Understanding genetic structure and diversity is critical to tracking the potential of isolated island populations to persist and their capacity to adapt to environmental change. We investigate the population genetics of the South Australian glossy black-cockatoo, Calyptorhynchus lathami halmaturinus, that has been confined to Kangaroo Island for at least 60 years. By the early 1990s the population had declined to a few hundred individuals, before management allowed some recovery, but it then suffered a major loss of habitat in the 2019-20 black summer bushfires.
We analysed SNP data generated from pin feathers collected from 84 glossy black-cockatoo nestlings from across Kangaroo Island during two breeding seasons, focussing on population structure, genetic diversity, inbreeding and relatedness. Genetic differentiation between flock regions is statistically significant but very weak, indicating that there is sufficient movement of individuals for gene flow to occur across the population. We also conclude that the Kangaroo Island population has retained moderate levels of diversity and allelic richness. As expected from field observations, spatial autocorrelation confirms that there is stronger than random relatedness amongst nestlings in nesting clusters. A conservative estimate of Ne of 122 is above the 100 individuals sometimes suggested as the minimum required to avoid inbreeding depression in the short term.

Ex situ management of threatened species has long played a part in many broader conservation initiatives for both species and ecosystems and can provide critical support in emergency situations. For novel species that have never been held in an ex situ environment, or where very little information on ex situ management exists, this paucity of knowledge itself represents a conservation risk. In these instances, where ex situ tools are being considered as part of a wider conservation strategy, a crucial first step is the development of husbandry knowledge and skills for the species, as without these it is difficult to fully evaluate the potential effectiveness of further ex situ management actions. To this end, exploring the need and potential capacity of an ex situ population of the Endangered Mallee Emu-wren (Stipiturus mallee) is a key recovery objective for the species, and has been the focus of many years of scoping, research, and on-ground works by the Threatened Mallee Bird Steering Committee, culminating in the 2023 wild-to-captive translocation of ten Mallee Emu-wren into Monarto Safari Park.

Here we discuss the results of the ex situ program thus far; including the development of husbandry techniques, facilitation of the first ever successful breeding of Mallee Emu-wren in captivity, important learnings for the biology of the species, and next steps towards supporting in situ wild conservation. The local extinction of Mallee Emu-wren in 2014 was a devastating loss for South Australia, but through rigorous science and dedication, the early successes of our project provides hope that we will once again see this enigmatic species return to the State.

Tidal, diel and lunar cycles have been shown to influence fish behaviour including feeding and reproduction in subtidal habitats. While fish behaviour in intertidal habitats is less well studied, they are known to be used by many fish species as nursery areas, due to inherent characteristics that provide benefits to juvenile fish. Despite their relative safety in comparison to subtidal environments, predation in intertidal habitats is known to occur; however, there is little research into how temporal cycles influence predation rates. This project developed a novel method to monitor predation within intertidal areas to investigate how fish predation varied over different temporal cycles. These baited stations (termed e-pops) utilise electronic systems to accurately measure when predation events occur during the tidal cycle. Over the course of a lunar cycle, subtidal and intertidal predation was monitored using e-pops. The results indicated that intertidal and subtidal predation rates were not statistically different from each other; and there were no significant differences in predation between diurnal and nocturnal conditions. There was however a significant interaction between depth (subtidal or intertidal) and the diel phase (diurnal or nocturnal). Significant differences were found between stages of the lunar cycle (new, first quarter, full, and last quarter moons), however post-hoc analysis showed that the first new moon was different to each subsequent lunar phase, including the next new moon. This difference was likely attributable not to the lunar cycle itself, but to fish becoming habituated to the food source provided by the e-pops. Habituation of fish to a new food source can occur rapidly and can then override the influence of other temporal factors on fish behaviour. It is therefore important to understand the ecology and species composition of the study environment, including to minimise or account for habituation during experiments.

Invasive mammalian predators pose severe ongoing threats to biodiversity. Feral cats (Felis catus) have been implicated in 26% of bird, mammal and reptile extinctions worldwide. In Australia, predation by feral cats and red foxes (Vulpes vulpes) is a significant driver of mammal extinctions, with ground-dwelling critical weight range (CWR) mammals (35-5500g) most at risk. Understanding how feral cats impact wildlife populations, and under what environmental conditions co-existance might be possible where cat eradication is unachievable, remains a crucial conservation knowledge gap.

