Two threatened marsupials are being reintroduced to the Shark Bay World Heritage area in order to advance species conservation and ecosystem restoration. A new study from Edith Cowan University (ECU) confirmed that the presence of fungal food resources is important for supporting this effort.The study published in the journal Ecosystems and led by Edith Cowan University PhD Candidate Rebecca Quah, took place at six sites across Western Australia and the Northern Territory, including Dirk Hartog Island in Shark Bay. Scientists used DNA technology to decipher what fungi were palatable to boodies (burrowing bettong) and woylies (brush-tailed bettong) marsupials. Then verified that key food resources were available to support new populations on the island.What makes these bettongs special is that they spend many of their waking hours, digging through soil, either in search of food or burrowing for shelter in the case of boodie. “Amongst the dietary items these bettongs eat is fungi, a feeding habit known as mycophagy. As they dig and feast on fungi, they are doing something crucial for the landscape – turning over soil and spreading fungal spores, which helps to keep plants and the wider ecosystem healthy,” said Quah.
Once native, now no more
Following the successful removal of livestock and feral cats, the island is now in recovery, with scientists introducing boodies and woylies
Dirk Hartog Island was not always this way. Between the 1860s and 2009, pastoral activity dramatically changed the landscape on the island and, coupled with the effects of predation by introduced feral cats, at least 11 native species disappeared including boodie, woylie and Shark Bay bandicoot. The felines were brought over by the 19th-century European pastoralists and lighthouse keepers as domestic pets and for vermin control. Over time, some cats escaped or were allowed to breed, eventually establishing a feral population that decimated native marsupial and bird populations.Following the successful removal of livestock and feral cats, the island is now in recovery, with scientists actively reconstructing its faunal assemblage. “Prior to the boodie and woylie reintroductions, we needed to know if the cryptic fungal resources these species depend on persisted through the landscape changes on the island,” said Quah.Fungi spend most of their lives hidden underground as networks of thread-like structures. “The fruiting bodies we see as mushrooms are only the tip of the iceberg, and some fungal fruiting bodies never show themselves above ground at all.” Traditional methods of studying fungal communities posed many challenges; however, molecular technology has changed everything.Instead of looking through faecal and gut content to manually identify undigested food material, the team made use of DNA technology. “First, we analysed DNA from the faeces of boodies and woylies at five sites across Western Australia and the Northern Territory,” Quah said. Just like fingerprints, the DNA sequences help scientists to identify each fungal species that has been eaten by the bettongs.“Then, we collected soil samples from dominant habitat types across Dirk Hartog Island and similarly analysed the DNA in the soil, which let us know what fungi were present on the island”.Finally, they compared the two datasets. The results showed the island is home to 75 different types of fungi that produce larger, more visible fruiting bodies that animals are likely to go for.“More importantly, approximately 50 per cent of the fungi that boodies and woylies consume at other sites are present on Dirk Hartog Island, including a truffle-like species from the Pezizaceae family, which was most abundant in both boodie and woylie diets, as well as on the island.”
Improvement in fungal biodiversity
Boodies and woylies are not just passengers in the ecosystem, but as they consume and defecate fungal material, their movement through habitats facilitates fungal dispersal. “We identified that the majority of boodie and woylie diets consist of ectomycorrhizal fungi, which are important in plant nutrient uptake, carbon cycling, and boosting overall ecosystem productivity,” said Quah.“Some fungi, in particular, those that fruit underground, have also evolved to rely heavily on animals like bettongs for dispersal by developing an aromatic characteristic to attract these animals,” she added. Without boodies and woylies on the island, the dispersal of these fungi would be limited and would have a negative impact on plant communities.“We are hopeful that the reintroduction of these bettongs will not only contribute to their conservation, but also restore ecological functions that have been largely absent for decades on Dirk Hartog Island,” said Quah.
