ORCID Profile
0000-0001-7558-9022
Current Organisation
University of Tasmania
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Environmental Science and Management | Wildlife and Habitat Management | Conservation and Biodiversity | Conservation And Biodiversity | Photogrammetry and remote sensing | Forestry Sciences | Genetics | Epidemiology | Wildlife And Habitat Management | Terrestrial Ecology | Environmental management | Population And Ecological Genetics | Forestry Management and Environment | Population ecology | Conservation and biodiversity | Community Ecology | Biological Adaptation
ANZSRC Socio-Economic Objective (SEO)
Control of Pests, Diseases and Exotic Species at Regional or Larger Scales | Flora, Fauna and Biodiversity at Regional or Larger Scales | Forest and Woodlands Flora, Fauna and Biodiversity | Living resources (flora and fauna) | Flora, Fauna and Biodiversity of environments not elsewhere classified | Control of Animal Pests, Diseases and Exotic Species in Forest and Woodlands Environments | Ecosystem Assessment and Management of Forest and Woodlands Environments | Living resources (flora and fauna) | Native Forests | Land and water management | Economic issues | Farmland, Arable Cropland and Permanent Cropland Flora, Fauna and Biodiversity |
Related Links
Publications
Tasman-PCR: a genetic diagnostic assay for Tasmanian devil facial tumour diseases
Publisher: The Royal Society
Date: 10-2018
DOI: 10.1098/RSOS.180870
Abstract: Tasmanian devils have spawned two transmissible cancer clones, known as devil facial tumour 1 (DFT1) and devil facial tumour 2 (DFT2). DFT1 and DFT2 are transmitted between animals by the transfer of allogeneic contagious cancer cells by biting, and both cause facial tumours. DFT1 and DFT2 tumours are grossly indistinguishable, but can be differentiated using histopathology, cytogenetics or genotyping of polymorphic markers. However, standard diagnostic methods require specialist skills and equipment and entail long processing times. Here, we describe Tasman-PCR: a simple polymerase chain reaction (PCR)-based diagnostic assay that identifies and distinguishes DFT1 and DFT2 by lification of DNA spanning tumour-specific interchromosomal translocations. We demonstrate the high sensitivity and specificity of this assay by testing DNA from 546 tumours and 804 normal devils. A temporal–spatial screen confirmed the reported geographic ranges of DFT1 and DFT2 and did not provide evidence of additional DFT clones. DFT2 affects disproportionately more males than females, and devils can be co-infected with DFT1 and DFT2. Overall, we present a PCR-based assay that delivers rapid, accurate and high-throughput diagnosis of DFT1 and DFT2. This tool provides an additional resource for devil disease management and may assist with ongoing conservation efforts.
DRIFT DISSEMINULES ON CAYS OF THE SWAIN REEFS, GREAT BARRIER-REEF, AUSTRALIA
Publisher: JSTOR
Date: 1990
DOI: 10.2307/2845183
GPS collars are more efficient when collecting high-frequency data
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/AM15034
Abstract: Selecting an appropriate fix schedule has a pivotal role when using GPS collars. On the basis of deployments of GPS collars on 35 cats, we report on an often overlooked consideration: that GPS units are more efficient collecting data at high frequencies (15 min between fixes in this study) than low frequencies ( h between fixes).
Untangling the model muddle: Empirical tumour growth in Tasmanian devil facial tumour disease
Publisher: Springer Science and Business Media LLC
Date: 24-07-2017
DOI: 10.1038/S41598-017-06166-3
Abstract: A pressing and unresolved topic in cancer research is how tumours grow in the absence of treatment. Despite advances in cancer biology, therapeutic and diagnostic technologies, there is limited knowledge regarding the fundamental growth and developmental patterns in solid tumours. In this ten year study, we estimated growth curves in Tasmanian devil facial tumours, a clonal transmissible cancer, in males and females with two different karyotypes (diploid, tetraploid) and facial locations (mucosal, dermal), using established differential equation models and model selection. Logistic growth was the most parsimonious model for diploid, tetraploid and mucosal tumours, with less model certainty for dermal tumours. Estimates of daily proportional tumour growth rate per day (95% Bayesian CIs) varied with ploidy and location [diploid 0.016 (0.014–0.020), tetraploid 0.026 (0.020–0.033), mucosal 0.013 (0.011–0.015), dermal 0.020 (0.016–0.024)]. Final tumour size (cm 3 ) also varied, particularly the upper credible interval owing to host mortality as tumours approached maximum volume [diploid 364 (136–2,475), tetraploid 172 (100–305), dermal 226 (134–471)]. To our knowledge, these are the first empirical estimates of tumour growth in the absence of treatment in a wild population. Through this animal-cancer system our findings may enhance understanding of how tumour properties interact with growth dynamics in other types of cancer.
Reference genome of the endangered eastern quoll (Dasyurus viverrinus)
Publisher: Cold Spring Harbor Laboratory
Date: 07-09-2023
Regional patterns of continuing decline of the eastern quoll
Publisher: CSIRO Publishing
Date: 20-09-2023
DOI: 10.1071/AM22010
Abstract: Like many other Australian mammals, eastern quolls (Dasyurus viverrinus) were widespread in the south-east of mainland Australia but went extinct there during the 20th century. The species remained abundant in Tasmania until it rapidly declined from 2001 to 2003, coinciding with a period of unsuitable weather. We provide an updated analysis of eastern quoll population trends in Tasmania using a time series of annual spotlight counts (1985–2019) collected across most of the species’ range. Eastern quolls were widespread and abundant in Tasmania until the early 2000s. In addition to the previously documented severe decline in the early 2000s in the east and northeast, we present new evidence of an earlier decline in the north (mid-1990s) and a more recent decline in the south (~2009). Declines have continued unabated during the last decade, resulting in a ~67% decline since the late 1990s in the area with high quoll abundance. Although the major decline in the early 2000s coincided with unfavourable weather, the continuing and more recent declines suggest other undetermined causes are also involved. We can no longer assume the presence of eastern quolls in Tasmania ensures the species’ long-term survival, highlighting the urgent need to conserve the remaining populations in Tasmania.
Home range size scales to habitat amount and increasing fragmentation in a mobile woodland specialist
Publisher: Wiley
Date: 18-11-2019
DOI: 10.1002/ECE3.5837
Rapid evolutionary response to a transmissible cancer in Tasmanian devils
Publisher: Springer Science and Business Media LLC
Date: 30-08-2016
DOI: 10.1038/NCOMMS12684
Abstract: Although cancer rarely acts as an infectious disease, a recently emerged transmissible cancer in Tasmanian devils ( Sarcophilus harrisii ) is virtually 100% fatal. Devil facial tumour disease (DFTD) has swept across nearly the entire species’ range, resulting in localized declines exceeding 90% and an overall species decline of more than 80% in less than 20 years. Despite epidemiological models that predict extinction, populations in long-diseased sites persist. Here we report rare genomic evidence of a rapid, parallel evolutionary response to strong selection imposed by a wildlife disease. We identify two genomic regions that contain genes related to immune function or cancer risk in humans that exhibit concordant signatures of selection across three populations. DFTD spreads between hosts by suppressing and evading the immune system, and our results suggest that hosts are evolving immune-modulated resistance that could aid in species persistence in the face of this devastating disease.
Spatial variation in gene expression of Tasmanian devil facial tumors despite minimal host transcriptomic response to infection
Publisher: Springer Science and Business Media LLC
Date: 27-09-2021
DOI: 10.1186/S12864-021-07994-4
Abstract: Transmissible cancers lie at the intersection of oncology and infectious disease, two traditionally ergent fields for which gene expression studies are particularly useful for identifying the molecular basis of phenotypic variation. In oncology, transcriptomics studies, which characterize the expression of thousands of genes, have identified processes leading to heterogeneity in cancer phenotypes and in idual prognoses. More generally, transcriptomics studies of infectious diseases characterize interactions between host, pathogen, and environment to better predict population-level outcomes. Tasmanian devils have been impacted dramatically by a transmissible cancer (devil facial tumor disease DFTD) that has led to widespread population declines. Despite initial predictions of extinction, populations have persisted at low levels, due in part to heterogeneity in host responses, particularly between sexes. However, the processes underlying this variation remain unknown. We sequenced transcriptomes from healthy and DFTD-infected devils, as well as DFTD tumors, to characterize host responses to DFTD infection, identify differing host-tumor molecular interactions between sexes, and investigate the extent to which tumor gene expression varies among host populations. We found minimal variation in gene expression of devil lip tissues, either with respect to DFTD infection status or sex. However, 4088 genes were differentially expressed in tumors among our s ling localities. Pathways that were up- or downregulated in DFTD tumors relative to normal tissues exhibited the same patterns of expression with greater intensity in tumors from localities that experienced DFTD for longer. No mRNA sequence variants were associated with expression variation. Expression variation among localities may reflect morphological differences in tumors that alter ratios of normal-to-tumor cells within biopsies. Phenotypic variation in tumors may arise from environmental variation or differences in host immune response that were undetectable in lip biopsies, potentially reflecting variation in host-tumor coevolutionary relationships among sites that differ in the time since DFTD arrival.
Boldness towards novelty and translocation success in captive-raised, orphaned Tasmanian devils
Publisher: Wiley
Date: 28-12-2013
DOI: 10.1002/ZOO.21108
Abstract: Translocation of endangered animals is common, but success is often variable and/or poor. Despite its intuitive appeal, little is known with regards to how in idual differences amongst translocated animals influence their post-release survival, growth, and reproduction. We measured consistent pre-release responses to novelty in a familiar environment (boldness repeatability=0.55) and cortisol response in a group of captive-reared Tasmanian devils, currently listed as "Endangered" by the IUCN. The devils were then released at either a hard- or soft-release site within their mothers' population of origin, and in idual growth, movement, reproduction (females only), and survival across 2-8 months post-release was measured. Sex, release method, cohort, behavior, and cortisol response did not affect post-release growth, nor did these factors influence the home range size of orphan devils. Final linear distances moved from the release site were impacted heavily by the release cohort, but translocated devils' movement overall was not different from that in the same-age wild devils. All orphan females of reproductive age were subsequently captured with offspring. Overall survival rates in translocated devils were moderate (∼42%), and were not affected by devil sex, release method, cohort, release weight, or pre-release cortisol response. Devils that survived during the study period were, however, 3.5 times more bold than those that did not (effect size r=0.76). Our results suggest that conservation managers may need to provide developmental conditions in captivity that promote a wide range of behaviors across in iduals slated for wild release.
Fresh meteoric versus recirculated saline groundwater nutrient inputs into a subtropical estuary
Publisher: Elsevier BV
Date: 10-2016
Calcium mobilization, water balance, and growth in embryos of the agamid lizard Amphibolurus barbatus
Publisher: Wiley
Date: 09-2018
Abstract: Embryos of the agamid lizard Amphibolurus barbatus are at developmental stage 29 of Dufaure and Hubert at the time of oviposition. Mobilization of calcium and other nutrients from the yolk proceeds slowly for the first half of incubation, during which time embryonic growth also proceeds slowly. During the second half of incubation, however, embryos withdraw calcium and other nutrients from the yolk very rapidly, and growth rates are correspondingly high. Approximately 60% of the calcium used by developing embryos is obtained from the yolk, but fully 40% of their requirement is met by calcium mobilized from the eggshell. Very little calcium remains in residual yolk of hatchlings, so this yolk must be used in maintenance metabolism rather than in growth of neonates. No dichotomy exists among oviparous, amniotic vertebrates with respect to sources of calcium used by developing embryos, but one does exist with respect to patterns of mobilization of this element. Whereas calcium is extracted from yolk of embryonic reptiles throughout incubation, it actually is deposited in yolk of embryonic birds after the midpoint in development.
Demonstration of immune responses against devil facial tumour disease in wild Tasmanian devils
Publisher: The Royal Society
Date: 10-2016
Abstract: Devil facial tumour disease (DFTD) is a recently emerged fatal transmissible cancer decimating the wild population of Tasmanian devils ( Sarcophilus harrisii ). Biting transmits the cancer cells and the tumour develops in the new host as an allograft. The literature reports that immune escape mechanisms employed by DFTD inevitably result in host death. Here we present the first evidence that DFTD regression can occur and that wild devils can mount an immune response against the disease. Of the 52 devils tested, six had serum antibodies against DFTD cells and, in one case, prominent T lymphocyte infiltration in its tumour. Notably, four of the six devils with serum antibody had histories of DFTD regression. The novel demonstration of an immune response against DFTD in wild Tasmanian devils suggests that a proportion of wild devils can produce a protective immune response against naturally acquired DFTD. This has implications for tumour–host coevolution and vaccine development.
The genomic basis of tumor regression in Tasmanian devils (Sarcophilus harrisii)
Publisher: Oxford University Press (OUP)
Date: 13-10-2018
DOI: 10.1093/GBE/EVY229
Distribution and impacts of Tasmanian devil facial tumor disease
Publisher: Springer Science and Business Media LLC
Date: 11-09-2007
Ancient
DNA
tracks the mainland extinction and island survival of the Tasmanian devil
Publisher: Wiley
Date: 04-2018
DOI: 10.1111/JBI.13214
Hope and caution: Rewilding to mitigate the impacts of biological invasions
Publisher: The Royal Society
Date: 22-10-2018
Abstract: Rewilding is a novel approach to ecological restoration. Trophic rewilding in particular aims to reinstate ecological functions, especially trophic interactions, through the introduction of animals. We consider the potential for trophic rewilding to address biological invasions. In this broad review, we note some of the important conceptual and ethical foundations of rewilding, including a focus on ecosystem function rather than composition, reliance on animal agency, and an appeal to an ethic of coexistence. Second, we use theory from invasion biology to highlight pathways by which rewilding might prevent or mitigate the impacts of an invasion, including increasing biotic resistance. Third, we use a series of case studies to illustrate how reintroductions can mitigate the impacts of invasions. These include reintroductions and positive management of carnivores and herbivores including European pine martens ( Martes martes ), Eurasian otters ( Lutra lutra ), dingoes ( Canis dingo ), Tasmanian devils ( Sarcophilus harrisii ) and tule elk ( Cervus canadensis nannodes ). Fourth, we consider the risk that rewilding may enable a biological invasion or aggravate its impacts. Lastly, we highlight lessons that rewilding science might take from invasion biology. This article is part of the theme issue ‘Trophic rewilding: consequences for ecosystems under global change’.
New insights into the role of MHC diversity in devil facial tumour disease
Publisher: Public Library of Science (PLoS)
Date: 06-06-2012
Extracellular vesicle proteomes of two transmissible cancers of Tasmanian devils reveal tenascin-C as a serum-based differential diagnostic biomarker
Publisher: Springer Science and Business Media LLC
Date: 16-10-2021
DOI: 10.1007/S00018-021-03955-Y
Abstract: The iconic Tasmanian devil (Sarcophilus harrisii) is endangered due to the transmissible cancer Devil Facial Tumour Disease (DFTD), of which there are two genetically independent subtypes (DFT1 and DFT2). While DFT1 and DFT2 can be differentially diagnosed using tumour biopsies, there is an urgent need to develop less-invasive biomarkers that can detect DFTD and distinguish between subtypes. Extracellular vesicles (EVs), the nano-sized membrane-enclosed vesicles present in most biofluids, represent a valuable resource for biomarker discovery. Here, we characterized the proteome of EVs from cultured DFTD cells using data-independent acquisition-mass spectrometry and an in-house spectral library of > 1500 proteins. EVs from both DFT1 and DFT2 cell lines expressed higher levels of proteins associated with focal adhesion functions. Furthermore, hallmark proteins of epithelial-mesenchymal transition were enriched in DFT2 EVs relative to DFT1 EVs. These findings were validated in EVs derived from serum s les, revealing that the mesenchymal marker tenascin-C was also enriched in EVs derived from the serum of devils infected with DFT2 relative to those infected with DFT1 and healthy controls. This first EV-based investigation of DFTD increases our understanding of the cancers' EVs and their possible involvement in DFTD progression, such as metastasis. Finally, we demonstrated the potential of EVs to differentiate between DFT1 and DFT2, highlighting their potential use as less-invasive liquid biopsies for the Tasmanian devil.
