Sexual size dimorphism is widespread in mammals, often reflecting the influence of sexual selection and/or varied ecological pressures. In this study, we investigated the patterns and extent of sexual dimorphism in craniodental traits among adult dasyurid marsupials, with a primary focus on species in the subfamily Dasyurinae. This group spans a wide range of body sizes and ecological niches. Our research aimed to determine whether allometric scaling of cranial measurements differed between sexes and to assess the relationship between dimorphic traits and body size. We also explored whether sexual size dimorphism was associated with shape difference that might indicate complex functional adaptations. We analysed craniodental data to evaluate the predictive value of specific measurements for sex determination using a comparative approach across multiple dasyurid species. Our findings revealed that while sexual dimorphism was prevalent, particularly for larger species, it was not strictly correlated with body size. Shape dimorphism suggested the involvement of diet as a selective pressure, independent of size. We found that craniodental measurements could be used to discriminate between males and females for many, although not all, species but that the discriminating traits varied considerably between species. These results further our understanding of the interactions between morphology, sexual selection, and ecological roles in dasyurids, and provide important insights for interpreting the biology of both living and extinct mammalian carnivores.
Thermal drone technology is transforming wildlife monitoring, yet applications have focused almost exclusively on endothermic species. The capacity of thermal sensors to detect ectothermic reptiles in forest canopies remains largely untested. Here, we report multiple drone-based detections of arboreal snakes across three forest systems in eastern Australia: (1) tropical rainforest in the Wet Tropics of Queensland; (2) subtropical rainforest in northern New South Wales; and (3) sclerophyll forest in the south-east forests of NSW. Across all sites, a total of 20 detections of Morelia spilota (carpet pythons) and Dendrelaphis punctulatus (green tree snakes) were recorded. Detection success was strongly influenced by environmental conditions, while canopy occlusion and behavioural traits likely biased detections towards larger-bodied individuals. This study provides the first evidence that thermal drones can effectively detect arboreal snakes in forest canopies, demonstrating substantial potential for advancing our understanding of arboreal reptile ecology in structurally complex canopy environments and expanding the range of canopy-dwelling taxa identifiable using thermal drones.
Acoustic surveys detected the Eastern Tube-nosed Bat Nyctimene robinsoni at 11 remnant and restoration sites of the former Big Scrub in north-eastern New South Wales, confirming the species’ south-eastern distributional limit and extending its known eastern limit. Bats were detected more than 25 km from core habitat in the Nightcap Range and within 4 km of the coast. Calling activity occurred year-round but was much higher in spring–summer than autumn–winter. Factors such as distance from core habitat, site area, forest age, and the presence of creeks did not appear to influence calling frequency. Instead, higher activity was associated with larger, better-connected areas of regenerated vegetation, while the lowest activity occurred at smaller, more isolated sites. The species’ presence at sites without apparent roosts demonstrated its ability to cross habitat gaps of up to 6 km over cleared land, macadamia plantations, and other unsuitable habitat. Calling frequencies suggested that roosts were established in some large remnants and older plantings closer to core habitat, while more distant sites were visited less regularly, particularly during autumn–winter. Dfferences in calling rates detected between sunrise, and sunset, and night recording sessions may reflect pre-roosting contact calling. The species was detected at all but one surveyed site, indicating significant recovery since the clearing of the Big Scrub in the early 20th century. This recovery has likely been supported by ecological restoration and revegetation efforts. We highlight the importance of habitat connectivity and suggest that continued restoration and plantings will further strengthen populations and consolidate the species’ recovery in this area.
