Key points
- The Tjakuṟa is a threatened species of cultural significance to Aṉangu, the Traditional Owners of Uluṟu-Kata Tjuṯa National Park.
- The project Molecules in the sand: eDNA and the Biology of the Tjakuṟa uses Indigenous Knowledge and environmental DNA (eDNA) technology.
- eDNA extracted from soil, air and scat samples can reveal how many Tjakuṟa occupy a single burrow, their diets and more.
In Central Australia, the Tjakuṟa (Great Desert Skink, Liopholis kintorei) is a culturally important species for Tjukurpa – the Aṉangu law of caring for each other and the land that supports them.
Leroy Lester is a Traditional Owner and Aṉangu Engagement Officer.
“Great Desert Skink, Tjakuṟa, is part of a creation story that comes through here, through the park. It’s very important for keeping that connection to the land, for land management and keeping those stories,” Leroy said.
Tracking the Tjakuṟa
Dr David Thuo studied cheetahs in Kenya before moving to Australia to take up a postdoctoral research position at our Australian National Wildlife Collection to work on this species.
“The Tjakuṟa is a large lizard that lives in multi-tunnelled communal burrows in the arid zones of central and western Australia,” Thuo said.
“The species is classified as Vulnerable to extinction due to its continuing decline in range and numbers, vulnerability to cats and foxes, and changes in fire regimes.”
It is listed as a priority species under the Threatened Species Action Plan 2022-2032.
Thuo has worked closely with Aṉangu Rangers and the Central Land Council’s Tjakura Rangers to learn more about the species.
“We rely on Aṉangu Traditional Knowledge to locate Tjakuṟa burrows, estimate burrow occupancy and identify predator tracks,” Thuo said.
“I collect soil samples and air samples, burrows and scat samples from the Tjakuṟa’s communal latrines. I analyse the eDNA in these samples to count the number of Tjakuṟa present and find out what they eat.”
Extracting eDNA from soil and scats is a non-invasive method that respects the species and aligns with Aṉangu values. In fact, Thuo can study the Tjakuṟa without even needing to see them.
A varied diet
Thuo’s analysis of DNA extracted from scats, Metabarcoding clarifies the diet of the elusive and vulnerable Australian tjakura (Great Desert Skink, Liopholis kintorei), confirmed Tjakuṟa are omnivores. They eat a wide variety of plants and invertebrates as well as small vertebrates.
“The most abundant Tjakuṟa foods we detected were fruit flies, beetles, mosquitos, termites, spiked mallow, bush tomatoes and wild turnip,” Thuo said.
The researchers found Tjakuṟa diets did not differ significantly across seasons or between different age groups.
This work demonstrates the success of eDNA techniques for studying culturally important species without disturbing them.
Bringing the past into the present
During a recent survey, a deceased Tjakuṟa was respectfully donated to the Australian National Wildlife Collection, with the permission of Aṉangu. While its passing was unfortunate, the specimen will provide vital genetic data for future research.
Comparing DNA from this modern specimen with older specimens collected in the 1960s and held in a museum in Darwin will show how Tjakuṟa populations have changed over time and responded to environmental changes.
The ability to do this is thanks to our cutting-edge techniques for working with historical DNA, including methods that explore how the environment affects genetic changes.
These techniques can reveal how an animal’s environment influences its genetic expression. This approach, described as 'epigenetic time travel,' opens new doors in understanding how species adapt—or struggle to adapt—to changing climates and habitats.
This project also sequenced the first complete mitochondrial genome of the Tjakuṟa (GenBank: PP957932).
“The genome is an important resource for genetic studies and a valuable addition to the growing database of skink genomes now available for research,” Thuo said.
Leading into long term monitoring
The results of the research will have lasting impacts, not just for the Tjakuṟa.
“Tjakura is guiding us in how to look after the land. He is a local here. Tjakuṟa is here because of the creation story," Leroy explained.
“The data can guide where and when to carry out Indigenous fire management, inform future translocations of Tjakuṟa to increase genetic diversity and resilience to environmental changes, and support monitoring of other Tjakuṟa populations across the desert,” Thuo said.
“An added benefit is that we’ve built capacity to study other Australian skinks.”
The project is being led by Parks Australia and CSIRO in collaboration with Aṉangu Traditional Owners, the Uluṟu-Kata Tjuṯa National Park Board of Management, the Australian National University and The National Parks Conservation Trust (with support from the Wettenhall Environment Trust and Foundation for Rural & Regional Renewal). It’s further supported by the Central Land Council’s Tjakura Rangers, Muṯitjulu Community Rangers and the Muṯitjulu Aboriginal Corporation.