Unlocking environmental accounting for healthy future landscapes
Publisher: Wiley
Date: 09-2022
DOI: 10.1002/PAN3.10378
Abstract: Competing land‐use demands for agriculture and nature conservation is one of the most significant global challenges. To improve the health of landscapes, collaborative transdisciplinary solutions are required. Environmental accounting is an attractive governance approach for helping to deliver healthy future landscapes however, the ersity of approaches to environmental accounting makes this field complex to navigate, which limits transdisciplinary collaboration and impedes implementation. We seek to address this issue by presenting a new framework to clarify environmental accounting. This framework classifies the currently disparate branches of the literature into four newly described environmental accounting types: Organisational Environmental Management Accounting, Organisational Environmental Reporting Accounting, Area Environmental Management Accounting and Area Environmental Reporting Accounting. The framework is then used to discuss, across multiple scales (organisational, ecosystem and national), existing environmental accounting tools which could assist in delivering healthy future landscapes, and areas for future research. Finally, we demonstrate the potential for environmental accounting research approaches (materiality assessment, dialogic accounting and critical accounting) to assist in defining healthy future landscapes. This paper presents the first substantial exploration of environmental accounting in the landscapes context and presents a research agenda to progress this exciting area of transdisciplinary research. Read the free Plain Language Summary for this article on the Journal blog.
An exotic woody weed in a pastoral landscape provides habitat for many native species, but has no apparent threatened species conservation significance
Publisher: Wiley
Date: 31-08-2018
DOI: 10.1111/EMR.12338
Uranium export from a sandy beach subterranean estuary in Australia
Publisher: Elsevier BV
Date: 11-2017
Over-eruption in marsupial carnivore teeth: compensation for a constraint
Publisher: Cold Spring Harbor Laboratory
Date: 18-03-2023
DOI: 10.1101/2023.03.16.533044
Abstract: Pronounced over-eruption of the canine teeth, much greater than in eco-morphologically equivalent placental carnivores, occurs with age and growth in Australian marsupial carnivores. Suppression of functional tooth replacement is a characteristic of marsupials and is frequent among erse placentals, where the primitive therian pattern is two generations of incisor, canine and premolar teeth. Rapid determinate growth is one among multiple hypotheses proposed to explain the loss of tooth replacement in mammals. In this line of reasoning, the animal reaches a sufficient body or jaw size to accommodate adult-sized teeth by the time it requires functional dentition. Marsupial carnivores have a full set of adult anterior teeth at weaning, which erupt into a juvenile jaw that is 25 to 30 % adult size, compared with well grown in placental carnivores. Indeterminate over-eruption of the canine teeth in marsupial carnivores results in increasing canine height and diameter with increasing body size with age, suggesting this is a compensatory mechanism for the constraint of a single generation of anterior teeth. Patterns of over-eruption in different tooth types of marsupial carnivores are consistent with two non-exclusive mechanisms that operate in other mammals, a response to tooth wear and lack of an occlusal partner.
Sperm competition drives the evolution of suicidal reproduction in mammals
Publisher: Proceedings of the National Academy of Sciences
Date: 07-10-2013
Abstract: In some marsupial genera but in no other mammals, escalating stress hormones during the breeding season cause immune system collapse and synchronized death after mating in all males (suicidal reproduction). In this paper, we resolve the environmental drivers and adaptive mechanism of sexual selection responsible for the repeated evolution of this surprising and extreme life history strategy in mammals. The strategy of synchronized suicidal reproduction in mammals resulting in male death before offspring are born has often been attributed to altruistic or kin-selected paternal suicide to avoid food depletion. We show that rather than altruism or kin-selection, in idual sexual selection leads to apparent self-sacrifice in these genera.
Conservation management of Tasmanian devils in the context of an emerging, extinction-threatening disease: Devil Facial Tumor Disease
Publisher: Springer Science and Business Media LLC
Date: 06-09-2007
The evolution of two transmissible cancers in Tasmanian devils
Publisher: Cold Spring Harbor Laboratory
Date: 27-05-2022
DOI: 10.1101/2022.05.27.493404
Abstract: Tasmanian devils have spawned two transmissible cancer lineages, named devil facial tumour 1 (DFT1) and devil facial tumour 2 (DFT2). We investigated the genetic ersity and evolution of these clones by analysing 78 DFT1 and 41 DFT2 genomes relative to a newly assembled chromosome-level reference. Time-resolved phylogenetic trees reveal that DFT1 first emerged in 1986 (1982-1989), and DFT2 in 2011 (2009-2012). Subclone analysis documents transmission of heterogeneous cell populations. DFT2 has faster mutation rates than DFT1 across all variant classes, including substitutions, indels, rearrangements, transposable element insertions and copy number alterations, and we identify a hypermutated DFT1 lineage with defective DNA mismatch repair. Several loci show plausible evidence of positive selection in DFT1 or DFT2, including loss of chromosome Y and inactivation of MGA , but none are common to both cancers. This study illuminates the parallel long-term evolution of two transmissible cancers inhabiting a common niche in Tasmanian devils.
The devil's cancer
Publisher: Springer Science and Business Media LLC
Date: 06-2011
To lose both would look like carelessness: Tasmanian Devil Facial Tumour Disease
Publisher: Public Library of Science (PLoS)
Date: 17-10-2006
Biting injuries and transmission of Tasmanian devil facial tumour disease
Publisher: Wiley
Date: 03-09-2013
DOI: 10.1111/J.1365-2656.2012.02025.X
Abstract: The Tasmanian devil is threatened with extinction by devil facial tumour disease (DFTD), a unique infectious cancer in which the tumour cells themselves, which derive from a single long-dead host devil, are the infective agent and the tumour is an infectious parasitic cell line. Transmission is thought to occur via direct inoculation of tumour cells when susceptible and infected in iduals bite each other or by fomitic transfer of tumour cells. The nature of transmission and the extent to which biting behaviour and devil ecology is associated with infection risk remains unclear. Until our recent study in north-west Tasmania showed reduced population and in idual impacts, DFTD had caused massive population declines in all populations monitored. In this paper, we investigate seasonal patterns of injuries resulting from bites between in iduals, DFTD infection status and tumour location in two populations to determine whether the number of bites predicts the acquisition of DFTD and to explore the possibility that the reduced impacts of DFTD in north-west Tasmania are attributed to reduced bite rates. Devils with fewer bites were more likely to develop DFTD and primary tumours occurred predominantly inside the oral cavity. These results are not consistent with transmission occurring from the biter to the bitten animal but suggest that dominant in iduals delivering bites, possibly by biting the tumours of other devils, are at higher risk of acquiring infection than submissive in iduals receiving bites. Bite rates, which were higher during autumn and winter, did not differ between sites, suggesting that the reduced population impacts in north-west Tasmania cannot be explained by lower bite rates. Our study emphasizes the importance of longitudinal studies of in idually marked animals for understanding the ecology and transmission dynamics of infectious diseases and parasites in wild populations.
Protecting islands from pest invasion: Response to Greenslade et al.
Publisher: Elsevier BV
Date: 2013
Tracing the rise of malignant cell lines: Distribution, epidemiology and evolutionary interactions of two transmissible cancers in Tasmanian devils
Publisher: Wiley
Date: 28-06-2019
DOI: 10.1111/EVA.12831
Groundwater discharge into an estuary using spatially distributed radon time series and radium isotopes
Publisher: Elsevier BV
Date: 09-2015
Reintroduction of Tasmanian devils to mainland Australia can restore top-down control in ecosystems where dingoes have been extirpated: A response to Baker et al. 2016 and Fancourt & Mooney 2016
Publisher: Elsevier BV
Date: 04-2016
Testing the role of climate change in species decline: Is the eastern quoll a victim of a change in the weather?
Publisher: Public Library of Science (PLoS)
Date: 24-06-2015
Sex bias in ability to cope with cancer: Tasmanian devils and facial tumour disease
Publisher: The Royal Society
Date: 21-11-2018
Abstract: Knowledge of the ecological dynamics between hosts and pathogens during the initial stages of disease emergence is crucial to understanding the potential for evolution of new interspecific interactions. Tasmanian devil ( Sarcophilus harrisii ) populations have declined precipitously owing to infection by a transmissible cancer (devil facial tumour disease, DFTD) that emerged approximately 20 years ago. Since the emergence of DFTD, and as the disease spreads across Tasmania, the number of devils has dropped up to 90% across 80% of the species's distributional range. As a result, the disease is expected to act as a strong selective force on hosts to develop mechanisms of tolerance and/or resistance to the infection. We assessed the ability of infected devils to cope with infection, which translates into host tolerance to the cancer, by using the reaction norm of the in idual body condition by tumour burden. We found that body condition of infected hosts is negatively affected by cancer progression. Males and females presented significant differences in their tolerance levels to infection, with males suffering declines of up to 25% of their body condition, in contrast to less than 5% in females. Sex-related differences in tolerance to cancer progression may select for changes in life-history strategies of the host and could also alter the selective environment for the tumours.
Simulating devil facial tumour disease outbreaks across empirically derived contact networks
Publisher: Wiley
Date: 23-01-2012
Life-history change in disease-ravaged Tasmanian devil populations
Publisher: Proceedings of the National Academy of Sciences
Date: 22-07-2008
Abstract: Changes in life history are expected when new sources of extrinsic mortality impact on natural populations. We report a new disease, devil facial tumor disease, causing an abrupt transition from iteroparity toward single breeding in the largest extant carnivorous marsupial, the Tasmanian devil ( Sarcophilus harrisii ), in which males can weigh as much as 14 kg and females 9 kg. This change in life history is associated with almost complete mortality of in iduals from this infectious cancer past their first year of adult life. Devils have shown their capacity to respond to this disease-induced increased adult mortality with a 16-fold increase in the proportion of in iduals exhibiting precocious sexual maturity. These patterns are documented in five populations where there are data from before and after disease arrival and subsequent population impacts. To our knowledge, this is the first known case of infectious disease leading to increased early reproduction in a mammal. The persistence of both this disease and the associated life-history changes pose questions about longer-term evolutionary responses and conservation prospects for this iconic species.
Sins of omission and sins of commission: St Thomas Aquinas and the devil
Publisher: Royal Zoological Society of New South Wales
Date: 2010
DOI: 10.7882/AZ.2010.019
Host, environment, and anthropogenic factors drive landscape dynamics of an environmentally transmitted pathogen: Sarcoptic mange in the bare‐nosed wombat
Publisher: Wiley
Date: 23-05-2023
Abstract: Understanding the spatial dynamics and drivers of wildlife pathogens is constrained by s ling logistics, with implications for advancing the field of landscape epidemiology and targeted allocation of management resources. However, visually apparent wildlife diseases, when combined with remote‐surveillance and distribution modelling technologies, present an opportunity to overcome this landscape‐scale problem. Here, we investigated dynamics and drivers of landscape‐scale wildlife disease, using clinical signs of sarcoptic mange (caused by Sarcoptes scabiei ) in its bare‐nosed wombat (BNW Vombatus ursinus ) host. We used 53,089 camera‐trap observations from over 3261 locations across the 68,401 km 2 area of Tasmania, Australia, combined with landscape data and ensemble species distribution modelling (SDM). We investigated: (1) landscape variables predicted to drive habitat suitability of the host (2) host and landscape variables associated with clinical signs of disease in the host and (3) predicted locations and environmental conditions at greatest risk of disease occurrence, including some Bass Strait islands where BNW translocations are proposed. We showed that the Tasmanian landscape, and ecosystems therein, are nearly ubiquitously suited to BNWs. Only high mean annual precipitation reduced habitat suitability for the host. In contrast, clinical signs of sarcoptic mange disease in BNWs were widespread, but heterogeneously distributed across the landscape. Mange (which is environmentally transmitted in BNWs) was most likely to be observed in areas of increased host habitat suitability, lower annual precipitation, near sources of freshwater and where topographic roughness was minimal (e.g. human modified landscapes, such as farmland and intensive land‐use areas, shrub and grass lands). Thus, a confluence of host, environmental and anthropogenic variables appear to influence the risk of environmental transmission of S. scabiei . We identified that the Bass Strait Islands are highly suitable for BNWs and predicted a mix of high and low suitability for the pathogen. This study is the largest spatial assessment of sarcoptic mange in any host species, and advances understanding of the landscape epidemiology of environmentally transmitted S. scabiei . This research illustrates how host‐pathogen co‐suitability can be useful for allocating management resources in the landscape.
Infection of the fittest: devil facial tumour disease has greatest effect on individuals with highest reproductive output
Publisher: Wiley
Date: 10-05-2017
DOI: 10.1111/ELE.12776
Comparative landscape genetics reveals differential effects of environment on host and pathogen genetic structure in Tasmanian devils (Sarcophilus harrisii) and their transmissible tumour
Publisher: Wiley
Date: 02-08-2020
DOI: 10.1111/MEC.15558
The ecology and evolution of wildlife cancers: Applications for management and conservation
Publisher: Wiley
Date: 23-03-2020
DOI: 10.1111/EVA.12948
Abstract: Ecological and evolutionary concepts have been widely adopted to understand host–pathogen dynamics, and more recently, integrated into wildlife disease management. Cancer is a ubiquitous disease that affects most metazoan species however, the role of oncogenic phenomena in eco‐evolutionary processes and its implications for wildlife management and conservation remains undeveloped. Despite the pervasive nature of cancer across taxa, our ability to detect its occurrence, progression and prevalence in wildlife populations is constrained due to logistic and diagnostic limitations, which suggests that most cancers in the wild are unreported and understudied. Nevertheless, an increasing number of virus‐associated and directly transmissible cancers in terrestrial and aquatic environments have been detected. Furthermore, anthropogenic activities and sudden environmental changes are increasingly associated with cancer incidence in wildlife. This highlights the need to upscale surveillance efforts, collection of critical data and developing novel approaches for studying the emergence and evolution of cancers in the wild. Here, we discuss the relevance of malignant cells as important agents of selection and offer a holistic framework to understand the interplay of ecological, epidemiological and evolutionary dynamics of cancer in wildlife. We use a directly transmissible cancer (devil facial tumour disease) as a model system to reveal the potential evolutionary dynamics and broader ecological effects of cancer epidemics in wildlife. We provide further ex les of tumour–host interactions and trade‐offs that may lead to changes in life histories, and epidemiological and population dynamics. Within this framework, we explore immunological strategies at the in idual level as well as transgenerational adaptations at the population level. Then, we highlight the need to integrate multiple disciplines to undertake comparative cancer research at the human–domestic–wildlife interface and their environments. Finally, we suggest strategies for screening cancer incidence in wildlife and discuss how to integrate ecological and evolutionary concepts in the management of current and future cancer epizootics.
Rate of intersexual interactions affects injury likelihood in Tasmanian devil contact networks
Publisher: Oxford University Press (OUP)
Date: 25-04-2019
Abstract: Identifying the types of contacts that result in disease transmission is important for accurately modeling and predicting transmission dynamics and disease spread in wild populations. We investigated contacts within a population of adult Tasmanian devils (Sarcophilus harrisii) over a 6-month period and tested whether in idual-level contact patterns were correlated with accumulation of bite wounds. Bite wounds are important in the spread of devil facial tumor disease, a clonal cancer cell line transmitted through direct inoculation of tumor cells when susceptible and infected in iduals bite each other. We used multimodel inference and network autocorrelation models to investigate the effects of in idual-level contact patterns, identities of interacting partners, and position within the social network on the propensity to be involved in bite-inducing contacts. We found that males were more likely to receive potentially disease-transmitting bite wounds than females, particularly during the mating season when males spend extended periods mate-guarding females. The number of bite wounds in iduals received during the mating season was unrelated to any of the network metrics examined. Our approach illustrates the necessity for understanding which contact types spread disease in different systems to assist the management of this and other infectious wildlife diseases.