Invasive Cane Toads Rhinella marina have fatally poisoned many Freshwater Crocodiles Crocodylus johnstoni in Australia, but impacts on the larger Saltwater Crocodile C. porosus remain unknown. We photographically document six cases of free-ranging Saltwater Crocodiles capturing and consuming Cane Toads. In five cases filmed in the lower Daintree River, North Queensland, juvenile crocodiles consumed adult female toads, and in each case the crocodile held the toad for 15–20 min prior to consuming it. Crocodiles showed no overt ill-effects of toad ingestion, and in two of these cases the same crocodile was later observed alive and healthy. In the sixth case, a subadult Saltwater Crocodile in the Mary River, Northern Territory, killed and consumed multiple toads. A survey of commercial crocodile operations revealed that although captive Saltwater Crocodiles in outdoor pens were occasionally recorded to kill Cane Toads, no cases of crocodile mortality or ill-health were seen. We conclude that (unlike the case in some populations of Freshwater Crocodiles), Saltwater Crocodiles kill and ingest Cane Toads without suffering major poisoning effects.
Before European settlement, the Western Red-tailed Cockatoo Calyptorhynchus escondidus had a distribution confined to the Pilbara, Murchison, and Gascoyne regions of Western Australia. Since then, the species has expanded its range into parts of the northern and central wheatbelt of Western Australia. This paper describes a further expansion of the species’ range into a near-coastal, central wheatbelt area, and the first known breeding record in this area, representing a 72-km expansion of the known breeding range. Possible reasons for this expansion in range are discussed.
Bibliometric analyses of zoologists’ work inform management decisions increasingly, so it is pertinent to examine biases that may shape research directions, research funding, individual careers, or departments’ futures. As an example, we examined whether Scopus searches retrieve the true corpus of research documents from eight Australian Natural History Museums (ANHMs). We complemented standard Scopus searches with Scopus’ secondary documents, retrieving data on documents unlisted in Scopus but cited by documents in Scopus. Four lines of evidence indicate that much museum research is invisible in Scopus searches: (i) when assessing documents listed in annual reports, six museums had under half their listings in Scopus; (ii) five of eight researchers with up to 40 years’ employment in ANHMs had more records in secondary documents than in Scopus, with all authors improving their h-index when secondary documents were combined with Scopus documents; (iii) 8 of the 11 journals published by ANHMs were unlisted in Scopus while others had incomplete listings; and (iv) searches for ANHM research documents in the newly available OpenAlex catalogue retrieved approximately 17% more records. Prudence is needed in interpreting bibliometric evaluations, not just in museums, but for all zoologists.
Vehicle-strike accounts for the death of millions of animals annually and can cause damage to property and humans. Mitigating the potential for vehicle-strike is expensive. Therefore, objectively identifying and prioritising areas for mitigation works is important. We partitioned roads in Lismore, New South Wales into 1-km segments and overlaid this with generationally-partitioned vehicle-strike records for the threatened Koala Phascolarctos cinereus. Extending generational timeframes to accommodate under-reporting in areas of low observer density, a K-distance plot was used to identify road segments with the greatest vehicle-strike potential, whereafter we used the 95% confidence interval derived from averaging the Euclidean distances between the five nearest records to identify vehicle-strike clusters. Output was standardised into the number of koalas struck by vehicles per kilometre per generation, which we then ranked to identify road segments where the potential for ongoing vehicle-strike was greatest. We conclude that techniques of cluster analyses informed by recognised conservation criteria allow roads to be ranked by severity of impact and can therefore guide management actions that maximise financial and/or ecological return, as well as providing important baseline metrics for monitoring purposes.
Animals are motivated to search for highly desirable foods, and these motivations can be exploited to detect cryptic species. Using food-based lures with camera traps is common practice to improve detection of many species, but the effectiveness of lures may be influenced by many factors, including the availability of other food. Here, we describe evidence of stark seasonal differences in the effectiveness of a food-based lure for detecting a relatively common arboreal omnivore, the Sugar Glider Petaurus breviceps. As part of a broader research project, we tested the use of a honey-water lure during winter and spring at the same urban and peri-urban sites in northern Sydney. Sugar Gliders appeared highly motivated to visit the honey-water in winter. Sites were visited quickly, repeatedly and for longer than the very few visits to a subset of the same sites in spring. Our results reveal a stark difference in the seasonal attractiveness of a food lure to Sugar Gliders within fragmented urban bushland landscapes. These results provide evidence that results from surveys that rely on specific lures may need to be interpreted with caution during times when alternate food resources may be abundant, as negative results may indicate absence of foraging motivation for that food type rather than actual absences. Further research into seasonal shifts in food availability and nutritional requirements of arboreal omnivores may reveal further insight into the seasonal foraging ecology of specific species to better inform the use of lures for detecting cryptic species.
