Non-invasive monitoring and reintroduction biology of the brush-tailed rock-wallaby (

Thirty-nine endangered brush-tailed rock-wallabies (Petrogale penicillata) were reintroduced to Grampians National Park, western Victoria, between 2008 and 2012. Subsequent high mortality, low breeding, and no recruitment were linked to fox predation and physical disturbance during monitoring. From 2014 to 2017, the colony was left undisturbed and monitored only by remote camera. Five adult animals were identified across this period (1 ♂ and 3 ♀s – all tagged; and one untagged female), and an average of 0.7 pouch young were birthed per tagged female per year. In 2019, camera-monitoring and non-invasive genetic monitoring (faecal) were used to identify colony members, genetic diversity, and breeding. Camera monitoring in 2019 identified the same five individuals, whereas genetic monitoring using 12 microsatellites identified eight individuals (two male and six female genotypes). Genetic diversity within the colony was moderate (expected heterozygosity (He) = 0.655, observed heterozygosity (Ho) = 0.854). Leaving the colony undisturbed after 2013 correlated with improved adult survival, increased breeding, and successful recruitment of young to the population. Recommendations for the Grampians colony include continuation of regular camera- and scat monitoring to improve our understanding of the reintroduction biology of P. penicillata and other marsupials in open, unfenced landscapes.

Predictively modelling the distribution of the threatened brush-tailed rock-wallaby (

Abstract Context Species Distribution Models (SDM) can be used to investigate and understand relationships between species occurrence and environmental variables, so as to predict potential distribution. These predictions can facilitate conservation actions and management decisions. Oxley Wild Rivers National Park (OWRNP) is regarded as an important stronghold for the threatened brush-tailed rock-wallaby (Petrogale penicillata), on the basis of the presence of the largest known metapopulation of the species. Adequate knowledge of the species’ ecology and distribution in OWRNP is a key objective in the national recovery plan for the species occurring in the Park. Aims To model distribution using key GIS-derived environmental factors for the brush-tailed rock-wallaby in OWRNP and to ground-truth its presence through field surveys in areas of high habitat suitability. Methods We used Maxent to model the distribution of the brush-tailed rock-wallaby within OWRNP on the basis of 282 occurrence records collected from an online database, elicitation of informal records from experts, helicopter surveys and historic records. Environmental variables used in the analysis were aspect, distance to water, elevation, geology type, slope and vegetation type. Key results Vegetation type (37.9%) was the highest contributing predictor of suitable habitat, whereas aspect (4.8%) contributed the least. The model produced an area under the curve (AUC) of the receiver operating characteristic (ROC) of 0.780. The model was able to discriminate between suitable and non-suitable habitat for brush-tailed rock-wallabies. Areas identified in our model as being highly suitable yielded eight new occurrence records during subsequent ground-truthing field surveys. Conclusions Brush-tailed rock-wallaby distribution in OWRNP is primarily associated with vegetation type, followed by distance to water, elevation, geology, slope and aspect. Field surveys indicated that the model was able to identify areas of high habitat suitability. Implications This model represents the first predicted distribution of brush-tailed rock-wallaby in OWRNP. By identifying areas of high habitat suitability, it can be used to survey and monitor the species in OWRNP, and, thus, contribute to its management and conservation within the Park.

Population persistence, breeding seasonality and sexual dimorphism in the red-necked wallaby

The red-necked wallaby (Notamacropus rufogriseus) has a broad geographic range along the eastern seaboard of Australia, but ecological research on the mainland subspecies has been limited. We aimed to assess long-term monitoring (1974 to 2017) of abundance at a site in the Grampians National Park in Victoria. Our second aim was to evaluate trap success, sexual dimorphism, breeding seasonality, longevity and home range size from intensive studies (between 2008 and 2017) at this site. The abundance of red-necked wallabies increased over time, showing no negative effect of the arrival of the swamp wallaby (Wallabia bicolor) in the 1970s. Red-necked wallabies were highly trappable: 64% of individuals were retrapped at least once, one was retrapped 38 times, and trap success did not vary seasonally. Red-necked wallabies showed high site-fidelity, with no instances of long-range movements and no sex bias in likelihood of remaining on site. One female was regularly resighted for almost eight years after her initial capture and one male lived to an estimated age of 20 years. All births occurred in the first half of the year, with a marked peak of births in February, and over three-quarters of births occurred in February and March. Red-necked wallabies were highly sexually dimorphic: the largest male (24.5kg) was nearly 10kg heavier than the largest female (15kg), and male home ranges were over five times larger than those of females.

Roughing it: terrain is crucial in identifying novel translocation sites for the vulnerable brush-tailed rock-wallaby (Petrogale pencillata)

Translocations-the movement of species from one place to another-are likely to become more common as conservation attempts to protect small isolated populations from threats posed by extreme events such as bushfires. The recent Australian mega-fires burnt almost 40% of the habitat of the brush-tailed rock-wallaby (Petrogale pencillata), a threatened species whose distribution is already restricted, primarily due to predation by invasive species. This chronic threat of over-predation, coupled with the possible extinction of the genetically distinct southern population (approx. 40 individuals in the wild), makes this species a candidate for a conservation translocation. Here, we use species distribution models to identify translocation sites for the brush-tailed rock-wallaby. Our models exhibited high predictive accuracy, and show that terrain roughness, a surrogate for predator refugia, is the most important variable. Tasmania, which currently has no rock-wallabies, showed high suitability and is fox-free, making it a promising candidate site. We outline our argument for the trial translocation of rock-wallaby to Maria Island, located off Tasmania's eastern coast. This research offers a transparent assessment of the translocation potential of a threatened species, which can be adapted to other taxa and systems.

A global review of animal translocation programs

We performed a bibliometric analysis to investigate the efficiency of release techniques (soft and hard–release), to analyse the characteristics and outcomes of the translocation programs, to identify knowledge gaps, and to provide recommendations. Animal conservation studies involving animal release to the wild increased significantly over the 31 years studied and were more frequently performed with terrestrial mammals than with other taxonomic groups. Most of the studies were performed by researchers from developed countries. Translocations occurred mostly in temperate regions, with almost no translocations occurring in the tropics. Almost 60 % of the studies did not provide information regarding the success or failure of the translocation programs. The most commonly used technique was hard release. Wild–caught specimens were preferred for translocations. Translocation programs were less common for groups like amphibians, fishes, and invertebrates. If criteria for suitable translocation are met, this management tool should also be conducted for tropical threatened species, led by native researchers. Furthermore, criteria for successful translocation should be clearly identified in order to improve future conservation actions.

Habitat influence on activity patterns of brush-tailed rock-wallabies in Queensland

The brush-tailed rock-wallaby (Petrogale penicillata) is a nocturnal refuge dependent herbivore that can be found from south-east Queensland to East Gippsland in Victoria. Brush-tailed rock-wallaby colonies are situated in many different habitat types, and refuge within this habitat is important for their survival. Dingoes coexist with P. penicillata and are perceived to be a threat. This study aimed to determine the link between habitat and P. penicillata behaviour and their interaction with predators. Three P. penicillata colonies were studied within the Little Liverpool Range, Queensland. Images of P. penicillata and dingoes from camera traps were analysed for daily activity patterns and activity overlap between species. Dingo scats were collected and analysed to determine predation. The results indicated that different habitat types change the perceived predation risk and corresponding activity patterns of P. penicillata. Predation risk impacted foraging behaviour, with rock-wallabies in exposed habitat types exhibiting greater predator avoidance behaviours than those in more protected habitat types. The results indicate that brush-tailed rock-wallabies modified their activity patterns according to different habitat types to reduce their risk of predation.