efforts have focussed on confirming the presence of the Victorian Grassland Earless Dragon, using various methods such as habitat mapping, camera trapping and active searching. The research team have concentrated on the identification of previously unsurveyed areas and assessing these for habitat structure, invertebrate abundance and the potential for supporting earless dragons. In 2018 a series of mini-pitfall traps were deployed at two primary locations in Little River. Unfortunately, no earless dragons were detected during the survey and few lizards of any species were caught despite indications of suitable habitat structure and sufficient invertebrate fauna to support them.
Zoos Victoria is not giving up yet and is committed to continuing the search, with additional sites for pitfall trapping already identified for further survey work. Reptile Keepers at Melbourne Zoo will also be developing husbandry techniques and providing husbandry support to the National Recovery Team with individuals from the ACT and NSW grassland earless dragon species.