Understanding behaviour of threatened animal species is an important component of conservation. This study assessed video and recorded data collected on a historical captive population of kultarrs (Antechinomys laniger) to describe their behaviour in captivity. The kultarr, a small marsupial in the Dasyuridae family, is native to central Australia. It is categorised as Least Concern on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species with its population assessed as decreasing. Here, we describe some key behaviours displayed by kultarrs in captivity, including grooming, nest building and use of shelter, predatory and feeding behaviour, and social behaviour. Gaining an understanding of kultarr behaviour in captivity will enhance and improve captive management of the species and provide insights into how kultarrs may behave in the wild.

Sex ratios in wild populations of mammals often differ from parity. Here, we describe variation in offspring sex ratios in a population of quenda (Isoodon fusciventer, Marsupialia: Peramelidae), along with observations of maternal body mass and home range size. We evaluate whether the Local Resource Competition (LRC) or Trivers–Willard hypothesis best explains the observed patterns in offspring sex ratio. During the study period, young (small) females over-produced sons, whereas older (larger) females tended to produce more daughters, providing evidence consistent with the LRC hypothesis in this species. There were, however, observed shifts in adult sex ratios compared to previous years. We further discuss the possibility of adaptive sex-ratio adjustment by female quenda to reduce competition with their kin.

Based on details of more than 400 platypus deaths with an identifiable cause recorded since 1989, five main factors contributed directly to platypus mortalities: drowning in fish nets or enclosed crustacean traps (such as opera house traps), being killed by predators (especially canids), becoming accidentally hooked by recreational anglers who then cut the line, becoming entangled in discarded fishing line or other types of litter and being hit by motor vehicles (especially, though not exclusively, in Tasmania). Additional mortality factors included drought, severe flooding, being drawn into irrigation pumps and entrapment in manmade materials or infrastructure. Disease was implicated as being the likely causal agent in two platypus deaths, including a female that died late in lactation. Platypus mortalities were recorded throughout the year on the southeastern Australian mainland but peaked in early autumn, when many recently weaned juveniles are likely to be present. Given the very high number of platypus mortalities attributed to the use of fish nets or enclosed crustacean traps, their use should be banned in all waters where platypus population are known to occur.

The 2019–2020 Black Summer bushfires are an example of Australia’s climate-induced, changing fire regimes, where flora and fauna suffer both direct and indirect impacts as the result of large fires. The eastern pygmy possum (Cercartetus nanus) is a species that may be affected and, although its general ecology is well understood, there is limited knowledge of its response to wildfire. Using clusters of nest boxes across two state forests on the New South Wales Central Coast, detection histories were created from 2017 to 2023. Estimates of occupancy, detection and extinction were produced, where the top ranked model included Fire severity as a covariate of extinction. Extinction probability was highest in unburnt areas, 0.55 (95% CI = 0.13–0.82) and lowest in moderate fire severity areas, 0.15 (95% CI = 0.003–0.52), although all estimates were highly uncertain. Detection probability was 0.35 per cluster visit (95% CI = 0.26–0.45) and occupancy probability was 0.77 (95% CI = 0.39–0.98), indicating a high probability of occupancy at sites affected by fire. This suggests that eastern pygmy possums may benefit from post-fire resources, such as flowering shrubs, as well as their flexible den selection, providing a niche that other arboreal animals may be unable to exploit so soon post fire.

The breeding pattern of the long-nosed potoroo (Potorous tridactylus) has not been described in the north of its geographic range. Long-nosed potoroos were continuously monitored at eight camera sites on the New England Tableland in northern New South Wales over a 17-month period. Evidence of breeding relied on detecting females with pouch bulges and young-at-foot. Breeding occurred throughout the year but pouch bulges were more commonly seen in May and October than in other months. Females produced two to four young per site, equating to 2.1 per year. This study has demonstrated the great potential of using camera trapping to describe aspects of the breeding pattern in a cryptic marsupial.