NICHE DIFFERENTIATION AMONG SYMPATRIC AUSTRALIAN DASYURID CARNIVORES
Publisher: No publisher found
Date: 2000
DOI: 10.1644/1545-1542%282000%29081%3C0434%3ANDASAD%3E2.0.CO%3B2
Amplified predation after fire suppresses rodent populations in Australia's tropical savannas
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/WR15011
Abstract: Context Changes in abundance following fire are commonly reported for vertebrate species, but the mechanisms causing these changes are rarely tested. Currently, many species of small mammals are declining in the savannas of northern Australia. These declines have been linked to intense and frequent fires in the late dry season however, why such fires cause declines of small mammals is unknown. Aims We aimed to discover the mechanisms causing decline in abundance of two species of small mammals, the pale field rat, Rattus tunneyi, and the western chestnut mouse, Pseudomys nanus, in response to fire. Candidate mechanisms were (1) direct mortality because of fire itself, (2) mortality after fire because of removal of food by fire, (3) reduced reproductive success, (4) emigration, and (5) increased mortality because of predation following fire. Methods We used live trapping to monitor populations of these two species under the following three experimental fire treatments: high-intensity fire that removed all ground vegetation, low-intensity fire that produced a patchy burn, and an unburnt control. We also radio-tracked 38 R. tunneyi in iduals to discover the fates of in idual animals. Key results Abundance of both species declined after fire, and especially following the high-intensity burn. There was no support for any of the first four mechanisms of population decline, but mortality owing to predation increased after fire. This was related to loss of ground cover (which was greater in the high-intensity fire treatment), which evidently left animals exposed to predators. Also, local activity of two predators, feral cats and dingoes, increased after the burns, and we found direct evidence of predation by feral cats and snakes. Conclusions Fire in the northern savannas has little direct effect on populations of these small mammals, but it causes declines by lifying the impacts of predators. These effects are most severe for high-intensity burns that remove a high proportion of vegetation cover. Implications To prevent further declines in northern Australia, fire should be managed in ways that limit the effects of increased predation. This could be achieved by setting cool fires that produce patchy burns, avoiding hot fires, and minimising the total area burnt.
Conservation trade-offs: island introduction of a threatened predator suppresses invasive mesopredators but eliminates a seabird colony
Publisher: Elsevier BV
Date: 08-2020
MHC gene copy number variation in Tasmanian devils: Implications for the spread of a contagious cancer
Publisher: The Royal Society
Date: 10-03-2010
Abstract: Tasmanian devils face extinction owing to the emergence of a contagious cancer. Devil facial tumour disease (DFTD) is a clonal cancer spread owing to a lack of major histocompatibility complex (MHC) barriers in Tasmanian devil populations. We present a comprehensive screen of MHC ersity in devils and identify 25 MHC types and 53 novel sequences, but conclude that overall levels of MHC ersity at the sequence level are low. The majority of MHC Class I variation can be explained by allelic copy number variation with two to seven sequence variants identified per in idual. MHC sequences are ided into two distinct groups based on sequence similarity. DFTD cells and most devils have sequences from both groups. Twenty per cent of in iduals have a restricted MHC repertoire and contain only group I or only group II sequences. Counterintuitively, we postulate that the immune system of in iduals with a restricted MHC repertoire may recognize foreign MHC antigens on the surface of the DFTD cell. The implication of these results for management of DFTD and this endangered species are discussed.
Relaxation of risk-sensitive behaviour of prey following disease-induced decline of an apex predator, the Tasmanian devil
Publisher: The Royal Society
Date: 07-07-2015
Abstract: Apex predators structure ecosystems through lethal and non-lethal interactions with prey, and their global decline is causing loss of ecological function. Behavioural changes of prey are some of the most rapid responses to predator decline and may act as an early indicator of cascading effects. The Tasmanian devil ( Sarcophilus harrisii ), an apex predator, is undergoing progressive and extensive population decline, of more than 90% in long-diseased areas, caused by a novel disease. Time since local disease outbreak correlates with devil population declines and thus predation risk. We used hair traps and giving-up densities (GUDs) in food patches to test whether a major prey species of devils, the arboreal common brushtail possum ( Trichosurus vulpecula ), is responsive to the changing risk of predation when they forage on the ground. Possums spend more time on the ground, discover food patches faster and forage more to a lower GUD with increasing years since disease outbreak and greater devil population decline. Loss of top–down effects of devils with respect to predation risk was evident at 90% devil population decline, with possum behaviour indistinguishable from a devil-free island. Alternative predators may help to maintain risk-sensitive anti-predator behaviours in possums while devil populations remain low.
A triple threat: high population density, high foraging intensity and flexible habitat preferences explain high impact of feral cats on prey
Publisher: The Royal Society
Date: 06-01-2020
Abstract: Alien mammalian carnivores have contributed disproportionately to global loss of bio ersity. In Australia, predation by the feral cat and red fox is one of the most significant causes of the decline of native vertebrates. To discover why cats have greater impacts on prey than native predators, we compared the ecology of the feral cat to a marsupial counterpart, the spotted-tailed quoll. In idual prey are 20–200 times more likely to encounter feral cats, because of the combined effects of cats' higher population densities, greater intensity of home-range use and broader habitat preferences. These characteristics also mean that the costs to the prey of adopting anti-predator behaviours against feral cats are likely to be much higher than adopting such behaviours in response to spotted-tailed quolls, due to the reliability and ubiquity of feral cat cues. These results help explain the devastating impacts of cats on wildlife in Australia and other parts of the world.
Is anti-predator behaviour in Tasmanian eastern quolls (Dasyurus viverrinus) effective against introduced predators?
Publisher: Wiley
Date: 05-2004
Making the connection: expanding the role of restoration genetics in restoring and evaluating connectivity
Publisher: Wiley
Date: 12-03-2018
DOI: 10.1111/REC.12692
Feral Cats Are Better Killers in Open Habitats, Revealed by Animal-Borne Video
Publisher: Public Library of Science (PLoS)
Date: 19-08-2015
Discovery of Biomarkers for Tasmanian Devil Cancer (DFTD) by Metabolic Profiling of Serum
Publisher: American Chemical Society (ACS)
Date: 23-09-2016
DOI: 10.1021/ACS.JPROTEOME.6B00629
Abstract: Devil facial tumor disease (DFTD) is a transmissible cancer threatening Tasmanian devils (Sarcophilus harrisii) with extinction. There is no preclinical test available for DFTD, and thus our aim was to find biomarkers for DFTD by metabolic fingerprinting. Seventy serum s les from wild Tasmanian devils (35 controls, 35 with tumors) were analyzed by liquid chromatography-high-resolution mass spectrometry. Features were selected by multivariate models (PLS/DA, random forests) comparing age-matched training set (n = 20 × 2) and further complying with fold-change threshold (≥1.4) and Mann-Whitney U-tests with correction for multiple hypotheses (false discovery rate (FDR) q 0.45, p < 0.01). Additional potential markers included amino acid and lipid metabolites, while cortisol and urea were the most significant health predictors (AUC ≥ 0.90). PLS/DA resulted in AUC = 0.997 for the training set and overall sensitivity of 91% and specificity of 97%. A support vector machine model utilizing only the major peptide marker and seven other metabolites led to overall 94% sensitivity and specificity. The novel findings in this first DFTD metabolomics study shed light on metabolic changes in Tasmanian devils affected by DFTD and provide a valuable step toward the development of prognostic biomarkers.
Active adaptive conservation of threatened species in the face of uncertainty
Publisher: Wiley
Date: 07-2010
DOI: 10.1890/09-0647.1
Abstract: Adaptive management has a long history in the natural resource management literature, but despite this, few practitioners have developed adaptive strategies to conserve threatened species. Active adaptive management provides a framework for valuing learning by measuring the degree to which it improves long-run management outcomes. The challenge of an active adaptive approach is to find the correct balance between gaining knowledge to improve management in the future and achieving the best short-term outcome based on current knowledge. We develop and analyze a framework for active adaptive management of a threatened species. Our case study concerns a novel facial tumor disease affecting the Australian threatened species Sarcophilus harrisii: the Tasmanian devil. We use stochastic dynamic programming with Bayesian updating to identify the management strategy that maximizes the Tasmanian devil population growth rate, taking into account improvements to management through learning to better understand disease latency and the relative effectiveness of three competing management options. Exactly which management action we choose each year is driven by the credibility of competing hypotheses about disease latency and by the population growth rate predicted by each hypothesis under the competing management actions. We discover that the optimal combination of management actions depends on the number of sites available and the time remaining to implement management. Our approach to active adaptive management provides a framework to identify the optimal amount of effort to invest in learning to achieve long-run conservation objectives.
Evaluation of selective culling of infected individuals to control Tasmanian devil facial tumor disease,Evaluacíon de la extraccíon selectiva de individuos infectados para controlar la enfermedad de tumor facial en el demonio de Tasmania
Publisher: Wiley
Date: 19-01-2010
DOI: 10.1111/J.1523-1739.2009.01429.X
Abstract: Sustainable strategies to manage infectious diseases in threatened wildlife are still lacking despite considerable concern over the global increase in emerging infectious diseases of wildlife and their potential to drive populations to extinction. Selective culling of infected in iduals will often be the most feasible option to control infectious disease in a threatened wildlife host, but has seldom been implemented or evaluated as a management tool for the conservation of threatened species. The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction by an infectious cancer, devil facial tumor disease (DFTD). We assess the success of an adaptive management trial involving selective culling of infected Tasmanian devils to control DFTD. Demographic and epidemiological parameters indicative of disease progression and impact were compared between the management site and a comparable unmanaged control site. Selective culling of infected in iduals neither slowed rate of disease progression nor reduced population-level impacts of this debilitating disease. Culling mortality simply compensated for disease mortality in this system. Failure of selective culling to impede DFTD progress and reduce its impacts in the managed population was attributed to DFTD's frequency-dependent nature, its long latent period and high degree of infectivity, and the presence of a cryptic hidden disease reservoir or continual immigration of diseased in iduals. We suggest that increasing the current removal rate and focusing removal efforts prior to the breeding season are options worth pursuing for future management of DFTD in this population. On the basis of our experience, we suggest that disease-management programs for threatened wildlife populations be developed on the principles of adaptive management and utilize a wide variety of strategies with regular reviews and adaptation of strategies undertaken as new information is obtained.
Macropod studies at wallaby creek. VIII. Individual recognition of kangaroos and wallabies
Publisher: CSIRO Publishing
Date: 1989
DOI: 10.1071/WR9890179
Abstract: Recognition of in idual large mammals by natural features is an ancient practice, the usefulness of which has recently become appreciated in field studies. We show that such recognition is possible and repeatable, under particular circumstances, with macropodid marsupials in the field in Australia. In trials, there was a 98% agreement between observers in identification of in iduals of both eastern grey kangaroos Macropus giganteus and red-necked wallabies M. rufogriseus. Characters used to identify in iduals were first definitive ('oddity') characters, and then specific sets of character-states. However, in time observers came to recognise in iduals 'on sight', by unconscious summation of character-states. Recognition skills could be readily learned by observers, allowing almost complete populations of these species to be known and the component members studied in idually. The technique should be applicable in studies of other macropodid populations.
Short-term pain before long-term gain? Suppression of invasive primary prey temporarily increases predation on native lizards
Publisher: Springer Science and Business Media LLC
Date: 16-03-2020
Demography, disease and the devil: Life-history changes in a disease-affected population of Tasmanian devils (Sarcophilus harrisii)
Publisher: Wiley
Date: 03-2009
DOI: 10.1111/J.1365-2656.2008.01494.X
Abstract: 1. Examining the demographic responses of populations to disease epidemics and the nature of compensatory responses to perturbation from epidemics is critical to our understanding of the processes affecting population dynamics and our ability to conserve threatened species. Such knowledge is currently available for few systems. 2. We examined changes to the demography and life-history traits of a population of Tasmanian devils (Sarcophilus harrisii) following the arrival of a debilitating infectious disease, devil facial tumour disease (DFTD), and investigated the population's ability to compensate for the severe population perturbation caused by this epizootic. 3. There was a significant change to the age structure following the arrival of DFTD to the Freycinet Peninsula. This shift to a younger population was caused by the loss of older in iduals from the population as a direct consequence of DFTD-driven declines in adult survival rates. 4. Offspring sex ratios of disease mothers were more female biased than those of healthy mothers, indicating that devils may facultatively adjust offspring sex ratios in response to disease-induced changes in maternal condition. 5. We detected evidence of reproductive compensation in response to disease impacts via a reduction in the age of sexual maturity of females (an increase in precocial breeding) over time. 6. The strength of this compensatory response appeared to be limited by factors that constrain the ability of in iduals to reach a critical size for sexual maturity in their first year, because of the time limit dictated by the annual breeding season. 7. The ongoing devastating impacts of this disease for adult survival and the apparent reliance of precocial breeding on rapid early growth provide the opportunity for evolution to favour of this new life-history pattern, highlighting the potential for novel infectious diseases to be strong selective forces on life-history evolution.
A transmissible cancer shifts from emergence to endemism in Tasmanian devils
Publisher: American Association for the Advancement of Science (AAAS)
Date: 11-12-2020
Abstract: The emergence of a devastating transmissible facial cancer among Tasmanian devils over the past few decades has caused substantial concern for their future because these animals are already threatened by a regional distribution and other stressors. Little is known about the overall history and trajectory of this disease. Patton et al. used an epidemiological phylodynamic approach to reveal the pattern of disease emergence and spread. They found that low Tasmanian devil densities appear to be contributing to slower disease growth and spread, which is good news for Tasmanian devil persistence and suggests that care should be taken when considering options for increasing devil populations. Science , this issue p. eabb9772
Development of a SNP-based assay for measuring genetic diversity in the Tasmanian devil insurance population
Publisher: Springer Science and Business Media LLC
Date: 14-10-2015
Groundwater vulnerability assessment in agricultural areas using a modified DRASTIC model
Publisher: Springer Science and Business Media LLC
Date: 09-12-2016
Extraterritorial hunting expeditions to intense fire scars by feral cats
Publisher: Springer Science and Business Media LLC
Date: 02-03-2016
DOI: 10.1038/SREP22559
Abstract: Feral cats are normally territorial in Australia’s tropical savannahs and hunt intensively with home-ranges only two to three kilometres across. Here we report that they also undertake expeditions of up to 12.5 km from their home ranges to hunt for short periods over recently burned areas. Cats are especially likely to travel to areas burned at high intensity, probably in response to vulnerability of prey soon after such fires. The movements of journeying cats are highly directed to specific destinations. We argue that the effect of this behaviour is to increase the aggregate impact of cats on vulnerable prey. This has profound implications for conservation, considering the ubiquity of feral cats and global trends of intensified fire regimes.
Portable X-ray Fluorescence for Measuring Lead in the Hair of Wild Mammals
Publisher: Cold Spring Harbor Laboratory
Date: 15-03-2023
DOI: 10.1101/2023.03.13.531209
Abstract: Lead exposure threatens scavenging wildlife globally. For inexpensive estimation of lead concentration in bones from avian scavengers, portable X-ray fluorescence (XRF) devices have been trialed. However, portable XRF has not been validated for tissue lead measurement in non-human mammalian scavengers. We evaluated portable XRF for hair lead measurement in the endangered Tasmanian devil ( Sarcophilus harrisii ). We first analyzed large (∼1.0 g) hair s les from 39 deceased animals from southeastern Tasmania via portable XRF and then inductively-coupled plasma mass spectrometry (ICP-MS) (validation study). We then measured lead concentrations via portable XRF only in 61 small (∼0.1 g) hair s les from live devils from a plantation landscape (plantation study). Portable XRF measures of hair lead levels were positively correlated with ICP-MS values ( R 2 = 0.61). In the validation study, 95% of s led Tasmanian devils had relatively low lead levels ( 2 mg/kg), but the remaining two showed elevated lead levels ( 15 mg/kg). Mean lead levels in the plantation study and validation study were not significantly different. Our preliminary results suggest that portable XRF can provide a useful measure of differences in lead levels in wildife hair over a coarse scale. We provide recommendations for further research and refinement of this method. Portable XRF can provide inexpensive and non-destructive analysis of environmental contaminants in wildlife. We present the first evaluation of portable XRF for analysis of lead contamination in mammalian scavenger hair.