Monotreme fossils of pre-Pliocene Cenozoic age are very rare in Australia and limited to those of the toothed platypus Obdurodon (Ornithorhynchidae). From the late Oligocene fluvio-lacustrine sediments of central Australia, the record includes only three teeth, a partial dentary and a partial ilium, all assigned to Obdurodon insignis Woodburne and Tedford, 1975. Here, we report three more fossils attributed to O. insignis: a lower first molar; an upper second premolar; and a partial scapulocoracoid from the Namba Formation exposed at Billeroo Creek, Frome Downs Station, South Australia, which contribute to the Pinpa Local Fauna that is of late Oligocene age. The scapulocoracoid is only the second postcranial element referred to a species of Obdurodon. It shows this fossil platypus had a very similar pectoral girdle to the modern Platypus Ornithorhynchus anatinus (Shaw, 1799), which along with the general skull morphology of another ancient platypus, Obdurodon dicksoni Archer et al., 1992, suggests that the general form of the extant Platypus has existed since at least the late Oligocene.
Short-Beaked Echidnas (Tachyglossus aculeatus) are Australia’s most widespread native mammal and are found in all terrestrial environments on mainland Australia and most major islands, as well as New Guinea. Despite the obvious differences in appearance of echidnas from different areas of Australia, and their current division into five subspecies based on these differences, two mtDNA based phylogenetic studies failed to find any genetic support for the subspecies. Differences between the subspecies extend beyond variations in the hair and spines and include physical features such as the length and angle of the beak, physiological features such as use of hibernation and torpor, lactation duration and milk composition, and differences in mating behaviour and maternal care. Most of these differences appear to be directly or indirectly related to climate. Based on the fossil history and current theories of the origins of tachyglossids, the failure to find mtDNA support for the subspecies is likely to be the result of fairly recent, probably Pleistocene dispersal, consistent with immigration from New Guinea and rapid adaptation of populations to local environmental conditions. The case for recognising distinct subspecies of Tachyglossus aculeatus appears overwhelming, and some of the differences are so important I urge against making generalised statements about echidna biology if they are based on observations of one subspecies. The genetic studies do show some significant problems with the current subspecies designations: Western Australian, and probably central Australian, echidnas are not acanthion, and the dark Queensland form described as lawesii is probably not lawesii.
This paper reports and interprets a state-wide community survey of Platypus Ornithorhynchus anatinus conducted across New South Wales (NSW) in 2006, and summarises an earlier state-wide survey in 1987. The 1987 survey found that the overall distribution of the Platypus had remained stable since the early to mid-20th century, and likely since European colonisation. These two surveys remain the only broad-scale, state-wide assessments of Platypus distribution in NSW. Both relied on targeted questionnaires completed by government field personnel in 1987 and local residents in 2006. A comparison of the two surveys assessed potential changes in Platypus distribution. The 2006 survey recorded more locations than the 1987 survey, reflecting its broader reach, but when the two surveys were compared, there was no evidence of a detectable change in Platypus distribution between them. The Platypus is currently not listed as a threatened species under either NSW or Commonwealth legislation. This is a precarious position for what is arguably the world’s most evolutionarily distinct mammal. As an iconic species, the Platypus underscores the importance of conserving and managing all native wildlife, not just those already recognised as threatened.
I report an incidental mortality event involving 10 bats found within a wall-mounted mail holder in the Northern Jarrah Forest, Western Australia. The purpose of this note is to document the event and highlight the potential hazard posed by this type of structure. Eight individuals were deceased, including seven male Southern Forest Bats Vespadelus regulus and one male Chocolate Wattled Bat Chalinolobus morio, while two bats were alive and released. This observation illustrates a simple and likely under-reported anthropogenic trapping hazard associated with smooth-sided artificial structures. Documenting such incidents may assist in identifying and mitigating small-scale but preventable sources of bat mortality.