Severe flooding in early 2020 and 2021 necessitated major desedimentation works at the iconic Blue Lake in the Jenolan Karst Conservation Reserve (JKCR). Movements and behaviour of platypuses were monitored before, during and after these works, using direct observations, remote cameras and environmental DNA (eDNA) sampling. Platypuses were observed along a 3 km reach of the Jenolan River, including the areas where works occurred, although in low numbers. In their use of the available waterways, platypuses negotiated artificial barriers, including a 10 m high dam, two smaller weirs and natural waterfalls and cascades. Overland movements were detected through vegetation tunnels, drainage pipes and culverts, and individuals were seen entering the cave system, where eDNA was also detected. Platypuses responded to the works activity by foraging outside the affected areas but also continued to traverse these areas from time to time. We describe movements around and through instream infrastructure and past natural barriers and report on other species detected by remote cameras. These observations could help planning and deployment of bypasses suitable for movement of platypuses around anthropogenic barriers and provide insights into impediments to dispersal and gene flow within stream systems.

Nutrition is essential for not only survival but also successful growth and reproduction. Dietary demands are increased in a diseased state due to the increased energy and nutritional requirements associated with immune response, inflammation and convalescence. The herbivorous bare-nosed wombat (Vombatus ursinus) is notably susceptible to sarcoptic mange, a disease caused by the mite, Sarcoptes scabiei, which causes debilitating pruritic skin disease and leads to secondary bacterial infections and increased wombat morbidity and mortality, as well as regionally variable population declines. It is unknown why wombats are so susceptible to sarcoptic mange and if nutrition may play a role in disease expression, particularly relating to seasonality. The objective of this study was to quantify the differences in the nutritive value, over four seasons, of plants (mostly grasses and sedges) that are available as food items for bare-nosed wombats. We collected plants over four seasons from five wombat habitats that were known to have wombats affected by sarcoptic mange. We found seasonal and site differences for macro and micronutrients in the plants analysed. Monitoring the diet quality of wombats in the wild is useful for managing their populations and understanding population dynamics in relation to food resource quality.

Mating by a pair of wild spotted-tailed quolls was captured in a series of still images on a motion camera at the Windsor Tableland, far north Queensland. Typical of dasyurids, the mating was prolonged (5.75 h), although shorter than that usually described for captive quolls. Surprisingly, mating commenced shortly before dawn, and continued into mid-morning in an exposed location on the rainforest floor. The mating resulted in a distinctive, cleared circular area on the forest floor, similar to that described in captive situations. This may be a useful, if short-lived trace, for identifying the presence of mating quolls.

Within its core highland range, Leadbeater’s possum (Gymnobelideus leadbeateri) occurs predominantly in tall montane ash forest dominated by Eucalyptus regnans, E. delegatensis and E. nitens. To improve predictive modelling of suitable habitat, we surveyed ash/non-ash ecotones and also explored the species’ recently extended eastern distribution. We detected Leadbeater’s possums at 19 sites, including six in non-ash forest dominated by E. dalrympleana, E. viminalis or E. kybeanensis. This extends its known distribution by 5.5 km and appears to delineate the north-eastern limit of its range. Our results add to previous findings indicating Leadbeater’s possums have slightly broader range limits and habitat flexibility than previously thought.

A population of white-footed dunnarts ( Sminthopsis leucopus ) occurs in the Wet Tropics bioregion of tropical north Queensland, Australia separated by about 1800 km from conspecifics in temperate New South Wales, Victoria and Tasmania. We conducted targeted surveys for S. leucopus in north-east Queensland and obtained new records, including the first reported capture of the species in Queensland in 18 years. We assessed the genetic and morphological divergence of the north Queensland population against New South Wales, Victorian and Tasmanian S. leucopus , in conjunction with distribution and habitat differences, to assess whether this isolate should be described as a distinct taxon. Sequencing of the mitochondrial Cytochrome b gene revealed genetic divergence estimates of 2.3–2.8% and 4.3–4.8% between the north Queensland population and S. l. ferruginifrons (Victoria) and S. l. leucopus (Tasmania) respectively. Based on genetic divergence, cranial morphology, differences in habitat, and geographical isolation, we describe the north Queensland population as a new subspecies of Sminthopsis leucopus . We suggest a conservation classification of Endangered given its small distribution, apparent low density, tropical upland location and potential threats, especially related to climate change.