Using Environmental DNA to protect endangered wildlife
For the first time, Australian scientists have shown that environmental DNA (eDNA) can be used to detect the presence of an endangered bird species simply by collecting a cup of water from the pools where they drink. eDNA has already emerged as a powerful tool to trace rare and threatened aquatic species, but had not yet been applied to the detection of threatened terrestrial species.
A team of researchers from Charles Darwin University (CDU), The University of Western Australia, and the Northern Territory Department of Environment and Natural Resources (DENR), developed a genetic probe that targets the eDNA of the endangered Gouldian finch (Erythrura gouldiae).
The Gouldian finch is a rainbow-coloured grassfinch endemic to the savanna woodlands of northern Australia. The finches are found in small groups across the vast region so it is very difficult to track changes in the population from year to year.
Pastoralism and the timing and intensity of fires has been linked to the decline in the finch’s numbers, most likely due to the reduced availability of the grass seeds that form the major part of their diet.
CDU Professor Karen Gibb, who led the study, said the eDNA test had the potential to increase knowledge of the distribution and habitat use of Gouldian finches: “This is essential information to guide land management decisions that will assist the recovery of wild populations.”
When Gouldian finches drink at waterholes, they leave traces of their DNA behind that can now be detected after they’ve flown away. The researchers developed a two-in-one eDNA qPCR test that recognises and makes multiple copies of a specific region of mitochondrial DNA found in Gouldian and related finches as well as a species-specific probe to detect only Gouldian finch DNA.
Scientist Brydie Hill, from DENR, explained how this relatively simple sampling method can help: “Land managers, such as the Jawoyn Rangers, can then map where the finches occur across the landscape and compare it with their fire management to see how their activities are benefitting the recovery of Gouldian finches.”
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