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Curbing global wildlife population declines will necessitate the protection of their habitat, and subsequent robust baseline information about wildlife that use and occupy it. Collating such information, however, remains a challenging and costly endeavour. Little did we know that traces of wildlife presence float in the air and can be detected through traces of DNA.Here, we deployed samplers to test the applicability of collecting airborne eDNA for the detection of a threatened species, the koala, and its co‐occurring terrestrial mammalian community.We develop a novel species specific qPCR assay to detect the presence of koalas and applied this in concert with a meta‐barcoding approach to detect the co‐occurring mammalian community.Through sampling of airborne particles, we successfully detected koala presence accurately to habitat patch level, alongside 16 unique taxonomic assignments, successfully assigning 11 of these to species level including detections belonging to the wallaby, antechinus, members of possum family and invasive species such as foxes, domestic dogs and hares.Synthesis and applications: We demonstrate the potential of airborne eDNA for the detection of threatened terrestrial wildlife and their surrounding ecological community under natural conditions. With achievable optimisations we detail how airborne eDNA may be applied for the management and monitoring of threated species for enhanced conservation efforts. [ABSTRACT FROM AUTHOR]

Given the high proportion of Earth's ecosystems already anthropogenically modified, especially through clearing, it is critical we determine whether species can persist outside of their primary habitat as a means of ensuring population persistence in the remaining landscape. The koala (Phascolarctos cinereus) has been heavily impacted by habitat loss through clearing, and recently upgraded to endangered across its eastern distribution. It is timely to understand what variables may influence the occurrence of koalas in secondary habitat, which can then guide conservation efforts. We surveyed 959 sites with detection dogs to determine the occurrence of koalas through the presence of scats. Using GLMMs, we accounted for environmental and anthropogenic variables that may influence koala occurrence, meanwhile focusing on the use of secondary eucalyptus forests at multiple spatial scales (250, 500, 1500 m radii). Overall koala occurrence was negatively associated with secondary eucalyptus forests compared to primary forests, while there was no effect of total forest area present at any scale. However, we found interactive effects between secondary forest and (1) distance from the closest major road at the smallest landscape scale (250 m radii) and (2) water area at the larger landscape scales (500 m, 1500 m radii). This suggests that occurrence of koalas in secondary forests are predicted to increase when the distance to major roads, and the water area, increase. While protecting primary eucalyptus forests should always be a prioritisation for the conservation of koalas, our results emphasize the important role that secondary eucalyptus forests can play in conservation, as long as these are carefully considered in the landscape context to maximise restoration investments. [ABSTRACT FROM AUTHOR]

Fragmentation of habitat is a major threat across a wide range of taxa. Subsequent effects include reduced population sizes and isolation of populations. Both can have detrimental consequences for populations as they increase the risk of genetic erosion. While it is critical to prevent and, if required, reverse genetic erosion, we often lack adequate data to assess whether and how much genetic erosion has occurred. Here, we present a genetic monitoring study where we investigated changes in genetic diversity and genetic patterns in a threatened, specialist mammal, the koala (Phascolarctos cinereus). Our study population inhabits an increasingly fragmented landscape and has experienced a sharp decline in population size within the past three decades. We used 1038 single nucleotide polymorphic loci (SNPs) to compare measures of genetic diversity between samples collected in 2018 and in 2006 (two generations prior) and investigated simultaneous changes in the environment. We found a decline in both heterozygosity and effective population size (Ne), and an increase in sub‐structuring, average relatedness, and inbreeding (FIS) alongside an increasingly threatening and more fragmented environment. Given the extent of genetic erosion in only two generations, we urge consideration for the implementation of mitigation measures for this population and for threatened populations in similar conditions. Our study further emphasizes the importance of effective management of at‐risk populations including monitoring of genetic erosion. [ABSTRACT FROM AUTHOR]