Central Queensland (CQ) is characterised by low-density koala populations, primarily inhabiting large cattle properties. This study seeks to better understand various stakeholders’ (mainly landholders) experiences and perspectives on koalas across CQ in order to identify population trends and conservation needs. The research is based on substantial qualitative interview data, which is corroborated with available historical and scientific literature to present a narrative-style social analysis. This ‘hybrid’ research approach revealed a unique picture of relationships between people and koalas in CQ. Semi-structured interviews were conducted with 88 stakeholders (landholders, community members and conservation officers) across CQ. An analysis of the interview data revealed emergent topics that provide insight into the conservation efforts and challenges related to koala management in the region. The research finds a complex but hopeful picture for CQ koalas: koalas persist across much of Central Queensland; some populations are recovering while others remain vulnerable or locally extinct; landholders care deeply about koalas but fear regulatory consequences if government knows they have koalas existing on their property. Additionally, local knowledge provides critical insight for conservation, and conservation success will depend on collaboration, trust–building, and context–specific management. This research offers a nuanced understanding of the complex relationships between koalas, land use, and local communities. It informs effective conservation strategies and gives hope for this iconic species’ survival in this region through stakeholder collaboration.
The Shingleback Lizard Tiliqua rugosa is a common and well-known skink species throughout much of Australia. Here we describe a novel interaction between a Shingleback Lizard and an agamid (dragon) lizard captured on a motion-triggered camera in Goobang National Park, NSW. The Shingleback is captured carrying the agamid lizard in its mouth, probably demonstrating either predation – not previously reported on agamid lizards – or interspecific competition. Camera traps are a widely used tool for surveying and monitoring wild animals; however, the species captured in this observation were not the target of this camera survey; this highlights the value of motion-triggered cameras for providing unique insights into the behaviour and ecology of both target and non-target species.
The Black Summer bushfires of 2019–2020 that burnt half of Kangaroo Island, South Australia, raised concerns about the status of the rare Little Pygmy-Possum Cercartetus lepidus. A bushfire recovery nest box program revealed that only the Western Pygmy-Possum Cercartetus concinnus (9.2–10.2 g) occupied boxes with 20-mm entrances (902 cavities monitored on 13 properties) and preferred them (72.4% of observations at a Dudley West property) to those with 16-mm entrances (27.6%). This more common species may have outcompeted C. lepidus (8.4–9.0 g); therefore, we tested different nest box entrance sizes in an effort to exclude C. concinnus. A 1-mm difference in the entrance diameter of boxes may favour C. lepidus over C. concinnus. Boxes that accommodate C. concinnus may benefit this species to the detriment of C. lepidus. Very small differences in box entrance size could have implications for conservation, ecological research, genetic selection, and animal welfare.
The global decline of hollow-bearing trees threatens hollow-dependent fauna and highlights the need for effective artificial refuges in habitat restoration. Nest boxes are widely used but often exhibit poor thermal performance, limited durability, and narrow species suitability. Carved hollows in living trees are an emerging alternative that may better replicate natural cavities, although their ecological performance and implementation remain poorly understood. This case study evaluated carved hollows using a purpose-designed tool (HollowHog) within a long-running nest box program in urban bushland remnants in Sydney, Australia. The study assessed ecological outcomes and implementation challenges, with implications for land managers and future research. Monitoring included 535 nest boxes and 53 carved hollows. Occupancy, attrition, and internal temperature were recorded, with observations of factors affecting hollow persistence. Nest boxes recorded 21% native vertebrate use, and 12% of carved hollows were occupied by target species. Carved hollow availability declined due to termite occupation (n = 19), water ingress (n = 5), and native bee occupation (n = 3), collectively rendering 51% hollows unusable for target fauna. Many cavities were also created smaller than design specifications, further reducing suitability. Carved hollows exhibited lower and more stable daytime temperatures than nest boxes. Despite some identified challenges, carved hollows have potential as durable and thermally stable artificial refuges if these challenges are addressed. Successful application requires attention to cavity dimensions, entrance design, tree selection, and management of woundwood, termites, and moisture. Artificial hollows cannot replicate natural cavity diversity; therefore, protecting and recruiting hollow-bearing trees remains essential for conserving hollow-dependent wildlife.