Applying an animal-centric approach to improve ecological restoration
Publisher: Wiley
Date: 20-10-2016
DOI: 10.1111/REC.12447
Emerging disease and population decline of an island endemic, the Tasmanian devil Sarcophilus harrisii
Publisher: Elsevier BV
Date: 08-2006
Innovative tidal control successfully promotes saltmarsh restoration
Publisher: Wiley
Date: 06-09-2023
DOI: 10.1111/REC.13774
Abstract: The reduction of saltmarsh habitat at a global scale has seen a concomitant loss of associated ecosystem services. As such, there is a need and a push for habitat rehabilitation. This study examined an innovative saltmarsh restoration project in Australia which sought to address the threats of mangrove encroachment and sea level rise. The project was implemented in 2017, using automated hydraulic control gates, termed “SmartGates,” to lower the tidal regime over one site, effectively reversing sea level rise at a local level. Measured indicators of saltmarsh cover, number of species, seedling counts, and saltmarsh assemblages all showed significant positive development over time, with trends varying based on saltmarsh zone. The saltmarsh, predominantly Sarcocornia quinqueflora , developed from remnant supralittoral (previously high) marsh which remained at 45% cover to achieve over 15% coverage across the cleared habitat after 3 years. Slower development in the low marsh ( %) compared to other zones contrasts with other saltmarsh restoration studies which may be due to the unique nature of the restoration method or the nature of Australian saltmarsh species which favor higher elevations and drier conditions. The development of saltmarsh at the treatment site was found to track toward that at comparison sites over time, becoming similar to some comparison sites by the studies end. This study highlights the usefulness of the novel restoration method used and of the measured indicators for assessing saltmarsh development. This innovative tidal control method could play an important role in the future of saltmarsh restoration worldwide.
The impact of disease on the survival and population growth rate of the Tasmanian devil
Publisher: Wiley
Date: 09-2007
DOI: 10.1111/J.1365-2656.2007.01272.X
Abstract: 1. We investigated the impact of a recently emerged disease, Devil Facial Tumour Disease (DFTD), on the survival and population growth rate of a population of Tasmanian devils, Sarcophilus harrisii, on the Freycinet Peninsula in eastern Tasmania. 2. Cormack-Jolly-Seber and multistate mark-recapture models were employed to investigate the impact of DFTD on age- and sex-specific apparent survival and transition rates. Disease impact on population growth rate was investigated using reverse-time mark-recapture models. 3. The arrival of DFTD triggered an immediate and steady decline in apparent survival rates of adults and subadults, the rate of which was predicted well by the increase in disease prevalence in the population over time. 4. Transitions from healthy to diseased state increased with disease prevalence suggesting that the force of infection in the population is increasing and that the epidemic is not subsiding. 5. The arrival of DFTD coincided with a marked, ongoing decline in the population growth rate of the previously stable population, which to date has not been offset by population compensatory responses.
Genetic diversity and population structure of the endangered marsupial Sarcophilus harrisii (Tasmanian devil)
Publisher: Proceedings of the National Academy of Sciences
Date: 27-06-2011
Abstract: The Tasmanian devil ( Sarcophilus harrisii ) is threatened with extinction because of a contagious cancer known as Devil Facial Tumor Disease. The inability to mount an immune response and to reject these tumors might be caused by a lack of genetic ersity within a dwindling population. Here we report a whole-genome analysis of two animals originating from extreme northwest and southeast Tasmania, the maximal geographic spread, together with the genome from a tumor taken from one of them. A 3.3-Gb de novo assembly of the sequence data from two complementary next-generation sequencing platforms was used to identify 1 million polymorphic genomic positions, roughly one-quarter of the number observed between two genetically distant human genomes. Analysis of 14 complete mitochondrial genomes from current and museum specimens, as well as mitochondrial and nuclear SNP markers in 175 animals, suggests that the observed low genetic ersity in today's population preceded the Devil Facial Tumor Disease disease outbreak by at least 100 y. Using a genetically characterized breeding stock based on the genome sequence will enable preservation of the extant genetic ersity in future Tasmanian devil populations.
Groundwater seepage as a driver of CO2 evasion in a coastal lake (Lake Ainsworth, NSW, Australia)
Publisher: Springer Science and Business Media LLC
Date: 10-02-2015
Habitat amount and quality, not patch size, determine persistence of a woodland-dependent mammal in an agricultural landscape
Publisher: Springer Science and Business Media LLC
Date: 05-10-2018
Biologically meaningful scents: a framework for understanding predator–prey research across disciplines
Publisher: Wiley
Date: 26-04-2017
DOI: 10.1111/BRV.12334
Abstract: Fear of predation is a universal motivator. Because predators hunt using stealth and surprise, there is a widespread ability among prey to assess risk from chemical information - scents - in their environment. Consequently, scents often act as particularly strong modulators of memory and emotions. Recent advances in ecological research and analytical technology are leading to novel ways to use this chemical information to create effective attractants, repellents and anti-anxiolytic compounds for wildlife managers, conservation biologists and health practitioners. However, there is extensive variation in the design, results, and interpretation of studies of olfactory-based risk discrimination. To understand the highly variable literature in this area, we adopt a multi-disciplinary approach and synthesize the latest findings from neurobiology, chemical ecology, and ethology to propose a contemporary framework that accounts for such disparate factors as the time-limited stability of chemicals, highly canalized mechanisms that influence prey responses, and the context within which these scents are detected (e.g. availability of alternative resources, perceived shelter, and ambient physical parameters). This framework helps to account for the wide range of reported responses by prey to predator scents, and explains, paradoxically, how the same in idual predator scent can be interpreted as either safe or dangerous to a prey animal depending on how, when and where the cue was deposited. We provide a hypothetical ex le to illustrate the most common factors that influence how a predator scent (from dingoes, Canis dingo) may both attract and repel the same target organism (kangaroos, Macropus spp.). This framework identifies the catalysts that enable dynamic scents, odours or odorants to be used as attractants as well as deterrents. Because effective scent tools often relate to traumatic memories (fear and/or anxiety) that cause future avoidance, this information may also guide the development of appeasement, enrichment and anti-anxiolytic compounds, and help explain the observed variation in post-traumatic-related behaviours (including post-traumatic stress disorder, PTSD) among erse terrestrial taxa, including humans.
Road upgrade, road mortality and remedial measures: Impacts on a population of eastern quolls and Tasmanian devils
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/WR98069
Abstract: The impact of road mortality on local populations of wildlife has rarely been quantified. In June 1991, the access road into the northern end of the Cradle Mountain – Lake St Clair National Park in Tasmania was widened and sealed. This occurred part-way through an ecological study of the dasyurid carnivore guild, during which populations were being monitored. In 17 months, the resident population of 19 eastern quolls became extinct and the devil population, of 39 in iduals, halved. Concurrently, there was a dramatic increase in the number of road-kills. The main causal factor was probably an increase in modal speed of about 20 km h–1 and a greater increase in maximum speed. Measures were implemented to reduce the incidence of vehicle/wildlife collisions. Measures directed at people included physically slowing traffic speed (using ‘slow points’) and increasing driver awareness (signs and p hlets). Those directed at wildlife included deterring wildlife from crossing the road in the path of approaching vehicles (wildlife reflectors), and encouraging escape off the road (r s across gutters and banks, and pipes for shelter). The ‘slow points’ were effective in reducing vehicle speeds by 20 km h–1. Wildlife used the r s and pipes. The eastern quoll population was re-establishing within six months, and after two years, had recovered to 50% of its former level. There was some indication that devil populations were recovering.
Beyond spatial overlap: harnessing new technologies to resolve the complexities of predator–prey interactions
Publisher: Wiley
Date: 21-02-2022
DOI: 10.1111/OIK.09004
Abstract: Predation risk, the probability that a prey animal will be killed by a predator, is fundamental to theoretical and applied ecology. Predation risk varies with animal behavior and environmental conditions, yet attempts to understand predation risk in natural systems often ignore important ecological and environmental complexities, relying instead on proxies for actual risk such as predator–prey spatial overlap. Here we detail the ecological and environmental complexities driving disconnects between three stages of the predation sequence that are often assumed to be tightly linked: spatial overlap, encounters and prey capture. Our review highlights several major sources of variability in natural predator–prey systems that lead to the decoupling of spatial overlap estimates from actual encounter rates (e.g. temporal activity patterns, predator and prey movement capacity, resource limitations) and that affect the probability of prey capture given encounter (e.g. predator hunger levels, temporal, topographic and other environmental influences on capture success). Emerging technologies and statistical methods are facilitating a transition to a more spatiotemporally detailed, mechanistic understanding of predator–prey interactions, allowing for the concurrent examination of multiple stages of the predation sequence in mobile, free‐ranging animals. We describe crucial applications of this new understanding to fundamental and applied ecology, highlighting opportunities to better integrate ecological contingencies into dynamic predator–prey models and to harness a mechanistic understanding of predator–prey interactions to improve targeting and effectiveness of conservation interventions.
Density and home range of feral cats in north-western Australia
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/WR14180
Abstract: Context Feral cats (Felis catus) pose a significant threat to bio ersity in Australia, and are implicated in current declines of small mammals in the savannas of northern Australia. Basic information on population density and ranging behaviour is essential to understand and manage threats from feral cats. Aims In this study, we provide robust estimates of density and home range of feral cats in the central Kimberley region of north-western Australia, and we test whether population density is affected by livestock grazing, small mammal abundance and other environmental factors. Methods Densities were measured at six transects s led between 2011 and 2013 using arrays of infrared cameras. Cats were in idually identified, and densities estimated using spatially explicit capture–recapture analysis. Home range was measured from GPS tracking of 32 cats. Key results Densities were similar across all transects and deployments, with a mean of 0.18 cats km–2 (range = 0.09–0.34 km–2). We found no evidence that population density was related to livestock grazing or abundance of small mammals. Home ranges of males were, on average, 855 ha (±156 ha (95% CI), n = 25), and those of females were half the size at 397 ha (±275 ha (95% CI), n = 7). There was little overlap in ranges of cats of the same sex. Conclusions Compared with elsewhere in Australia outside of semiarid regions, feral cats occur at low density and have large home ranges in the central Kimberley. However, other evidence shows that despite this low density, cats are contributing to declines of small mammal populations across northern Australia. Implications It will be very difficult to reduce these already-sparse populations by direct control. Instead, land-management practices that reduce the impacts of cats on prey should be investigated.
Conserving adaptive potential: lessons from Tasmanian devils and their transmissible cancer
Publisher: Springer Science and Business Media LLC
Date: 02-2019
Genetic diversity and population structure of Tasmanian devils, the largest marsupial carnivore
Publisher: Wiley
Date: 09-07-2004
Cathelicidin-3 associated with serum extracellular vesicles enables early diagnosis of a transmissible cancer
Publisher: Cold Spring Harbor Laboratory
Date: 07-12-2021
DOI: 10.1101/2021.12.06.471373
Abstract: The identification of practical early diagnosis biomarkers is a cornerstone of improved prevention and treatment of cancers. Such a case is devil facial tumour disease (DFTD), a highly lethal transmissible cancer afflicting virtually an entire species, the Tasmanian devil ( Sarcophilus harrisii ). Despite a latent period that can exceed one year, to date DFTD diagnosis requires visual identification of tumour lesions. To enable earlier diagnosis, which is essential for the implementation of effective conservation strategies, we analysed the extracellular vesicle (EV) proteome of 87 Tasmanian devil serum s les. The antimicrobial peptide cathelicidin-3 (CATH3) was enriched in serum EVs of both devils with clinical DFTD (87.9% sensitivity and 94.1% specificity) and devils with latent infection (i.e., collected while overtly healthy, but 3-6 months before subsequent DFTD diagnosis 93.8% sensitivity and 94.1% specificity). As antimicrobial peptides can play a variety of roles in the cancer process, our results suggest that the specific elevation of serum EV-associated CATH3 may be mechanistically involved in DFTD pathogenesis. This EV-based approach to biomarker discovery is directly applicable to improving understanding and diagnosis of a broad range of diseases in other species, and these findings directly enhance the capacity of conservation strategies to ensure the viability of the imperilled Tasmanian devil population.
Beyond the disease: Is Toxoplasma gondii infection causing population declines in the eastern quoll (Dasyurus viverrinus)?
Publisher: Elsevier BV
Date: 08-2014
Characteristics of mammal communities in Tasmanian forests: exploring the influence of forest type and disturbance history
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/WR10025
Abstract: Context With increasing pressure worldwide on forest habitat, it is crucial to understand faunal ecology to effectively manage and minimise impacts of anthropogenic habitat disturbance. Aims This study assessed whether differences in forest type and disturbance history were reflected in small to medium mammal communities found in Tasmania’s production forests. Methods Trapping was conducted in spring and summer, and autumn and winter during 2007–08 at four dry Eucalyptus forest sites (two regenerating after harvest and two in relatively undisturbed forest) in south-east Tasmania, and four wet Eucalyptus forest sites (two regenerating after harvest and two in relatively undisturbed forest) in north-east Tasmania. All sites were embedded within a matrix of mature or older aged regenerating forest. Key results Thirteen mammal species were recorded across all sites. There was no difference in species ersity or richness between forest type or disturbance regime, but species composition differed. Total number of in idual animals and captures was influenced strongly by forest type and disturbance history, with most animals captured in the dry disturbed forest sites. Abundance of some species (e.g. bettongs and potoroos) was higher in disturbed sites than undisturbed sites. Brushtail possum numbers (adults and offspring), however, were lower in disturbed sites and populations displayed a male biased adult sex ratio and lower breeding frequency. Habitat structural complexity and vegetation ersity within core sites, and age structure of the forest in the surrounding landscape did not vary significantly, indicating that broad resource (food and refuge) availability was equivalent across sites. Conclusions In general, the small to medium mammals in this study did not appear to be significantly affected by forest harvesting in the medium term. Implications Although past harvesting altered the abundance of some habitat features (e.g. canopy cover, basal area of trees, and tree hollow availability), we suggest that the availability of such features in the surrounding landscape may mitigate the potential effects of disturbance on the species for which such habitat features are important.
Greenhouse gases and submarine groundwater discharge in a Sydney Harbour embayment (Australia)
Publisher: Elsevier BV
Date: 07-2018
Top predator restricts the niche breadth of prey: effects of assisted colonization of Tasmanian devils on a widespread omnivorous prey
Publisher: The Royal Society
Date: 15-03-2023
Abstract: Few landscape-scale experiments test the effects of predators on the abundance and distribution of prey across habitat gradients. We use the assisted colonization of a top predator, the Tasmanian devil ( Sarcophilus harrisii ), to test the impacts of predation on the abundance, habitat use and temporal activity of a widespread prey species, the omnivorous common brushtail possum ( Trichosurus vulpecula ). Before introduction of devils to Maria Island, Tasmania, Australia, in 2012, possums were abundant in open grasslands as well as forests. Predation by devils caused high mortality of possums in grasslands, but in iduals with access to trees had a higher survival probability. Possum abundance declined across the whole island from 2012–2016, as possums disappeared almost completely from grasslands and declined in drier forests with more open understorey. Abundance remained stable in wet forests, which are not preferred habitat for possums but provide better refuge from devils. Abundance and habitat use of possums remained unchanged at a control site on the adjacent Tasmanian mainland, where the devil population was low and stable. This study demonstrates how spatial variation in predator-caused mortality can limit both abundance and habitat breadth in generalist prey species, excluding them entirely from certain habitats.
Hematologic and serum biochemical changes associated with Devil Facial Tumor Disease in Tasmanian Devils
Publisher: Wiley
Date: 09-2016
DOI: 10.1111/VCP.12391
Abstract: Devil Facial Tumor Disease (DFTD) is an infectious tumor causing significant population declines in wild Tasmanian Devils. While clinical assessment and pathology have been well reported for DFTD, there is a lack of information on hematologic and biochemical alterations associated with DFTD. The purpose of the study was to determine hematologic and serum biochemical variation in healthy, wounded, and DFTD-affected Tasmanian Devils. Blood s les were collected from wild Tasmanian Devils at 5 sites in Tasmania. Hematology and clinical biochemistry variables were compared between clinically healthy, wounded, and DFTD-affected devils. Differences were also analyzed among stages of DFTD, including in iduals pre- and postclinical signs developing, and between ulcerated and nonulcerated DFTD tumors. Statistically significantly increased counts in WBC, neutrophils, and platelets, and concentration of fibrinogen, as well as decreased counts in lymphocytes, erythrocytes, and HGB concentration were observed in DFTD-affected devils compared to healthy devils. Activities of ALP, ALT, and GLDH, concentrations of sodium, potassium and albumin, and sodium-to-potassium ratio and albumin-to-globulin ratio were significantly lower, and AST activity was significantly higher in animals with DFTD when compared to clinically healthy animals. No significant differences were found among stages of DFTD or ulcerated and nonulcerated tumors. The differences in hematology and clinical chemistry variables in devils with DFTD compared to healthy devils are nonspecific and reflective of acute phase response and inflammation, and anemia of chronic disease. Similar changes are observed with wounds but to a lesser extent.