We aimed to understand the population dynamics of long-nosed potoroo (Potorous tridactylus trisulcatus), a CWR Australian marsupial, on fox-free French Island during a cat eradication program. We trapped 33 sites for three consecutive winters to track changes in potoroo population dynamics, across a gradient of fragmentation and a mosaic of habitat types. Concurrently, cat numbers declined as a result of sustained control efforts. We recorded a substantial increase in potoroo density Island-wide, including at sites with low vegetation cover, where habitat was previously deemed unsuitable/risky for potoroos. Alongside population growth, potoroos have declined in body condition, possibly reflecting that carrying capacity has been exceeded following reduced predation pressure by cats.

Given the difficulties managing impacts on native wildlife by feral cats, our study highlights that native prey populations can benefit substantially from reduced predator numbers, prior to achieving eradication. Such findings can be applied to conservation decision-making, recognising that conserving and restoring potoroo populations will aid ecosystem restoration due to their functional roles of digging and spreading hypogeal fungi.

The pygmy bluetongue lizard is nationally listed as endangered and restricted to patches of native grassland in the mid-north region of South Australia. Without intervention, climate change is predicted to drive pygmy bluetongues to extinction within the next 50 years. At present, there are no established methods for estimating the size of the known pygmy bluetongue populations, or to reliably detect the onset of any declines. Here we present work undertaken by Nature Foundation to generate a regional pygmy bluetongue population estimate and monitor the population over time.

GIS software was used to randomly distribute monitoring plots across the area of suitable habitat at Nature Foundation’s Tiliqua nature reserve. In line with best practice, the distribution was defined through a power analysis which identified the optimal size and number of plots needed to reliably detect population changes. These data were extrapolated across the remaining suitable habitat to generate an initial population estimate. Further, a Generalised Additive Model was developed using multiple habitat variables to provide a more robust population estimate. The method was also implemented at two additional sites, in the nearby town of Burra.

The previous population estimate for the species of 5,000 individuals across 10 known populations was established in 2002. Since then, more than 30 populations have been discovered. Our method suggests ~ 6,000 individuals could be present across just the three populations we sampled. Our new method will help to standardise surveys of known populations, and thus generate an accurate population estimate for the species. When used in long-term monitoring programs it will enable the accurate detection of population declines, promoting timely intervention that increases the chances of species survival.

Valuable fossil and historical occurrence data are absent for many Australian endemics, resulting in uncertainty in restoration programs. Environmental DNA (eDNA) techniques provide a promising alternative to fill gaps left in fossil records and confirm species past presence on landscapes. We developed the first species-specific qPCR assay to provide a standardised method for detecting the numbat (Myrmecobius fasciatus), an endangered species, in sedimentary eDNA. We validated this assay using hair samples collected from a captive enclosure then assessed the assay on environmental soil and sediment samples taken from caves and crevices at Newhaven Wildlife Sanctuary. We will present presence/absence results for numbat DNA across a hierarchy of sampling levels (qPCR replicate, environmental replicate, site). More generally, we provide a non-invasive and highly sensitive tool for capturing numbat historic presence at the edge of its past range in a previously unsampled location. This will help increase the success of future translocation programs and prevent biodiversity loss.

The height at which climbing lizards perch involves trade-offs between positive exposures (visibility to conspecifics, thermoregulation) and negative exposures (predation). In this study, we explore the perching preferences of the Australian bearded dragon (Pogona vitticeps) in relation to benefits and predation risks in their natural habitats across southern and central Australia. Bearded dragons use elevated perches for thermoregulation and social interactions, which enhance their fitness but also increase their visibility to predators, especially raptors. We recorded perch height, lizard size, lizard sex, temperature of live dragons over multiple years. We deployed model dragons to investigate how perch height and perch type affect predation risk by raptors. We also collected dragon remains from wedge-tailed eagle (Aquila audax) nests to determine whether dragon size influences predation risk. Our findings show that larger lizards and males tend to perch higher. Predation risk from raptors increased with perch height and was greater on dead plants taller than 1 metre. Bearded dragon skulls collected from eagle nests were, on average, smaller than those from wild populations, suggesting that larger dragons may have more effective predator evasion strategies. Overall, our research highlights the complex trade-offs faced by bearded dragons between thermoregulation, social behaviours, and predation risk, deepening our understanding of their ecological dynamics and supporting conservation efforts.