Scientists use DNA from poop to save the world’s rarest marsupial

New research from Edith Cowan University (ECU) may provide an important boost for efforts to save the world's rarest marsupial. The Gilbert's potoroo, a critically endangered species found only in Western Australia, has 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 help secure the species' future. "We are looking to recover the species through translocations, which is moving organisms from one location to another to create an insurance population in case anything was to happen in their existing populations," School of Science PhD student Rebecca Quah explains. "In doing that, one of the challenges was trying to determine what they are eating and where those resources can be found. Mycophagus -- or fungi-eating mammal diets are quite hard to study because a lot of fungi remain undescribed." To investigate the potoroo's diet, researchers used environmental DNA (eDNA) metabarcoding on scat (faeces) samples. The technique is becoming increasingly popular in wildlife research because it allows scientists to study animals without disturbing them. "Traditionally, researchers would go through undigested material in scats to study animal diets, but trying to identify fungal spores remained a challenge," Ms. Quah said. "This research used a molecular technique, known as eDNA metabarcoding to decipher what animals are eating. It's a non-invasive way of studying diet and all you need are fresh scats from the environment." The team also examined whether the diets of more common fungi-eating mammals overlapped with the Gilbert's potoroo. Researchers focused on species that historically shared the same habitats. "We examined quokka, quenda and bush rat scats and found that there was some overlap in the diet of the four mammals, and that habitat use between the quokka and potoroo were also really similar," Ms. Quah said. "Based on our results, we recommend focusing on areas where all three species persist together as an indicator of suitable food, or habitat, for future potoroo translocation sites." Gilbert's potoroo was once believed to have disappeared entirely before being rediscovered in 1994. Since then, conservation teams have tried several approaches to increase the population. "Soon after their rediscovery, breeding them in captivity was tried, but that didn't work out, particularly because of how picky they are with their food resources," she said. "This is...