Influence of genetic provenance and birth origin on productivity of the Tasmanian devil insurance population
Publisher: Springer Science and Business Media LLC
Date: 10-07-2015
Individual and temporal variation in pathogen load predicts long-term impacts of an emerging infectious disease
Publisher: Wiley
Date: 15-02-2019
DOI: 10.1002/ECY.2613
Anthropogenic selection enhances cancer evolution in Tasmanian devil tumours
Publisher: Wiley
Date: 06-11-2014
DOI: 10.1111/EVA.12117
Antigen-presenting genes and genomic copy number variations in the Tasmanian devil MHC
Publisher: Springer Science and Business Media LLC
Date: 12-03-2012
Abstract: The Tasmanian devil ( Sarcophilus harrisii ) is currently under threat of extinction due to an unusual fatal contagious cancer called Devil Facial Tumour Disease (DFTD). DFTD is caused by a clonal tumour cell line that is transmitted between unrelated in iduals as an allograft without triggering immune rejection due to low levels of Major Histocompatibility Complex (MHC) ersity in Tasmanian devils. Here we report the characterization of the genomic regions encompassing MHC Class I and Class II genes in the Tasmanian devil. Four genomic regions approximately 960 kb in length were assembled and annotated using BAC contigs and physically mapped to devil Chromosome 4q. 34 genes and pseudogenes were identified, including five Class I and four Class II loci. Interestingly, when two haplotypes from two in iduals were compared, three genomic copy number variants with sizes ranging from 1.6 to 17 kb were observed within the classical Class I gene region. One deletion is particularly important as it turns a Class Ia gene into a pseudogene in one of the haplotypes. This deletion explains the previously observed variation in the Class I allelic number between in iduals. The frequency of this deletion is highest in the northwestern devil population and lowest in southeastern areas. The third sequenced marsupial MHC provides insights into the evolution of this dynamic genomic region among the erse marsupial species. The two sequenced devil MHC haplotypes revealed three copy number variations that are likely to significantly affect immune response and suggest that future work should focus on the role of copy number variations in disease susceptibility in this species.
The tumour is in the detail: Local phylogenetic, population and epidemiological dynamics of a transmissible cancer in Tasmanian devils
Publisher: Wiley
Date: 20-06-2023
DOI: 10.1111/EVA.13569
Abstract: Infectious diseases are a major threat for bio ersity conservation and can exert strong influence on wildlife population dynamics. Understanding the mechanisms driving infection rates and epidemic outcomes requires empirical data on the evolutionary trajectory of pathogens and host selective processes. Phylodynamics is a robust framework to understand the interaction of pathogen evolutionary processes with epidemiological dynamics, providing a powerful tool to evaluate disease control strategies. Tasmanian devils have been threatened by a fatal transmissible cancer, devil facial tumour disease (DFTD), for more than two decades. Here we employ a phylodynamic approach using tumour mitochondrial genomes to assess the role of tumour genetic ersity in epidemiological and population dynamics in a devil population subject to 12 years of intensive monitoring, since the beginning of the epidemic outbreak. DFTD molecular clock estimates of disease introduction mirrored observed estimates in the field, and DFTD genetic ersity was positively correlated with estimates of devil population size. However, prevalence and force of infection were the lowest when devil population size and tumour genetic ersity was the highest. This could be due to either differential virulence or transmissibility in tumour lineages or the development of host defence strategies against infection. Our results support the view that evolutionary processes and epidemiological trade‐offs can drive host‐pathogen coexistence, even when disease‐induced mortality is extremely high. We highlight the importance of integrating pathogen and population evolutionary interactions to better understand long‐term epidemic dynamics and evaluating disease control strategies.
Rabbit warrens: an important resource for invasive alien species in semi-arid Australia
Publisher: CSIRO Publishing
Date: 2023
DOI: 10.1071/WR22154
Diurnal and nocturnal grouping and foraging behaviors of free-ranging eastern grey kangaroos
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/ZO9950519
Abstract: Group size, methods of surveillance and foraging rates of free-ranging eastern grey kangaroos, Macropus giganteus, were compared between night and day, from data on 24-h followings of 24 in iduals. Kangaroos occurred in smaller groups in the dark but the reduction in group size took place before or around dusk, and could not be attributed to animals drifting apart after dark. Instead, changes in group size coincided with much movement by animals around dusk. Both males and females tended to spend less time surveying after dark, but females surveyed in fewer bouts at night than in the day. Females used the upright posture more at night than in the day this is a conspicuous posture but one that probably enhanced their view of the surroundings. Foraging rates of kangaroos were lower after dark than before dusk because of an increased search time per bite. There was no evidence that other foraging parameters, such as rare of movement whilst feeding, were affected by darkness. Eastern grey kangaroos are one of the most social and diurnally active species of macropod and their highly flexible social system of open-membership groups appears to allow in iduals to join and leave groups according to their foraging and safety requirements.
Isotopic niche variation in Tasmanian devils Sarcophilus harrisii with progression of devil facial tumor disease
Publisher: Wiley
Date: 06-2021
DOI: 10.1002/ECE3.7636
Abstract: Devil facial tumor disease (DFTD) is a transmissible cancer affecting Tasmanian devils Sarcophilus harrisii . The disease has caused severe population declines and is associated with demographic and behavioral changes, including earlier breeding, younger age structures, and reduced dispersal and social interactions. Devils are generally solitary, but social encounters are commonplace when feeding upon large carcasses. DFTD tumors can disfigure the jaw and mouth and so diseased in iduals might alter their diets to enable ingestion of alternative foods, to avoid conspecific interactions, or to reduce competition. Using stable isotope analysis (δ 13 C and δ 15 N) of whiskers, we tested whether DFTD progression, measured as tumor volume, affected the isotope ratios and isotopic niches of 94 infected Tasmanian devils from six sites in Tasmania, comprising four eucalypt plantations, an area of smallholdings and a national park. Then, using tissue from 10 devils s led before and after detection of tumors and 8 devils where no tumors were detected, we examined whether mean and standard deviation of δ 13 C and δ 15 N of the same in iduals changed between healthy and diseased states. δ 13 C and δ 15 N values were generally not related to tumor volume in infected devils, though at one site, Freycinet National Park, δ 15 N values increased significantly as tumor volume increased. Infection with DFTD was not associated with significant changes in the mean or standard deviation of δ 13 C and δ 15 N values in in idual devils s led before and after detection of tumors. Our analysis suggests that devils tend to maintain their isotopic niche in the face of DFTD infection and progression, except where ecological conditions facilitate a shift in diets and feeding behaviors, demonstrating that ecological context, alongside disease severity, can modulate the behavioral responses of Tasmanian devils to DFTD.
Extensive population decline in the Tasmanian devil predates European settlement and devil facial tumour disease
Publisher: The Royal Society
Date: 11-2014
Abstract: The Tasmanian devil ( Sarcophilus harrisii ) was widespread in Australia during the Late Pleistocene but is now endemic to the island of Tasmania. Low genetic ersity combined with the spread of devil facial tumour disease have raised concerns for the species’ long-term survival. Here, we investigate the origin of low genetic ersity by inferring the species' demographic history using temporal s ling with summary statistics, full-likelihood and approximate Bayesian computation methods. Our results show extensive population declines across Tasmania correlating with environmental changes around the last glacial maximum and following unstable climate related to increased ‘El Niño–Southern Oscillation’ activity.
Size Fractionation of Two‐Dimensional Sub‐Nanometer Thin Manganese Dioxide Crystals towards Superior Urea Electrocatalytic Conversion
Publisher: Wiley
Date: 16-02-2016
Abstract: A universal technique has been proposed to sort two-dimensional (2D) sub-nanometer thin crystals (manganese dioxide MnO2 and molybdenum disulfide MoS2 ) according to their lateral dimensions. This technique is based on tuning the zeta potential of their aqueous dispersions which induces the selective sedimentation of large-sized 2D crystals and leaves the small-sized counterparts in suspension. The electrocatalytic properties of as-obtained 2D ultrathin crystals are strongly dependent on their lateral size. As a proof-of-concept study, the small-sized MnO2 nanocrystals were tested as the electrocatalysts for the urea-oxidation reaction (UOR), which showed outstanding performance in both half reaction and full electrolytic cell. A mechanism study reveals the enhanced performance is associated with the remarkable structural properties of MnO2 including ultrathin (ca. 0.95 nm), laterally small-sized (50-200 nm), and highly exposed active centers.
Emergence, transmission and evolution of an uncommon enemy: Tasmanian devil facial tumour disease
Publisher: Cambridge University Press
Date: 14-11-2019
Prediction of crop production using drought indices at different time scales and climatic factors to manage drought risk
Publisher: Wiley
Date: 07-12-2012
Correction for Miller et al., Genetic diversity and population structure of the endangered marsupial Sarcophilus harrisii (Tasmanian devil)
Publisher: Proceedings of the National Academy of Sciences
Date: 05-10-2012
Character displacement in Australian dasyurid carnivores: Size relationships and prey size patterns
Publisher: Wiley
Date: 12-1997
Transmissible cancer in Tasmanian devils: localized lineage replacement and host population response
Publisher: The Royal Society
Date: 07-09-2015
Abstract: Tasmanian devil facial tumour disease (DFTD) is a clonally transmissible cancer threatening the Tasmanian devil ( Sarcophilus harrisii ) with extinction. Live cancer cells are the infectious agent, transmitted to new hosts when in iduals bite each other. Over the 18 years since DFTD was first observed, distinct genetic and karyotypic sublineages have evolved. In this longitudinal study, we investigate the associations between tumour karyotype, epidemic patterns and host demographic response to the disease. Reduced host population effects and low DFTD infection rates were associated with high prevalence of tetraploid tumours. Subsequent replacement by a diploid variant of DFTD coincided with a rapid increase in disease prevalence, population decline and reduced mean age of the population. Our results suggest a role for tumour genetics in DFTD transmission dynamics and epidemic outcome. Future research, for this and other highly pathogenic emerging infectious diseases, should focus on understanding the evolution of host and pathogen genotypes, their effects on susceptibility and tolerance to infection, and their implications for designing novel genetic management strategies. This study provides evidence for a rapid localized lineage replacement occurring within a transmissible cancer epidemic and highlights the possibility that distinct DFTD genetic lineages may harbour traits that influence pathogen fitness.
Darwin, the devil, and the management of transmissible cancers
Publisher: Wiley
Date: 08-10-2020
DOI: 10.1111/COBI.13644
Two decades of the impact of Tasmanian Devil Facial Tumour Disease (DFTD)
Publisher: Oxford University Press (OUP)
Date: 26-10-2018
DOI: 10.1093/ICB/ICY118
Abstract: The Tasmanian devil, a marsupial carnivore, has been restricted to the island state of Tasmania since its extinction on the Australian mainland about 3000 years ago. In the past two decades, this species has experienced severe population decline due to the emergence of devil facial tumor disease (DFTD), a transmissible cancer. During these 20 years, scientists have puzzled over the immunological and evolutionary responses by the Tasmanian devil to this transmissible cancer. Targeted strategies in population management and disease control have been developed as well as comparative processes to identify variation in tumor and host genetics. A multi-disciplinary approach with multi-institutional teams has produced considerable advances over the last decade. This has led to a greater understanding of the molecular pathogenesis and genomic classification of this cancer. New and promising developments in the Tasmanian devil’s story include evidence that most immunized, and some wild devils, can produce an immune response to DFTD. Furthermore, epidemiology combined with genomic studies suggest a rapid evolution to the disease and that DFTD will become an endemic disease. Since 1998 there have been more than 350 publications, distributed over 37 Web of Science categories. A unique endemic island species has become an international curiosity that is in the spotlight of integrative and comparative biology research.
Sympatric predator odour reveals a competitive relationship in size-structured mammalian carnivores
Publisher: Springer Science and Business Media LLC
Date: 25-07-2016
Marsupials of Australia’s Temperate and Subtropical Forests, Woodlands and Heathlands
Publisher: Springer International Publishing
Date: 2023
Is the Felixer cat control device safe for marsupial carnivores?
Publisher: CSIRO Publishing
Date: 10-08-2022
DOI: 10.1071/WR21175
Abstract: Context The Felixer grooming device (‘Felixer’) is a lethal method of feral cat control designed to be cost-effective and target specific. Aims This study aims to test the target specificity of the Felixer in Tasmania, with a particular focus on Tasmanian devil and quoll species due to the overlap in size, habitats and behaviour between these native carnivores and feral cats. Methods Our study deployed Felixer devices set in a non-lethal mode in nine field sites in Tasmania, one field site in New South Wales and two Tasmanian wildlife sanctuaries. Key results Our study recorded 4376 passes by identifiable vertebrate species including 528 Tasmanian devil passes, 507 spotted-tailed quoll passes and 154 eastern quoll passes. Our data showed that the Felixer can successfully differentiate quoll species from feral cats with spotted-tailed quolls and eastern quolls targeted in 0.19% and 0% of passes, respectively. However, Tasmanian devils and common wombats were targeted in 23.10% and 12% of passes, respectively, although s le size was low for common wombats (n = 25). Conclusions The Felixer could not reliably identify Tasmanian devils and possibly common wombats as non-target species. Further data is needed to confirm the potential for impacts on the common wombat and other potential non-target species in Tasmania, and the likelihood of the toxin being ingested by falsely targeted in iduals. Implications Our study suggest that the Felixer device is safe for use in the presence of two species of conservation concern, the eastern and spotted-tailed quoll. It also supports evidence from previous studies that the Felixer is unlikely to impact bettongs and potoroos. Use of Felixer devices across much of Tasmania would have to balance the conservation or economic benefits of cat control against potential impacts on Tasmanian devils. We suggest that active Felixer deployments be preceded by surveys to establish the range of species present at the control site, and the season of control considered carefully to minimise potential impacts on more susceptible juvenile animals. In addition, modifications to the Felixer device such as the proposed incorporation of AI technology should be tested against the Tasmanian devil and other non-target species.
Chronic stress in superb fairy‐wrens occupying remnant woodlands: Are noisy miners to blame?
Publisher: Wiley
Date: 10-06-2019
DOI: 10.1111/AEC.12785
Changing bird communities of an agricultural landscape: Declines in arboreal foragers, increases in large species
Publisher: The Royal Society
Date: 03-2020
DOI: 10.1098/RSOS.200076
Abstract: Birds are declining in agricultural landscapes around the world. The causes of these declines can be better understood by analysing change in groups of species that share life-history traits. We investigated how land-use change has affected birds of the Tasmanian Midlands, one of Australia's oldest agricultural landscapes and a focus of habitat restoration. We surveyed birds at 72 sites, some of which were previously surveyed in 1996–1998, and tested relationships of current patterns of abundance and community composition to landscape and patch-level environmental characteristics. Fourth-corner modelling showed strong negative responses of aerial foragers and exotics to increasing woodland cover arboreal foragers were positively associated with projective foliage cover and small-bodied species were reduced by the presence of a hyperaggressive species of native honeyeater, the noisy miner ( Manorina melanocephala ). Analysis of change suggests increases in large-bodied granivorous or carnivorous birds and declines in some arboreal foragers and nectarivores. Changes in species richness were best explained by changes in noisy miner abundance and levels of surrounding woodland cover. We encourage restoration practitioners to trial novel planting configurations that may confer resistance to invasion by noisy miners, and a continued long-term monitoring effort to reveal the effects of future land-use change on Tasmanian birds.
