New research from Edith Cowan University (ECU) could provide an important boost to efforts to save the world’s rarest marsupials.
The Gilbert Potoroo is an endangered species found only in Western Australia, with fewer than 150 animals left in the wild. Scientists from ECU and the Department of Biodiversity, Conservation and Attractions (DBCA) are working together to better understand what the small marsupials eat, so conservation teams can identify suitable new habitats and secure the future of the species.
“We aim to recover species through translocation, where we move organisms from one place to another, creating an insurance population in case something happens to an existing population,” explains Rebecca Quar, a PhD student in the School of Science.
“One of the challenges then was to determine what they eat and where those resources can be found. Studying the diet of mycophagus, or fungi-eating mammals, is very difficult because many fungi have not yet been described.”
Researching diet using fecal and urine DNA
To investigate the potoroo’s diet, the researchers used environmental DNA (eDNA) metabarcoding of fecal (fecal) samples. This technique is becoming increasingly popular in wildlife research because it allows scientists to study animals without disturbing them.
“Traditionally, researchers looked at undigested material in feces to study an animal’s diet, but identifying fungal spores remained a challenge,” Quah said.
“In this study, we used a molecular technique known as eDNA metabarcoding to decipher what the animals were eating. It’s a non-invasive way to study diet, and all it takes is fresh feces from the environment.”
The researchers also investigated whether the diets of more common fungi-eating mammals overlap with Gilbert Potoroo. The researchers focused on species that historically shared the same habitat.
“We looked at quokka, quenda and woodrat faeces and found that there is some overlap in the diets of the four mammal species, and that the habitat use of quokkas and potoroos is also very similar,” Kua said.
“Based on our results, we recommend focusing on areas where all three species persist together as indicators of suitable food or habitat for future potoro translocation sites.”
Thought to be extinct but rediscovered
Gilbert’s Potoroo was thought to be completely extinct until it was rediscovered in 1994. Since then, conservation teams have tried several approaches to increase the population.
“Shortly after their rediscovery, attempts to breed them in captivity were unsuccessful, especially because they are very picky about food resources,” she said.
“This is why wild-to-wild translocation is so important. In 2015, wildfires destroyed 90 per cent of the core potoroo habitat in Two People’s Bay, home to the only natural population of Gilbert’s potoroo. Fortunately, insurance populations had been established by the DBCA in fenced enclosures at Bald Island and Waychinicup National Park.”
DBCA researcher Dr Tony Friend said researchers were now looking for other suitable locations on the mainland to establish additional populations. The species is now spread to four locations, including two islands off the coast of Western Australia.
“Searching for new translocation sites is an important next step in restoring the Gilbert potoroo from the brink of extinction. This paper shows that examining the mammalian mycophagy associated with the potoroo may help decide where to establish new populations,” said Dr. Friend.
Why fungi-eating mammals are important
Mr. Quah’s extensive doctoral research focuses on the conservation and migration of fungi-eating mammals, which play a critical role in maintaining healthy ecosystems.
“Fungi-eating mammals are ecosystem engineers, seeking out fungi to aid soil metabolism and acting as vectors to spread fungal spores.
“Fungi have several ecological functions, including mutually beneficial relationships with plants, so fungi-eating mammals are critical to maintaining healthy ecosystems.
“Unfortunately, many of Australia’s mammals are at risk of extinction due to predation by non-native cats and foxes. That’s why it’s important that we do everything we can to protect our native wildlife, and translocation is one important way to achieve that goal.”
