Biology subjects

Newsome, T. M.

Publications and source records attributed to Newsome, T. M..

4 recordsLinked to original sources

bioRxiv2026

'Who Goes There?' Quantifying Scavenger-Carcass Activity at Mass Mortality Events

1.Mass mortality events (MMEs) create sudden pulses of carrion that can alter how vertebrate scavengers use carcass resources, including the frequency, duration, and timing of species-carcass contacts. These changes could have implications for pathogen transmission at the scavenger-carcass interface. We aimed to develop and apply a reproducible analytical framework for using camera-trap data to quantify transmission-relevant vertebrate activity at carcass sites under differing carrion biomass scenarios. We studied experimental carcass plots (single carcass [~]43 kg; mass mortality plots [10 carcasses, >350 kg total]; 6 of each) in Australias alpine ecosystem. The framework integrated descriptive summaries (bipartite network analysis, Kaplan-Meier curves) and marked temporal point-process models to characterise structural and temporal dimensions of species-carcass activity. Mass mortality plots had greater overall visitation duration, occurring as sustained activity (50% of visitation event volume by day 17), compared with intense then rapidly declining activity at single carcasses (50% by day 8). Mass mortality plots also had higher predicted daily arrival probability and contact hours across most species, indicating an extended window for pathogen transmission. This framework provides empirically derived contact parameters for MME-related disease spread models using camera-trap data to identify potential transmission pathways at the scavenger-carcass interface.

ecology↗

bioRxiv2026

Domestic dog introgression in Australian dingoes: environmental drivers and evolutionary consequences

Introgressive hybridization between wild and domestic animals is a widespread phenomenon with important implications for genetic diversity, local adaptation, and conservation management. The causes and consequences of this process are poorly understood. In Australia, hybridization between dingoes and domestic dogs presents a dual conservation challenge, threatening the genetic integrity of dingoes while allowing potential adaptive introgression. To investigate the environmental drivers of this process, we analyzed high-density SNP array data in 390 dingoes and 396 domestic dogs. Dingo populations showed regional genetic structure and were clearly differentiated from domestic dogs. Using local ancestry inference and genome-environment association analyses, we found low levels of dog introgression in dingoes from remote areas in Central and Western Australia, and moderate levels in Eastern and Southern populations. Climatic variables (maximum temperature of the warmest month, mean temperature of the driest quarter) and the Human Footprint Index (reflecting density of human populations and environmental modifications) were significant predictors of introgression. We identified four genomic regions with overrepresented dog ancestry, including a large introgressed block on chromosome 27, which contained an olfactory receptor gene showing signatures of positive selection, suggesting adaptive introgression. In addition, a chromosomal inversion previously described in dogs and absent in dingoes was initially identified as an introgressed block. We also detected eight genomic regions nearly free of dog ancestry, suggesting purifying selection against maladaptive variants. Together, these results highlight the complex interplay between introgression, human influence, and local adaptation in dingoes, offering valuable insights for conserving the evolutionary potential of this apex predator in increasingly modified landscapes.

evolutionary biology↗

bioRxiv2024

Detection of exotic biosecurity threat ribgrass mosaic virus and novel tobamoviruses through metatranscriptomic sequencing of animal gut content

Ribgrass mosaic virus (RMV) and related viruses of the genus Tobamovirus (Virgaviridae) are cruciferous plant pathogens that represent a threat to global horticultural systems. In Australia, they are considered exotic biosecurity threats, and an incursion of these viruses would require rapid and strict control efforts. However, current surveillance methods for these viruses are limited. We examined whether RMV and related tobamoviruses could be detected by deep sequencing of gut metatranscriptomes of vertebrate animals and ticks. Using this method, we discovered that RMV, as well as a novel relative of RMV, and two highly diverse novel tobamoviruses are present in Australia. RMV was detected in multiple sites in both the Australian Capital Territory (ACT) and Tasmania, two regions separated by approximately 700km of land and 200km of water. The novel relative of RMV was detected in the ACT and New South Wales (NSW), while the highly divergent novel tobamoviruses were each detected in a single state, NSW and Queensland (QLD). In addition, Tobacco mild green mosaic virus, which is already known to be present in Australia, was detected in QLD using this method. This work highlights the potential utility of metatranscriptomic sequencing of wild animal gut for the surveillance of biosecurity threats to native and agricultural plant species. ImportancePlant viruses can have devastating impacts on global horticulture. Tobamoviruses (family Virgaviridae, genus Tobamovirus) are among the most damaging seed-borne viruses in horticultural crops, and Australia is free of many of the tobamoviruses that cause major crop losses in other countries. These viruses are extremely difficult to eradicate. Consequently, early detection of incursions is key to the control of these viruses in Australia, alongside rapid deployment of eradication and management plans. Current biosecurity surveillance methods in Australia rely on visual inspection, immunological assays, and molecular methods such as screening of imported seed lots. This study introduces a complementary approach that utilises unbiased metatranscriptomic sequencing of animal gut material to detect cryptic plant viruses circulating in nature. Using this approach, we detected five different tobamovirus circulating in Australia, including a virus thought to be exotic and three novel viruses. This unique approach highlights alternative options for surveillance/detection of exotic crop viruses.

microbiology↗

bioRxiv2020

Red fox viromes across an urban-rural gradient

The Red fox (Vulpes vulpes) has established large populations in Australias urban and rural areas since its introduction following European settlement. Foxes cryptic and highly adaptable nature allows them to invade cities and live among humans while remaining largely unnoticed. Urban living and access to anthropogenic food resources also influences fox ecology. Urban foxes grow larger, live at higher densities and are more social than their rural counterparts. These ecological changes in urban red foxes are likely to impact the pathogens that they harbour, and foxes could pose a disease risk to humans and other species that share these urban spaces. To assess this possibility, we used a meta-transcriptomic approach to characterise the viromes of urban and rural foxes across the Greater Sydney region in Australia. Urban and rural foxes differed significantly in virome composition, with rural foxes harbouring a greater abundance of viruses compared to their urban counterparts. In contrast, urban fox viromes comprised a greater diversity of viruses compared to rural foxes. We identified nine potentially novel vertebrate-associated viruses in both urban and rural foxes, some of which are related to viruses associated with disease in domestic species and humans. These included members of the Astroviridae, Picobirnaviridae, Hepeviridae and Picornaviridae as well as rabbit haemorrhagic disease virus-2 (RHDV2). This study sheds light on the viruses carried by urban and rural foxes and emphasises the need for greater genomic surveillance of foxes and other invasive species at the human-wildlife interface. ImportanceUrbanisation of wild environments is increasing as human populations continue to expand. Remnant pockets of natural environments and other green spaces in urban landscapes provide invasive wildlife such as red foxes with refuges within urban areas, where they thrive on the food resources provisioned by humans. Close contact between humans, domestic species and foxes likely increases the risk of novel pathogen emergence. Indeed, the vast majority of emerging infectious diseases in humans originate in wild animals. Here, we explored potential differences in viromes between urban fox invaders and their rural counterparts. Viromes of foxes and their ectoparasites comprise a diversity of viruses including those from the Astroviridae, Picobirnaviridae, Hepeviridae, Caliciviridae and Picornaviridae. Microbial surveillance in foxes and other urban wildlife is vital for monitoring viral emergence and for the prevention of infectious diseases.

microbiology↗