Niche differentiation among sympatric Australian dasyurid carnivores
Publisher: Oxford University Press (OUP)
Date: 05-2000
Greenhouse Gas Dynamics in a Salt-Wedge Estuary Revealed by High Resolution Cavity Ring-Down Spectroscopy Observations
Publisher: American Chemical Society (ACS)
Date: 22-11-2017
Protecting islands from pest invasion: optimal allocation of biosecurity resources between quarantine and surveillance
Publisher: Elsevier BV
Date: 05-2010
We need to go deeper: measuring electoral violence using convolutional neural networks and social media
Publisher: Cambridge University Press (CUP)
Date: 26-08-2020
DOI: 10.1017/PSRM.2020.32
Abstract: Electoral violence is conceived of as violence that occurs contemporaneously with elections, and as violence that would not have occurred in the absence of an election. While measuring the temporal aspect of this phenomenon is straightforward, measuring whether occurrences of violence are truly related to elections is more difficult. Using machine learning, we measure electoral violence across three elections using disaggregated reporting in social media. We demonstrate that our methodology is more than 30 percent more accurate in measuring electoral violence than previously utilized models. Additionally, we show that our measures of electoral violence conform to theoretical expectations of this conflict more so than those that exist in event datasets commonly utilized to measure electoral violence including ACLED, ICEWS, and SCAD. Finally, we demonstrate the validity of our data by developing a qualitative coding ontology.
A systematic global review of mammalian carnivore responses to production forests
Publisher: Cold Spring Harbor Laboratory
Date: 27-03-2023
DOI: 10.1101/2023.03.26.534289
Abstract: Unmodified forests are increasingly rare worldwide, with forestry a major contributor to habitat modification. Extending conservation practices beyond protected areas is important to conserve forest ecosystems. We investigate the response of native mammalian carnivores (both Order Carnivora and Family Dasyuridae) to production forests globally, including harvested native forest and timber plantations. We examine how carnivores recorded in production forests use these forests versus other land uses, particularly native and unharvested forest how habitat use relates to threatened status, body size, diet, and harvesting method carnivore responses to habitat features within production forests and carnivore denning, breeding, and predation behaviour in production forests. We review 294 studies recording 132 carnivore species in production forests. Carnivores generally show higher use of native and unharvested forests and lower use of agricultural land than production forests. Threatened species and large carnivores respond more negatively to production forests than non-threatened species and small carnivores respectively. Hypercarnivores respond more negatively than omnivores to plantations compared to native forest, but there was no difference in the use of harvested and unharvested native forest between these dietary groups. Surprisingly, a high proportion of carnivore species use clearfelled more than unharvested native forest. In forest with partial harvesting or reduced-impact logging, most species show no difference in use between harvested and unharvested forest. Carnivores generally respond positively to habitat features such as riparian areas and coarse woody debris. Several carnivores were recorded denning and breeding in production forests. Production forests often influence the prey availability, hunting success, and diet of carnivores. We show that many carnivores use production forests, and how they respond to production forestry varies with species traits. We recommend that production forests are managed as valuable carnivore habitat, and highlight strategies to enhance the use of these forests by carnivores.
Groundwater Discharge as a Source of Dissolved Carbon and Greenhouse Gases in a Subtropical Estuary
Publisher: Springer Science and Business Media LLC
Date: 03-11-2016
Quantifying 25 years of disease‐caused declines in Tasmanian devil populations: host density drives spatial pathogen spread
Publisher: Wiley
Date: 27-02-2021
DOI: 10.1111/ELE.13703
Abstract: Infectious diseases are strong drivers of wildlife population dynamics, however, empirical analyses from the early stages of pathogen emergence are rare. Tasmanian devil facial tumour disease (DFTD), discovered in 1996, provides the opportunity to study an epizootic from its inception. We use a pattern‐oriented diffusion simulation to model the spatial spread of DFTD across the species' range and quantify population effects by jointly modelling multiple streams of data spanning 35 years. We estimate the wild devil population peaked at 53 000 in 1996, less than half of previous estimates. DFTD spread rapidly through high‐density areas, with spread velocity slowing in areas of low host densities. By 2020, DFTD occupied % of the species' range, causing 82% declines in local densities and reducing the total population to 16 900. Encouragingly, our model forecasts the population decline should level‐off within the next decade, supporting conservation management focused on facilitating evolution of resistance and tolerance.
The function of vigilance in sympatric marsupial carnivores: The eastern quoll and the Tasmanian devil
Publisher: Elsevier BV
Date: 11-1998
Abstract: Sympatric marsupial carnivore (Marsupialia: Dasyuridae) species experience different levels of risk of predation and competition as a consequence of different body size and feeding adaptations. The small eastern quoll, Dasyurus viverrinus, is preyed upon by owls and is aggressively displaced from carcasses by its larger competitor and potential predator, the Tasmanian devil, Sarcophilus laniarius. Devils have no known predators but this specialized scavenger experiences intense intraspecific competition. I studied the vigilance behaviour of in iduals of these species feeding on carcasses. (1) Eastern quolls were more vigilant in the presence than in the absence of devils, suggesting that their vigilance functions to detect predators/competitors. (2) Devils showed a decrease in vigilance with increasing body size and age, and a trend towards a decrease with increasing group size. These are the same patterns expected if vigilance was in response to predation risk, although devils have no predators. Vigilance behaviour did not change in the presence of eastern quolls, suggesting that vigilance is not directed towards interspecific competitors. (3) As expected from their greater risk of predation and injury from a larger competitor, eastern quolls appeared to invest more in vigilance than devils did: they used vigilance postures that gave better visibility but disrupted feeding more. Copyright 1998 The Association for the Study of Animal Behaviour.
Transcriptomics of Tasmanian Devil (Sarcophilus Harrisii) Ear Tissue Reveals Homogeneous Gene Expression Patterns across a Heterogeneous Landscape
Publisher: MDPI AG
Date: 12-10-2019
Abstract: In an era of unprecedented global change, exploring patterns of gene expression among wild populations across their geographic range is crucial for characterizing adaptive potential. RNA-sequencing studies have successfully characterized gene expression differences among populations experiencing ergent environmental conditions in a wide variety of taxa. However, few of these studies have identified transcriptomic signatures to multivariate, environmental stimuli among populations in their natural environments. Herein, we aim to identify environmental and sex-driven patterns of gene expression in the Tasmanian devil (Sarcophilus harrisii), a critically endangered species that occupies a heterogeneous environment. We performed RNA-sequencing on ear tissue biopsies from adult male and female devils from three populations at the extremes of their geographic range. There were no transcriptome-wide patterns of differential gene expression that would be suggestive of significant, environmentally-driven transcriptomic responses. The general lack of transcriptome-wide variation in gene expression levels across the devil’s geographic range is consistent with previous studies that documented low levels of genetic variation in the species. However, genes previously implicated in local adaptation to abiotic environment in devils were enriched for differentially expressed genes. Additionally, three modules of co-expressed genes were significantly associated with either population of origin or sex.
Continuing decline of the eastern quoll in Tasmania
Publisher: Cold Spring Harbor Laboratory
Date: 12-03-2022
DOI: 10.1101/2022.03.10.483855
Abstract: Like many other Australian mammals, the eastern quoll ( Dasyurus viverrinus) was widespread on the Australian mainland but went extinct there during the 20th century. The species remained abundant in Tasmania until a rapid decline occurred from 2001 to 2003, coinciding with a period of unsuitable weather. We provide an updated analysis of eastern quoll population trends in Tasmania by analysing a Tasmania-wide time series of annual spotlight counts (1985-2019). Eastern quolls were widespread and abundant in Tasmania until the early 2000s. A distinct change occurred in the early 2000s in the east and northeast, which led to severe population reductions. However, we present new evidence of an earlier decline in the north (mid-1990s) and a more recent decline around 2009 in the south. Range-wide declines have continued unabated during the last decade, resulting in a ∼67% decline (since the late 1990s) in the area with high quoll abundance. Although the timing of the major decline in the early 2000s coincided with unfavourable weather, the continuing decline and more recent change points suggest other causes are also involved. We can no longer assume that the existence of eastern quolls in Tasmania ensures the species’ long-term survival, highlighting the urgent need to increase efforts to conserve the remaining populations in Tasmania.
The role of connectivity in Australian conservation
Publisher: CSIRO Publishing
Date: 2004
DOI: 10.1071/PC040266
Abstract: The existing system of nature reserves in Australia is inadequate for the long-term conservation and restoration of native biological ersity because it fails to accommodate, among other elements, large scale and long-term ecological processes and change, including physical and biotic transport in the landscape. This paper is an overview of the connectivity elements that inform a scientific framework for significantly improving the prospects for the long-term conservation of Australia's bio ersity. The framework forms the basis for the WildCountry programme. This programme has identified connectivity at landscape, regional and continental scales as a critical component of an effective conservation system. Seven categories of ecological phenomena are reviewed that require landscape permeability and that must be considered when planning for the maintenance of biological ersity and ecological resilience in Australia: (1) trophic relations at regional scales (2) animal migration, dispersal, and other large scale movements of in iduals and propagules (3) fire and other forms of disturbance at regional scales (4) climate variability in space and time and human forced rapid climate change (5) hydroecological relations and flows at all scales (6) coastal zone fluxes of organisms, matter, and energy and, (7) spatially-dependent evolutionary processes at all scales. Finally, we mention eight cross-cutting themes that further illuminate the interactions and implications of the seven connectivity-related phenomena for conservation assessment, planning, research, and management, and we suggest how the results might be applied by analysts, planners, scientists, and community conservationists.
Marsupials of Australia’s Temperate and Subtropical Forests, Woodlands and Heathlands
Publisher: Springer International Publishing
Date: 2023
Sarcophilus harrisii (Dasyuromorphia: Dasyuridae)
Publisher: Oxford University Press (OUP)
Date: 05-2017
Disturbance of eucalypt forests alters the composition, function, and assembly of soil microbial communities
Publisher: Oxford University Press (OUP)
Date: 22-07-2023
Abstract: Forest disturbance has well-characterized effects on soil microbial communities in tropical and northern hemisphere ecosystems, but little is known regarding effects of disturbance in temperate forests of the southern hemisphere. To address this question, we collected soils from intact and degraded Eucalyptus forests along an east–west transect across Tasmania, Australia, and characterized prokaryotic and fungal communities using licon sequencing. Forest degradation altered soil microbial community composition and function, with consistent patterns across soil horizons and regions of Tasmania. Responses of prokaryotic communities included decreased relative abundance of Acidobacteriota, nitrifying archaea, and methane-oxidizing prokaryotes in the degraded forest sites, while fungal responses included decreased relative abundance of some saprotrophic taxa (e.g. litter saprotrophs). Forest degradation also reduced network connectivity in prokaryotic communities and increased the importance of dispersal limitation in assembling both prokaryotic and fungal communities, suggesting recolonization dynamics drive microbial composition following disturbance. Further, changes in microbial functional groups reflected changes in soil chemical properties—reductions in nitrifying microorganisms corresponded with reduced NO3-N pools in the degraded soils. Overall, our results show that soil microbiota are highly responsive to forest degradation in eucalypt forests and demonstrate that microbial responses to degradation will drive changes in key forest ecosystem functions.
Contemporary and historical selection in Tasmanian devils (Sarcophilus harrisii) support novel, polygenic response to transmissible cancer
Publisher: Cold Spring Harbor Laboratory
Date: 07-08-2020
DOI: 10.1101/2020.08.07.241885
Abstract: Tasmanian devils ( Sarcophilus harrisii ) are evolving in response to a unique transmissible cancer, devil facial tumour disease (DFTD), first described in 1996. Persistence of wild populations and the recent emergence of a second independently evolved transmissible cancer suggest that transmissible cancers may be a recurrent feature in devils. Here we compared signatures of selection across temporal scales to determine whether genes or gene pathways under contemporary selection (6-8 generations) have also been subject to historical selection (65-85 million years), and test for recurrent selection in devils. First, we used a targeted sequencing approach, RAD-capture, to identify genomic regions subject to rapid evolution in approximately 2,500 devils in six populations as DFTD spread across the species range. We documented genome-wide contemporary evolution, including 186 candidate genes related to cell cycling and immune response. Then we used a molecular evolution approach to identify historical positive selection in devils compared to other marsupials and found evidence of selection in 1,773 genes. However, we found limited overlap across time scales, with historical selection detected in only 16 contemporary candidate genes, and no overlap in enriched functional gene sets. Our results are consistent with a novel, multi-locus evolutionary response of devils to DFTD. Our results can inform management actions to conserve adaptive potential of devils by identifying high priority targets for genetic monitoring and maintenance of functional ersity in managed populations.
Activity and social interactions in a wideranging specialist scavenger, the Tasmanian devil (Sarcophilus harrisii), revealed by animalborne video collars
Publisher: Public Library of Science (PLoS)
Date: 23-03-2020
Rapid gain and loss of predator recognition by an evolutionarily naïve lizard
Publisher: Wiley
Date: 06-02-2022
DOI: 10.1111/AEC.13148
Abstract: The introduction of mammalian predators often results in loss of native bio ersity due to naiveté of native prey to novel predators. In New Zealand, an island system with virtually no native mammalian predators, introduced mammalian predators threaten a large proportion of the native fauna. A critical step in adapting to introduced predators is the ability to recognize and respond to a novel predation threat. Whether New Zealand's lizards can do this has received little attention. We compared the basking behaviour of native McCann's skinks ( Oligosoma maccanni ) when exposed to a live cat ( Felis catus ), cat body odour, a model raptor (representing a coevolved predator) or procedural controls. We inferred predator recognition from reductions in in idual basking and higher selection for basking sites with greater refuge availability. We tested these behavioural responses for two skink populations: one from an area with high abundance of mammalian predators including feral cats and the other from a fenced conservation reserve where predators have been excluded for over 10 years (3–4 skink generations). Skinks from the high‐predator population reduced basking when exposed to cat and raptor cues, whereas skinks from the predator‐free population did not. These results suggest that within approximately 150 years of exposure to novel predators, McCann's skinks might be able to recognize the threat posed by invasive mammals. However, they also demonstrate that predator recognition and antipredator behaviours may not necessarily be retained once gained. The rapid loss of basking‐related antipredator behaviours might reflect the high fitness costs of reduced basking for this species. Our results indicate that the behavioural response of skinks is flexible and that skinks may maximize in idual fitness by balancing the risk of predation with the costs of antipredator behaviours.
Porewater exchange drives trace metal, dissolved organic carbon and total dissolved nitrogen export from a temperate mangrove wetland
Publisher: Elsevier BV
Date: 10-2019
Dominant carnivore loss benefits native avian and invasive mammalian scavengers
Publisher: The Royal Society
Date: 26-10-2022
Abstract: Scavenging by large carnivores is integral for ecosystem functioning by limiting the build-up of carrion and facilitating widespread energy flows. However, top carnivores have declined across the world, triggering trophic shifts within ecosystems. Here, we compare findings from previous work on predator decline against areas with recent native mammalian carnivore loss. Specifically, we investigate top-down control on utilization of experimentally placed carcasses by two mesoscavengers—the invasive feral cat and native forest raven. Ravens profited most from carnivore loss, scavenging for five times longer in the absence of native mammalian carnivores. Cats scavenged on half of all carcasses in the region without dominant native carnivores. This was eight times more than in areas where other carnivores were at high densities. All carcasses persisted longer than the three-week monitoring period in the absence of native mammalian carnivores, while in areas with high carnivore abundance, all carcasses were fully consumed. Our results reveal that top-carnivore loss lifies impacts associated with carnivore decline—increased carcass persistence and carrion access for smaller scavengers. This suggests that even at low densities, native mammalian carnivores can fulfil their ecological functions, demonstrating the significance of global carnivore conservation and supporting management approaches, such as trophic rewilding.