The Kimberley region in Western Australia is a hotspot for reptile species diversity. Despite this, the ecology of the region’s reptiles and relationships between predator and prey species remain poorly understood, largely due to the inaccessibility of certain areas making survey work resource-intensive. Camera traps are a cost-effective way of conducting surveys in remote areas, and during extended deployments often detect rare and cryptic species. This field note reports on the first observation of a Black-palmed Rock Monitor Varanus glebopalma predating on a Giant Slender Blue-tongue Cyclodomorphus maximus, a cryptic and rare Kimberley endemic. This observation highlights the usefulness of camera traps for detecting cryptic species and providing insight into species interactions.
The 20th International Bat Research Conference was held in August 2025 in Cairns, Queensland, at the edge of Australia’s Wet Tropics World Heritage Area. Hosted by the Australasian Bat Society and the Pacific Bat Conservation Network, the conference brought together a global community of researchers, managers and conservation practitioners to share advances in bat biology and conservation. The conference attracted 507 delegates from 58 countries in person, with a further 70 delegates online, reinforcing its role as a major international forum for chiropteran science. Four plenaries framed the program: long-term monitoring and conservation outcomes, challenges of research in resource-limited regions, the role of public engagement in shifting perceptions, and a vision for global collaboration through integrated networks. Across 16 formal symposiums, 16 themed sessions and 7 workshops, Australian research featured strongly, including advances in fruit bat ecology and management, disease ecology within a One Health framework, wind-energy interactions, and emerging tools in bioacoustics and genomics. A symposium on bat conservation research in Key Biodiversity Areas (KBA), supported by a workshop on that topic, advanced methods to identify bats as KBA trigger species and align monitoring with global standards, linking Australian and regional priorities to site-based conservation worldwide. By integrating the 10th National Flying-fox Forum, the conference created a platform for dialogue between science, policy and on-ground management concerning Australian flying-foxes. This facilitated pivotal collaborations for the conservation of federally and state-listed threatened species, while supporting the National Flying-fox Monitoring Program. Field trips across northern Queensland and overseas expeditions to the Autonomous Region of Bougainville (Papua New Guinea) and Nguna Island (Vanuatu), showcased regional bat diversity and underscored Australia’s role as a hub for Asia-Pacific capacity building. The 20th International Bat Research Conference was more than a scientific meeting: it consolidated partnerships, sharpened tools for evidence-based management, highlighted the need for long-term population monitoring, and helped advance an ambitious agenda for transboundary bat conservation in a rapidly changing world.
Climate change can be particularly devastating to species restricted to high elevations. Mount Hotham, one of Victoria’s highest peaks, contains a remarkable cohort of threatened species. The area of habitat suitable for threatened reptiles and amphibians on and near Mount Hotham is small due to topography and elevation; these habitats have been increasingly destroyed, degraded and fragmented since winter-based recreational activities commenced in the 1920s. In this century, already small and fragmented habitat patches have been further cleared, degraded, and fragmented, leaving these species in a precarious position. Despite having monitoring sites for threatened herpetofauna on and near Mount Hotham for more than 20 years, my team and I have not been consulted about proposed destruction during pre-destruction impact assessments for the species that we monitor. Similarly, our publications containing specific warnings about further harms to threatened species’ habitats in this area are often ignored in pre-destruction assessments. With patches of occupied habitat ever-shrinking due to this destruction, increasing pressure from climate change will make it very difficult and expensive to retain these species on and around Mount Hotham.
