Animals leave DNA traces of their presence in hair, skin, urine, faeces, sperm and eggs that are shed into their surrounding environment. This DNA can be found in the environment for a short time even after visible traces have disappeared, and is called eDNA.
This project showed, for the first time, that eDNA can be used to detect the presence of an endangered bird species simply by collecting a cupful of water from the pools where they drink.
The research developed a genetic probe that targets and identifies eDNA of the endangered Gouldian finch (Erythrura gouldiae), a rainbow-coloured grassfinch endemic to the savanna woodlands of northern Australia.
Gouldian finches live in small and mobile groups, making them difficult to find using standard survey methods. This new eDNA test for Gouldian finches will help the Northern Territory Government in their regional wildlife surveys.
Gouldian finches drinking at a waterhole in the Northern Territory. Photo: NESP Northern Australia Hub.
The Gouldian finch test is a single-species detection test. This project also aimed to develop a multi-species approach – known as eDNA metabarcoding – to detecting terrestrial animals in northern Australia. Metabarcoding allows the detection of multiple species within a single sample of water, making these tests cheaper and more efficient for surveying general biodiversity.
This project successfully identified species’ DNA from ‘mock’ communities of birds and mammals, using a DNA library. However, the volume of water sampled (250 mL) was insufficient to collect enough DNA when tested in the field.
Given the logistical constraints of collecting and transporting large volumes of water in northern Australia for metabarcoding analysis, single-species detection tests (such as the one developed for Gouldian finches) may be the preferred approach if the goal is to detect particular species of interest – such as threatened or invasive species.
Overview of the eDNA process. Click to enlarge.
The Northern Australia Environmental Resources Hub addressed key research questions to come up with practical, on-ground solutions to some of the north’s most complex environmental challenges. A transdisciplinary research approach has been at the heart of the hub. Integrating key research users – policy-makers and land managers including Traditional Owners and ranger groups – into the co-design of research projects has led to rapid uptake of research outcomes into land management practices and decision-making. The hub has produced this wrap-up video outlining these impacts from the perspectives of research users.
This website describes the eDNA approach and features a game for kids to test their knowledge of Gouldian Finch eDNA. Developed in partnership with Inspired NT.
Day K, Campbell H, Fisher A, Gibb K, Hill B, Rose A & Jarman SN. (2019). Development and validation of an environmental DNA test for the endangered Gouldian finch. Endangered Species Research 40:171-182. https://doi.org/10.3354/esr00987
This project was led by Professor Karen Gibb from Charles Darwin University and Dr Alaric Fisher from the Northern Territory Department of Environment, Parks and Water Security.
Professor Gibb and Dr Fisher were being assisted by researchers from Charles Darwin University and the NT Department of Environment, Parks and Water Security.
This project was completed in December 2021.