Global change influences scavenging and carrion decomposition
Publisher: Elsevier BV
Date: 10-2023
Wildlife disease ecology in changing landscapes: Mesopredator release and toxoplasmosis
Publisher: Elsevier BV
Date: 12-2013
Reduced effect of Tasmanian devil facial tumor disease at the disease front
Publisher: Wiley
Date: 06-10-2012
DOI: 10.1111/J.1523-1739.2011.01747.X
Abstract: Pathogen-driven declines in animal populations are increasingly regarded as a major conservation issue. The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction by devil facial tumor disease, a unique transmissible cancer. The disease is transmitted through direct transfer of tumor cells, which is possible because the genetic ersity of Tasmanian devils is low, particularly in the major histocompatibility complex genes of the immune system. The far northwest of Tasmania now holds the last remaining disease-free wild devil populations. The recent discovery of unique major histocompatibility complex genotypes in the northwestern region of Tasmania has raised the possibility that some animals may be resilient to the disease. We examined the differences in the epidemiology and population effects of devil facial tumor disease at 3 well-studied affected sites in eastern Tasmania and 1 in western Tasmania (West Pencil Pine). In contrast to the 3 eastern sites, there has been no rapid increase in disease prevalence or evidence of population decline at West Pencil Pine. Moreover, this is the only onsite at which the population age structure has remained unaltered 4 years after the first detection of disease. The most plausible explanations for the substantial differences in population effects and epidemiology of the disease between eastern and western sites are geographic differences in genotypes or phenotypes of devils and functional differences between tumor strains in the 2 regions. We suggest that conservation efforts focus on identifying whether either or both these explanations are correct and then, if resistance alleles exist, to attempt to spread the resistant alleles into affected populations. Such assisted selection has rarely been attempted for the management of wildlife diseases, but it may be widely applicable.
Long-Distance Movements of Feral Cats in Semi-Arid South Australia and Implications for Conservation Management
Publisher: MDPI AG
Date: 31-10-2021
DOI: 10.3390/ANI11113125
Abstract: Movements that extend beyond the usual space use of an animal have been documented in a range of species and are particularly prevalent in arid areas. We present long-distance movement data on five feral cats (Felis catus) GPS/VHF-collared during two different research projects in arid and semi-arid Australia. We compare these movements with data from other feral cat studies. Over a study period of three months in the Ikara-Flinders Ranges National Park, 4 out of 19 collared cats moved to sites that were 31, 41, 53 and 86 km away. Three of the cats were males, one female their weight was between 2.1 and 4.1 kg. Two of the cats returned to the area of capture after three and six weeks. During the other study at Arid Recovery, one collared male cat (2.5 kg) was relocated after two years at a distance of 369 km from the area of collar deployment to the relocation area. The movements occurred following three years of record low rainfall. Our results build on the knowledge base of long-distance movements of feral cats reported at arid study sites and support the assertion that landscape-scale cat control programs in arid and semi-arid areas need to be of a sufficiently large scale to avoid rapid reinvasion and to effectively reduce cat density. Locally, cat control strategies need to be adjusted to improve coverage of areas highly used by cats to increase the efficiency of control operations.
A new PCR assay for reliable molecular sexing of endangered Tasmanian devils (Sarcophilus harrisii) from non-invasive genetic samples
Publisher: Springer Science and Business Media LLC
Date: 16-11-2011
Individual and temporal variation in pathogen load predicts long-term impacts of an emerging infectious disease
Publisher: Cold Spring Harbor Laboratory
Date: 15-08-2018
DOI: 10.1101/392324
Abstract: Emerging infectious diseases increasingly threaten wildlife populations. Most studies focus on managing short-term epidemic properties, such as controlling early outbreaks. Predicting long-term endemic characteristics with limited retrospective data is more challenging. We used in idual-based modelling informed by in idual variation in pathogen load and transmissibility to predict long-term impacts of a lethal, transmissible cancer on Tasmanian devil ( Sarcophilus harrisii ) populations. For this, we employed Approximate Bayesian Computation to identify model scenarios that best matched known epidemiological and demographic system properties derived from ten years of data after disease emergence, enabling us to forecast future system dynamics. We show that the dramatic devil population declines observed thus far are likely attributable to transient dynamics. Only 21% of matching scenarios led to devil extinction within 100 years following devil facial tumour disease (DFTD) introduction, whereas DFTD faded out in 57% of simulations. In the remaining 22% of simulations, disease and host coexisted for at least 100 years, usually with long-period oscillations. Our findings show that pathogen extirpation or host-pathogen coexistence are much more likely than the DFTD-induced devil extinction, with crucial management ramifications. Accounting for in idual-level disease progression and the long-term outcome of devil-DFTD interactions at the population-level, our findings suggest that immediate management interventions are unlikely to be necessary to ensure the persistence of Tasmanian devil populations. This is because strong population declines of devils after disease emergence do not necessarily translate into long-term population declines at equilibria. Our modelling approach is widely applicable to other host-pathogen systems to predict disease impact beyond transient dynamics.
Tasmanian devil facial tumor-derived extracellular vesicles reveal mesenchymal transition markers and adhesion molecules related to metastasis
Publisher: Cold Spring Harbor Laboratory
Date: 19-10-2020
DOI: 10.1101/2020.10.18.344721
Abstract: Tasmanian devils are threatened with extinction by Devil Facial Tumor Disease (DFTD), which consists of two genetically independent transmissible cancers (DFT1 and DFT2). Both cancers typically cause death due to metastases. However, the mechanisms underpinning DFTD metastasis are not well understood. The nano-sized, membrane-enclosed extracellular vesicles (EVs) released by cancer cells have been implicated in metastasis, thus EVs may yield insights into DFTD metastasis. Here, we characterized EVs derived from cultured DFT1, DFT2, and devil fibroblast cells. The proteome of EVs was determined using data independent acquisition mass spectrometry and an in-house spectral library of ,500 proteins. Relative to EVs from fibroblast cells, EVs from both DFT1 and DFT2 cell lines expressed higher levels of proteins associated with cell adhesion and focal adhesion functions. Furthermore, hallmark proteins of epithelial mesenchymal transition, which are associated with increased metastatic features in some cancers, were enriched in DFT2 EVs relative to DFT1 EVs, suggesting differential aggressiveness between the cancers and a target for novel differential diagnosis biomarkers. This first EV-based investigation of DFTD increases our understanding of the cancers’ EVs and their possible involvement in the metastatic process. As EVs are found in body fluids, these results offer potential for non-invasive biomarkers for DFTD.
Seasonal, demographic and density-related patterns of contact between Tasmanian devils (Sarcophilus harrisii): Implications for transmission of devil facial tumour disease
Publisher: Wiley
Date: 08-2008
Variants in the host genome may inhibit tumour growth in devil facial tumours: Evidence from genome-wide association
Publisher: Springer Science and Business Media LLC
Date: 24-03-2017
DOI: 10.1038/S41598-017-00439-7
Abstract: Devil facial tumour disease (DFTD) has decimated wild populations of Tasmanian devils ( Sarcophilus harrisii ) due to its ability to avoid immune detection and pass from host to host by biting. A small number of devils have been observed to spontaneously recover from the disease which is otherwise fatal. We have sequenced the genomes of these rare cases and compared them to the genomes of devils who succumbed to the disease. Genome-wide association, based on this limited s ling, highlighted two key genomic regions potentially associated with ability to survive DFTD. Following targeted genotyping in additional s les, both of these loci remain significantly different between cases and controls, with the PAX3 locus retaining significance at the 0.001 level, though genome-wide significance was not achieved. We propose that PAX3 may be involved in a regulatory pathway that influences the slowing of tumour growth and may allow more time for an immune response to be mounted in animals with regressed tumours. This provides an intriguing hypothesis for further research and could provide a novel route of treatment for this devastating disease.
Trophic rewilding establishes a landscape of fear: Tasmanian devil introduction increases risk-sensitive foraging in a key prey species
Publisher: Wiley
Date: 19-09-2019
DOI: 10.1111/ECOG.04635
Harnessing the power of ecological interactions to reduce the impacts of feral cats
Publisher: Informa UK Limited
Date: 02-01-2019
Correction to: ‘A triple threat: high population density, high foraging intensity and flexible habitat preferences explain high impact of feral cats on prey’ (2021) by Hamer et al.
Publisher: The Royal Society
Date: 16-11-2022
Body temperatures and activity patterns of Tasmanian devils (Sarcophilus harrisii) and eastern quolls (Dasyurus viverrinus) through a subalpine winter
Publisher: University of Chicago Press
Date: 1997
DOI: 10.1086/639541
Abstract: During a field study of carnivorous dasyurid marsupials in subalpine Tasmania, the trapping success for Tasmanian devils (Sarcophilus harrisii), but not for spotted-tailed quolls (Dasyurus maculatus) or eastern quolls (Dasyurus viverrinus), was significantly lower when winter weather conditions turned to sleet or snow or when deep snow lay on the ground. This field study was instigated to determine if devils and eastern quolls spend more time in burrows in severe weather conditions and if they enter torpor. Torpor is known to occur in eutherian mammals as large as devils and in a similar-sized congeneric marsupial, the western quoll (Dasyurus geoffroyi). Using radiotelemetry, body temperatures of Tasmanian devils and eastern quolls ranging freely in their natural habitat were monitored throughout winter. Neither species was observed in torpor, even under prolonged severe weather conditions, and the number of hours spent active not did differ between summer and winter or between moderate and severe winter weather conditions. Body temperatures averaged 36.5 degrees C (SD = 0.079, range of 33.5 degrees-38.6 degrees C) for the three male eastern quolls and 35.7 degrees C (SD = 0.575, range of 31.3 degrees-37.5 degrees C) for the four (male and female) devils. A diel cycle in body temperature occurred in both species temperatures rose each evening when animals became active, remained high throughout the night despite ambient temperatures falling to the diel minima, and were lower during the day when the in iduals were inactive in dens. The litude of this cycle was greater in eastern quolls (1.1 degrees C, SD = 0.142) than in devils (0.6 degree C, SD = 0.252).
Disease swamps molecular signatures of genetic-environmental associations to abiotic factors in Tasmanian devil (Sarcophilus harrisii) populations
Publisher: Cold Spring Harbor Laboratory
Date: 24-09-2019
DOI: 10.1101/780122
Abstract: Landscape genomics studies focus on identifying candidate genes under selection via spatial variation in abiotic environmental variables, but rarely by biotic factors such as disease. The Tasmanian devil ( Sarcophilus harrisii ) is found only on the environmentally heterogeneous island of Tasmania and is threatened with extinction by a nearly 100% fatal, transmissible cancer, devil facial tumor disease (DFTD). Devils persist in regions of long-term infection despite epidemiological model predictions of species’ extinction, suggesting possible adaptation to DFTD. Here, we test the extent to which spatial variation and genetic ersity are associated with the abiotic environment and/or by DFTD. We employ genetic-environment association (GEAs) analyses using a RAD-capture panel consisting of 6,886 SNPs from 3,286 in iduals s led pre- and post-disease arrival. Pre-disease, we find significant correlations of allele frequencies with environmental variables, including 349 unique loci linked to 64 genes, suggesting local adaptation to abiotic environment. Following DFTD arrival, however, we detected few of the pre-disease candidate loci, but instead frequencies of candidate loci linked to 14 genes correlated with disease prevalence. Loss of apparent signal of abiotic local adaptation following disease arrival suggests sw ing by the strong selection imposed by DFTD. Further support for this result comes from the fact that post-disease candidate loci are in linkage disequilibrium with genes putatively involved in immune response, tumor suppression and apoptosis. This suggests the strength GEA associations of loci with the abiotic environment are sw ed resulting from the rapid onset of a biotic selective pressure.
Contemporary and historical selection in Tasmanian devils ( Sarcophilus harrisii ) support novel, polygenic response to transmissible cancer
Publisher: The Royal Society
Date: 26-05-2021
Abstract: Tasmanian devils ( Sarcophilus harrisii ) are evolving in response to a unique transmissible cancer, devil facial tumour disease (DFTD), first described in 1996. Persistence of wild populations and the recent emergence of a second independently evolved transmissible cancer suggest that transmissible cancers may be a recurrent feature in devils. Here, we compared signatures of selection across temporal scales to determine whether genes or gene pathways under contemporary selection (six to eight generations) have also been subject to historical selection (65–85 Myr). First, we used targeted sequencing, RAD-capture, in approximately 2500 devils in six populations to identify genomic regions subject to rapid evolution. We documented genome-wide contemporary evolution, including 186 candidate genes related to cell cycling and immune response. Then we used a molecular evolution approach to identify historical positive selection in devils compared to other marsupials and found evidence of selection in 1773 genes. However, we found limited overlap across time scales, with only 16 shared candidate genes, and no overlap in enriched functional gene sets. Our results are consistent with a novel, multi-locus evolutionary response of devils to DFTD. Our results can inform conservation by identifying high priority targets for genetic monitoring and guiding maintenance of adaptive potential in managed populations.
The Devil is in the detail: Conservation biology, animal philosophies and the role of animal ethics committees
Publisher: Royal Zoological Society of New South Wales
Date: 2012
DOI: 10.7882/FS.2012.040
Movements and habitat selection of a marsupial carnivore in a modified landscape
Publisher: Cold Spring Harbor Laboratory
Date: 05-03-2023
DOI: 10.1101/2023.03.05.531208
Abstract: Landscape modification is a major threat to carnivores worldwide, but modified landscapes can also provide important habitat for these species, as protected areas alone are insufficient. Understanding how carnivores move through modified landscapes, such as production forests, can inform management strategies to improve the value of these landscapes to carnivores. Little is known about habitat selection by marsupial carnivores in production forests, where they occupy a similar ecological niche to their more well-studied eutherian counterparts. We used GPS tracking, Hidden Markov Models, and Manly’s selection ratios to identify the habitat selected in 3 movement states indicating resting/feeding, foraging, and travel by the largest marsupial carnivore, the Tasmanian devil ( Sarcophilus harrisii ), in a timber plantation-dominated landscape. Devils did not show preferences for any of native forest, native grassland, and plantation in any movement state. Within plantations, devils preferred a plantation age of 4–7 years (selection ratio [ wi ] = 1.52) and slightly avoided older plantations (8–13 years wi = 0.74, 14+ years wi = 0.65). Devils preferred roads (state 1: wi = 2.71, state 2: wi = 2.48, state 3: wi = 2.97) and plantation edges (state 1: wi = 2.38, state 2: wi = 2.24, state 3: wi = 2.78) in all movement states, and moved faster on roads (0.06 [95% CI 0.04 to 0.09] m.sec -1 ) and edges (0.08 [0.06 to 0.10] m.sec -1 ) than away from them, indicating they use them for foraging and travel. No measured habitat variables influenced devil home range size. To support devils in plantation landscapes, we recommend maintaining a heterogeneous landscape of different plantation ages and native remnants and reducing the risk of vehicle collisions by minimizing forestry traffic at night. Tasmanian devils share similar adaptable traits to generalist eutherian carnivore species in their use of modified landscapes. Plantations can provide valuable habitat for this and other threatened predator species.
Coexistence of temporally partitioned spiny mice: Roles of habitat structure and foraging behavior
Publisher: Wiley
Date: 08-2001
The effects of weather variability on patterns of genetic diversity in Tasmanian bettongs
Publisher: Wiley
Date: 15-03-2021
DOI: 10.1111/MEC.15847
Abstract: While the effects of climate (long‐term, prevailing weather) on species abundance, range and genetic ersity have been widely studied, short‐term, localized variations in atmospheric conditions (i.e., weather) can also rapidly alter species’ geographical ranges and population sizes, but little is known about how they affect genetic ersity. We investigated the relationship between weather and range‐wide genetic ersity in a marsupial, Bettongia gaimardi , using dynamic species distribution models (SDMs). Genetic ersity was lower in parts of the range where the weather‐based SDM predicted high variability in probability of B. gaimardi occurrence during 1950–2009. This is probably an effect of lower population sizes and extinction–recolonization cycles in places with highly variable weather. Spatial variation in genetic ersity was also better predicted by mean probabilities of B. gaimardi occurrence from weather‐ than climate‐based SDMs. Our results illustrate the importance of weather in driving population dynamics and species distributions on decadal timescales and thereby in affecting genetic ersity. Modelling the links between changing weather patterns, species distributions and genetic ersity will allow researchers to better forecast biological impacts of climate change.
Diel changes in numbers of seabirds occupying Cays on the Swain Reefs, Great Barrier Reef, Australia
Publisher: Smithsonian Institution
Date: 2005
Lessons from the Looming Extinction of the Tasmanian Devil
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/PC080151
Abstract: Extinction in the wild is now regarded as likely for the Tasmanian Devil Sarcophilus harrissi. In 1996, a disease, Devil Facial Tumour Disease (DFTD), was seen in a Devil in the wild. By mid-2008, the population had declined by about 70%, and the disease was spreading rapidly from east to west across Tasmania. DFTD is an infectious cancer, passed from one Devil to another principally, or entirely, by biting. The bite implants the cancer cells the low genetic ersity in the Tasmanian Devil population from previous population bottlenecks or selective sweeps means that those cancer cells are not recognized by the immune system and the cancer grows in the infected Devil. Estimates of the time to extinction in the wild range from about 20 to 35 years. If, however, there are resistant genotypes within the Devil population then extinction in the wild may be averted, with numbers augmented through captive breeding programmes and active management to spread these genotypes in the wild.
