Abstract. Chytridiomycosis is the worst disease to affect vertebrate biodiversity on record. In Australia, it is thought to have caused the extinction of four frog species, and it threatens the survival of at least 10 more. We report the current distribution and host range of this invasive disease in Australia, which is essential knowledge for conservation management. We envisage that the data be used in a global and national context for predictive modeling, meta-analyses, and risk assessment. Our continent-wide data set comprises 821 sites in Australia and includes 10 183 records from .80 contributors spanning collection dates from 1956 to 2007. Sick and dead frogs from the field and apparently healthy frogs from museum collections were tested opportunistically for the presence of Batrachochytrium dendrobatidis, the fungal pathogen causing chytridiomycosis, and apparently healthy frogs and tadpoles found during surveys were tested purposively. The diagnostic tests used were histology of skin samples and quantitative PCR of skin swabs.

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Cost-effective assessment tools are needed to manage the impacts of natural and human disturbances on communities. Higher taxa are widely used as surrogates for species-level identification in invertebrates; however, few studies have compared their effectiveness with species-level data for terrestrial invertebrates or assessed the mechanistic basis for their performance, and none of these studies have used a broad range of orders. Here, a terrestrial invertebrate dataset comprising 21 orders, 197 families and 751 species was used to investigate whether order-and family-level identifications were effective surrogates for species-level identification in representing patterns in assemblage structure and detecting the effects of fire. Factors potentially influencing the performance of surrogates among invertebrate orders were also investigated. Family-level identification of invertebrates in moorland sites with a wide range of fire history was found to be an effective surrogate for species-level identification. Orderlevel identification was also an effective surrogate, but the level of discrimination among sites was typically lower than for species-or family-level identification. Higher taxonomic surrogates performed well for invertebrate orders comprising a few species that were abundant and with a small mean and variance in the number of species per higher taxon. Use of higher taxa as surrogates for species-level identification can be a cost-effective approach to monitoring impacts of disturbance, but outcomes are influenced by taxonomic diversity and community structure.

Sarcoptic mange is an infectious disease impacting over 100 mammalian species around the world, including Australia’s common wombat (Vombatus ursinus). A 94% decline in a localised population attributed to mange has raised concerns for the status of the two subspecies endemic to the island state of Tasmania, Australia. We provide the first broad-scale assessment of sarcoptic mange distribution and prevalence in wombats in Tasmania. Mange-affected wombats are widespread in Tasmania from sea level to 960 m above sea level, although there are no confirmed cases from the western region of Tasmania or Maria Island. It has been recorded in most major vegetation groups, but particularly in agricultural areas. Mange prevalence estimated from night-time spotlight observation and camera surveys varied between regions (0.0–17.6%) with an overall prevalence of 4.4% for observation surveys and 0.6% for camera surveys. Time of day, survey method, and distance from observer can influence mange assessments. Local reductions in wombat numbers and animal welfare impacts due to sarcoptic mange are concerning and warrant on-going monitoring of wombats and mange, and the development and trials of effective disease management options.

Animal distribution is strongly controlled by climate, especially at higher altitudes where harsher conditions favour fewer vertebrate species. A predicted consequence of climate change is increased pressure on these higher-altitude faunal communities by invasion of lower-altitude species more suited to warmer conditions. The distribution of two such species, the broad-toothed rat (Mastacomys fuscus) and swamp rat (Rattus lutreolus) (with the former generally occurring at higher altitude except in Tasmania), were examined using BIOCLIM. Modelled climate change with a 20% reduction in precipitation and a warming of 2.9°C at latitude 36°S (Snowy Mountains) and 3.4°C at 42°S (central Tasmania) suggests that M. fuscus will retreat to higher altitudes. The core areas of R. lutreolus will also contract, but significantly they will also move so that they overlap current core areas of M. fuscus on the mainland. Barrington Tops is the northernmost known location for M. fuscus and is climatically marginal. The recent invasion of Barrington Tops by R. lutreolus and decline of M. fuscus raises the question as to whether the modelled broader range changes will result in greater competition between the invading R. lutreolus and the cool-climate specialist M. fuscus, resulting in the further loss of the latter.

Insects are the most ubiquitous and diverse group of eukaryotic organisms on Earth,

Some pathogens sustain transmission in multiple different host species, but how this epidemiologically important feat is achieved remains enigmatic. Sarcoptes scabiei is among the most host generalist and successful of mammalian parasites. We synthesize pathogen and host traits that mediate sustained transmission and present cases illustrating three transmission mechanisms (direct, indirect, and combined). The pathogen traits that explain the success of S. scabiei include immune response modulation, on-host movement capacity, off-host seeking behaviors, and environmental persistence. Sociality and host density appear to be key for hosts in which direct transmission dominates, whereas in solitary hosts, the use of shared environments is important for indirect transmission. In social den-using species, combined direct and indirect transmission appears likely. Empirical research rarely considers the mechanisms enabling S. scabiei to become endemic in host species—more often focusing on outbreaks. Our review may illuminate parasites’ adaptation strategies to sustain transmission through varied mechanisms across host species.

The COVID-19 pandemic provides a rare opportunity to reveal the impact of reduced human activity on wildlife. I compared traffic volume and wildlife roadkill data along 18 km of highway before, during and after a 3-month period of COVID-19 restrictions with baseline data from the previous four years. Three marsupial herbivores comprised 89% of the 1820 roadkills recorded during the 4.5-year survey period: rufous-bellied pademelon Thylogale billardierii (31.5% of total), common brushtail possum Trichosurus vulpecula (29.8%) and red-necked wallaby Notamacropus rufogriseus (27.9%). During April 2020, when human activity was most restricted in the study area, traffic volume decreased by 36% (i.e. by an average 13,520 vehicle movements per day) and wildlife roadkill decreased by 48% (i.e. from 44 to 23 roadkills). However, when restrictions eased, traffic volume and wildlife roadkill returned to baseline levels indicating that the respite was brief in terms of animal welfare and of limited conservation value for these widespread and abundant species. Nevertheless, the results of this study suggest that even short periods of traffic reduction or road closures could be used as part of a management strategy for the conservation of endangered wildlife populations and re-wildling programs where roadkill is a risk factor.