Is There Mush-room for Bettongs on Dirk Hartog Island? Environmental DNA Assessment of Food Resource Availability for Fauna Translocations

Abstract

Conservation translocations require careful assessment of dietary resources to ensure population viability. Here, we used environmental DNA metabarcoding to characterise fungal assemblages across three major habitat types on Dirk Hartog Island, Western Australia, prior to the planned reintroduction of two threatened mycophagous species: the boodie ( Bettongia lesueur ) and woylie ( Bettongia ogilbyi ). We detected 243 fungal ASVs, of which 75 represented taxa that are likely to produce macroscopic fruiting bodies accessible to mycophagous mammals. Ectomycorrhizal fungi dominated all habitats, with Pezizaceae being the most abundant family—a pattern consistent with known dietary preferences of both species across multiple Australian locations. Fungal community composition differed significantly among habitat types, with birrida (saltpan), dwarf scrub, and shrub-steppe each supporting distinct assemblages. Comparative analysis with recent dietary studies revealed approximately 50% overlap between the island’s fungal communities and boodie and woylie diets, indicating suitable resource availability. While potential dietary overlap (25–33%) exists between species, the island’s size and spatial distribution of fungal resources suggest competition is unlikely to limit initial population establishment. These findings demonstrate that Dirk Hartog Island possesses a diversity of fungal resources suitable to support both species, with birrida habitat recommended as preferential release sites following rainfall events to maximise foraging success.

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