Condamine earless dragon conservation

Hidden Vale researchers work closely with other groups to help conserve the Condamine earless dragon (Tympanocryptis condaminensis) which is a small, endangered agamid lizard endemic to Queensland and restricted to the Condamine floodplain and surrounding areas, west of Toowoomba. Like others in the genus from Australian eastern grasslands, their habitat has been highly modified by agriculture and major road and rail projects. It was estimated that less than 5% of original habitat remained in 2016 when a conservation advice was issued, and the situation has only worsened since then. This species is one of Australia’s most imperilled reptiles, with almost no protected or unmodified habitat, yet despite these challenges, it has managed to persist on road verges and in cropped lands. This persistence is not reason for complacency, as the species is highly susceptible to imminent extinction.

T. condaminensis was recently ranked as the 13th most likely reptile species to become extinct by 2040, with the Tympanocryptis genus representing a quarter of the 20 most imperilled reptiles (Geyle et al., 2021). In a priority threat management report in 2016 the Condamine earless dragon was identified as one of the most at risk species of fauna in the brigalow belt region, facing a greater than a 50% chance of functional loss, and that given it is not feasible to halt all threatening processes that impact biodiversity persistence, strategic species-specific management responses are required (Ponce Reyes et al., 2016). Condamine earless dragons inhabit native grasslands which have been heavily modified by agriculture, leading to decline of almost all of their habitat. It only persists on road verges and privately owned agricultural land, which is a very precarious situation, making the species highly susceptible to imminent extinction.

The Victorian grassland earless dragon (T. pinguicolla) was believed to be extinct for 50 years until 2023, when they were rediscovered and rescued into the safety of captivity, which was expediated by proactive conservation actions taken years prior to establish an ex situ population of the Canberra grassland earless dragon (T. lineata).

Threats

The threats to this species are largely driven by human activity and environmental changes. This species once inhabited the native grasslands of the cracking clay soils of the Darling Downs, which have been significantly reduced by agricultural expansion for cropping, and impacted by agricultural practices such as tilling, spraying with insecticides and herbicides, monoculture cropping, and expansion onto road verges. This is likely to have resulted in less-than-suitable areas for foraging, shelter, and breeding. As habitats become more fragmented, the species has been left with small, isolated populations that are at a higher risk of inbreeding, genetic decline, and local extinctions.

The Condamine earless dragon persists along grassy road verges. These areas are especially dangerous because of the high risk of road mortality. The typical agamid behaviour, such as basking in sunny spots along roads, increases the likelihood of being hit by vehicles. This threat is compounded by the fact that the species is already living in isolated, vulnerable pockets of habitat, where the loss of even a small number of individuals can have a significant impact on population survival.

Conservation

In 2016, the Threatened Species Committee provided a Conservation Advice for Tympanocryptis condaminensis based on the fact that it has a restricted geographic distribution that is precarious due to severe fragmentation and continuing decline of extent and quality of habitat (Threatened Species Scientific Committee, 2016). This document acknowledged that the primary conservation objective was to increase the abundance and distribution of the Condamine earless dragon by maintaining and rehabilitating known and potential habitat. Eight years later, there has been no improvement in habitat extent or quality, but there has been an increased survey effort over the last two years.

In 2023 a Draft National Recovery Plan for four species within this genus for southern Australia was prepared (Department of Climate Change, 2023). These species are all close analogues for T. condaminensis. Strategy 7 recommends captive breeding as a critical recovery action, and Strategy 8 recommends research to contribute to the recovery of the genus.

Research

Report a sighting

References

Department of Climate Change, the Environment and Water,. (2023). Draft National Recovery Plan for Four Grassland Earless Dragons (Tympanocryptis spp.) of Southeast Australia.

Geyle, H. M., Tingley, R., Amey, A. P., Cogger, H., Couper, P. J., Cowan, M., Craig, M. D., Doughty, P., Driscoll, D. A., Ellis, R. J., Emery, J.-P., Fenner, A., Gardner, M. G., Garnett, S. T., Gillespie, G. R., Greenlees, M. J., Hoskin, C. J., Keogh, J. S., Lloyd, R., . . . Chapple, D. G. (2021). Reptiles on the brink: Identifying the Australian terrestrial snake and lizard species most at risk of extinction. Pacific conservation biology, 27(1), 3-12

Ponce Reyes, R., Firn, J., Nicol, S., Chadès, I., Stratford, D., Martin, T., Whitten, S., & Carwardine, J. (2016). Priority Threat Management for Imperilled Species of the Queensland Brigalow Belt.

Threatened Species Scientific Committee. (2016). Conservation Advice: Tympanocryptis condaminensis.