Disease swamps molecular signatures of genetic‐environmental associations to abiotic factors in Tasmanian devil ( Sarcophilus harrisii ) populations
Publisher: Wiley
Date: 03-06-2020
DOI: 10.1111/EVO.14023
Landscape genetics of the Tasmanian devil: implications for spread of an infectious cancer
Publisher: Springer Science and Business Media LLC
Date: 27-05-2017
A native apex predator limits an invasive mesopredator and protects native prey: Tasmanian devils protecting bandicoots from cats
Publisher: Wiley
Date: 13-02-2020
DOI: 10.1111/ELE.13473
Disease induced changes in gene flow patterns among Tasmanian devil populations
Publisher: Elsevier BV
Date: 09-2013
Ecosystem restoration - a public health intervention
Publisher: Springer Science and Business Media LLC
Date: 23-06-2020
Groundwater quality assessment using the Water Quality Index and GIS in Saveh-Nobaran aquifer, Iran
Publisher: Springer Science and Business Media LLC
Date: 08-09-2014
Assessing the value of restoration plantings for wildlife in a temperate agricultural landscape
Publisher: Wiley
Date: 12-07-2021
DOI: 10.1111/REC.13470
Abstract: Habitat loss is a primary cause of population decline for 85% of species recognized as threatened by the International Union for Conservation of Nature. Ecological restoration can mitigate and reverse the effects of habitat loss on wildlife, but many restoration programs lack a systematic approach to monitoring outcomes, if indeed restoration sites are monitored at all. Here, we evaluate the response of wildlife to restoration plantings in an agricultural landscape in Tasmania, Australia, five years after their establishment. We surveyed three faunal groups—ground‐dwelling invertebrates, birds and terrestrial mammals—and compared community composition in plantings with those of nearby livestock pasture and remnant woodlands. Habitat type had some influence on invertebrate communities with more pollinators, but fewer nectivores (predominantly Lepidoptera) and engulf predators in riparian plantings than in paddocks. In comparison, nonriparian plantings had more nectivores and pollinators and a greater proportion of small‐bodied invertebrates than in paddocks. Invertebrate biomass was positively associated with the presence of large ground‐foraging birds. Habitat type had a significant effect on the composition of bird communities in nonriparian areas, with small native species more abundant in plantings than in paddocks. Endangered mammal species were recorded using planting sites, including eastern bettongs and spotted‐tailed quolls. We describe possible trajectories to inform adaptive management of local restoration efforts. Our study provides a rare ex le that considers the response of multiple faunal groups to restoration concurrently and highlights differences in wildlife communities between restoring and reference habitats that are likely to impact ecosystem services.
Detecting selection on temporal and spatial scales: A genomic time-series assessment of selective responses to devil facial tumor disease
Publisher: Public Library of Science (PLoS)
Date: 03-2016
Low MHC class II diversity in the Tasmanian devil (Sarcophilus harrisii)
Publisher: Springer Science and Business Media LLC
Date: 31-03-2012
DOI: 10.1007/S00251-012-0614-4
Abstract: The largest remaining carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii), is currently under threat of extinction due to a fatal contagious cancer-devil facial tumour disease. Low major histocompatibility complex (MHC) class I ersity is believed to have contributed to the transmission of the tumour allograft through devil populations. Here, we report low MHC class II variability in this species, with DA β chain genes (Saha-DAB1, 2 and 3) exhibiting very limited ersity and the sole α chain gene (Saha-DAA) monomorphic. Three, six and three alleles were found at Saha-DAB1, 2 and 3, respectively, with a predominant allele found at each locus. Heterozygosity at these three loci is low in the eastern population and modestly higher in northwestern in iduals. The results are indicative of a selective sweep likely due to an infectious disease resulting in the fixation of selectively favoured alleles and depletion of genetic ersity at devil class II loci. Several attempts were made to isolate the other marsupial classical class II gene family, namely, DB, resulting in only one DBB pseudogene being found. These findings further support the view that this species has a compromised capacity to respond to pathogen evolution, emerging infectious diseases and environmental changes.
High porewater exchange in a mangrove-dominated estuary revealed from short-lived radium isotopes
Publisher: Elsevier BV
Date: 10-2017
Conservation implications of limited genetic diversity and population structure in Tasmanian devils (Sarcophilus harrisii)
Publisher: Springer Science and Business Media LLC
Date: 07-02-2017
Groundwater level prediction using genetic programming: the importance of precipitation data and weather station location on model accuracy
Publisher: Springer Science and Business Media LLC
Date: 21-12-2020
Space use and temporal partitioning of sympatric Tasmanian devils and spotted-tailed quolls
Publisher: Wiley
Date: 18-03-2020
DOI: 10.1111/AEC.12865
Abstract: Sympatric species can minimise interspecific competition by spatial avoidance or by altering their temporal activity to reduce encounter rates. The Tasmanian devil ( Sarcophilus harrisii ), the largest carnivorous marsupial, coexists with the smaller spotted‐tailed quoll ( Dasyurus maculatus ) in Tasmania, Australia. Quolls may be susceptible to interspecific competition from devils, because they utilise similar habitats, consume similar prey species and are displaced by devils at food sources. Such competition might cause quolls to spatially or temporally avoid devils. To investigate whether spatial or temporal avoidance occurred, we deployed GPS collars on sympatric devils and quolls and conducted a camera survey at a site in northwest Tasmania where the devil population was not affected by devil facial tumour disease. GPS tracking coincided with the lactation period when devils and quolls had young in dens and continued until weaning occurred. We found little spatial segregation of home range and core area placement between devils and quolls and among devils. Quolls showed more spatial segregation within the sexes than between them. Devils had larger home ranges than quolls. Male devils had larger home ranges than females, but there was no difference in home range size between the sexes of quolls. Females of both species travelled significantly further per night than did males. There was moderate temporal partitioning between the two species: devil activity peaked after dusk and devils remained active until the early morning, while quoll activity showed distinct peaks around dusk and dawn. In conclusion, quolls did not spatially avoid devils but moderate temporal partitioning occurred. It is plausible that quolls are active at different times of the diel cycle to reduce encountering devils, but further studies are needed to resolve the cause of this temporal partitioning.
Age‐related variation in the trophic characteristics of a marsupial carnivore, the Tasmanian devil Sarcophilus harrisii
Publisher: Wiley
Date: 07-2020
DOI: 10.1002/ECE3.6513
An Australian perspective on rewilding
Publisher: Wiley
Date: 29-01-2019
DOI: 10.1111/COBI.13280
Abstract: Rewilding is increasingly recognized as a conservation tool but is often context specific, which inhibits broad application. Rewilding in Australia seeks to enhance ecosystem function and promote self-sustaining ecosystems. An absence of large-bodied native herbivores means trophic rewilding in mainland Australia has focused on the restoration of functions provided by apex predators and small mammals. Because of the pervasive influence of introduced mesopredators, predator-proof fences, and establishment of populations on predator-free islands are common rewilding approaches. This sets Australian rewilding apart from most jurisdictions and provides globally relevant insights but presents challenges to restoring function to broader landscapes. Passive rewilding is of limited utility in arid zones. Although increasing habitat extent and quality in mesic coastal areas may work, it will likely be necessary to undertake active management. Because much of Australia's population is in urban areas, rewilding efforts must include urban areas to maximize effectiveness. Thus rewilding is not synonymous with wilderness and can occur over multiple scales. Rewilding efforts must recognize human effects on other species and benefit both nature and humans. Rewilding in Australia requires development of a shared vision and strategy and proof-of-concept projects to demonstrate the benefits. The repackaging of existing conservation activities as rewilding may confuse and undermine the success of rewilding programs and should be avoided. As elsewhere, rewilding in Australia should be viewed as an important conservation tool.
Contact networks in a wild Tasmanian devil (Sarcophilus harrisii) population: Using social network analysis to reveal seasonal variability in social behaviour and its implications for transmission of devil facial tumour disease
Publisher: Wiley
Date: 11-2009
DOI: 10.1111/J.1461-0248.2009.01370.X
Abstract: The structure of the contact network between in iduals has a profound effect on the transmission of infectious disease. Using a novel technology--proximity sensing radio collars--we described the contact network in a population of Tasmanian devils. This largest surviving marsupial carnivore is threatened by a novel infectious cancer. All devils were connected in a single giant component, which would permit disease to spread throughout the network from any single infected in idual. Unlike the contact networks for many human diseases, the degree distribution was not highly aggregated. Nevertheless, the empirically derived networks differed from random networks. Contact networks differed between the mating and non-mating seasons, with more extended male-female associations in the mating season and a greater frequency of female-female associations outside the mating season. Our results suggest that there is limited potential to control the disease by targeting highly connected age or sex classes.
Quantifying extinction risk and forecasting the number of impending Australian bird and mammal extinctions
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/PC18006
Abstract: A critical step towards reducing the incidence of extinction is to identify and rank the species at highest risk, while implementing protective measures to reduce the risk of extinction to such species. Existing global processes provide a graded categorisation of extinction risk. Here we seek to extend and complement those processes to focus more narrowly on the likelihood of extinction of the most imperilled Australian birds and mammals. We considered an extension of existing IUCN and NatureServe criteria, and used expert elicitation to rank the extinction risk to the most imperilled species, assuming current management. On the basis of these assessments, and using two additional approaches, we estimated the number of extinctions likely to occur in the next 20 years. The estimates of extinction risk derived from our tighter IUCN categorisations, NatureServe assessments and expert elicitation were poorly correlated, with little agreement among methods for which species were most in danger – highlighting the importance of integrating multiple approaches when considering extinction risk. Mapped distributions of the 20 most imperilled birds reveal that most are endemic to islands or occur in southern Australia. The 20 most imperilled mammals occur mostly in northern and central Australia. While there were some differences in the forecasted number of extinctions in the next 20 years among methods, all three approaches predict further species loss. Overall, we estimate that another seven Australian mammals and 10 Australian birds will be extinct by 2038 unless management improves.
What drives the abundance of marsupial carnivores in production forest landscapes?
Publisher: Elsevier BV
Date: 02-2023
Context and trade-offs characterize real-world threat detection systems: A review and comprehensive framework to improve research practice and resolve the translational crisis
Publisher: Elsevier BV
Date: 08-2020
Retinal structure and foraging microhabitat use of the golden spiny mouse (Acomys russatus)
Publisher: Oxford University Press (OUP)
Date: 11-2001
The evolving landscape of sea-level rise science from 1990 to 2021
Publisher: Research Square Platform LLC
Date: 18-10-2022
DOI: 10.21203/RS.3.RS-2043042/V1
Abstract: As sea-level rise (SLR) accelerates due to climate change, its multidisciplinary field of science has similarly expanded, from about 50 documents in 1990 to nearly 15,000 documents from 1990 to 2021. Here, big data, bibliometric techniques are adopted to systematically analyse this growing, large-scale literature. Four main research clusters (themes) emerge: (I) geological dimensions and biogeochemical cycles, (II) impacts, risks, and adaptation, (III) physical components of sea-level change, and (IV) coastal ecosystems and habitats, with 16 associated sub-themes. This analysis provides insights into the prioritisation of research agendas, the challenges and opportunities of future integrative, global scale assessment processes (e.g., next IPCC report), and how effectively this discipline is achieving societal impact. For ex le, the relative importance of sub-themes evolves consistently with a decline in pure science analysis towards solution-focused topics associated with SLR risks such as surface elevation change, flooding, ice sheets dynamics, coastal erosion and squeeze, and engineered shorelines.
Microsatellites for the Tasmanian devil (Sarcophilus laniarius)
Publisher: Wiley
Date: 06-2003
Comparison of different geostatistical methods to estimate groundwater level at different climatic periods
Publisher: Wiley
Date: 14-06-2013
State-space modeling reveals habitat perception of a small terrestrial mammal in a fragmented landscape
Publisher: Wiley
Date: 16-08-2019
DOI: 10.1002/ECE3.5519
Density trends and demographic signals uncover the long-term impact of transmissible cancer in Tasmanian devils
Publisher: Wiley
Date: 05-02-2018
Numerical analysis of shipping water impacting a step structure
Publisher: Elsevier BV
Date: 08-2020
Telomere length is a susceptibility marker for Tasmanian devil facial tumor disease
Publisher: Springer Science and Business Media LLC
Date: 09-2020
Large‐effect loci affect survival in Tasmanian devils ( Sarcophilus harrisii ) infected with a transmissible cancer
Publisher: Wiley
Date: 05-10-2018
DOI: 10.1111/MEC.14853
A nose for death: integrating trophic and informational networks for conservation and management
Publisher: Frontiers Media SA
Date: 26-10-2016
Gene expression of Tasmanian devil facial tumors differs among host populations
Publisher: Research Square Platform LLC
Date: 10-03-2021
DOI: 10.21203/RS.3.RS-228370/V1
Abstract: Background Transmissible cancers lie at the intersection of oncology and infectious disease, two traditionally ergent fields for which gene expression studies are particularly useful for identifying the molecular basis of phenotypic variation. In oncology, transcriptomics studies, which characterize the expression of thousands of genes, have identified processes leading to heterogeneity in cancer phenotypes and in idual prognoses. More generally, transcriptomics studies of infectious diseases characterize interactions between host, pathogen, and environment to better predict population-level outcomes. Tasmanian devils have been impacted dramatically by a transmissible cancer (devil facial tumor disease DFTD) that has led to widespread population declines. Despite initial predictions of extinction, populations have persisted at low levels, due in part to heterogeneity in host responses, particularly between sexes. However, the processes underlying this variation remain unknown. Results We sequenced transcriptomes from healthy and DFTD-infected devils, as well as DFTD tumors, to characterize host responses to DFTD infection, identify differing host-tumor molecular interactions between sexes, and investigate the extent to which tumor gene expression varies among host populations. We found minimal variation in gene expression of devil lip tissues, either with respect to DFTD infection status or sex. However, 4,088 genes were differentially expressed in tumors among our s ling localities. Pathways that were up- or downregulated in DFTD tumors relative to normal tissues exhibited the same patterns of expression with greater intensity in tumors from localities that experienced DFTD for longer. No RNA sequence variants were associated with expression variation. Conclusions Expression variation among localities may underly phenotypic variation in the tumor, potentially manifesting in morphological differences that alter ratios of normal-to-tumor cells within biopsies. Phenotypic variation in tumors may arise from environmental variation or differences in host immune response that were undetectable in lip biopsies, potentially reflecting variation in host-tumor coevolutionary relationships among sites that differ in the time since DFTD arrival.
Foraging behavior and microhabitat use by spiny mice, Acomys cahirinus and A. russatus, in the presence of Blanford's fox (Vulpes cana) odor
Publisher: Springer Science and Business Media LLC
Date: 2000
Evolution and lineage dynamics of a transmissible cancer in Tasmanian devils
Publisher: Public Library of Science (PLoS)
Date: 24-11-2020
DOI: 10.1371/JOURNAL.PBIO.3000926
Abstract: Devil facial tumour 1 (DFT1) is a transmissible cancer clone endangering the Tasmanian devil. The expansion of DFT1 across Tasmania has been documented, but little is known of its evolutionary history. We analysed genomes of 648 DFT1 tumours collected throughout the disease range between 2003 and 2018. DFT1 erged early into five clades, three spreading widely and two failing to persist. One clade has replaced others at several sites, and rates of DFT1 coinfection are high. DFT1 gradually accumulates copy number variants (CNVs), and its telomere lengths are short but constant. Recurrent CNVs reveal genes under positive selection, sites of genome instability, and repeated loss of a small derived chromosome. Cultured DFT1 cell lines have increased CNV frequency and undergo highly reproducible convergent evolution. Overall, DFT1 is a remarkably stable lineage whose genome illustrates how cancer cells adapt to erse environments and persist in a parasitic niche.
The devil is in the details: Genomics of transmissible cancers in Tasmanian devils
Publisher: Public Library of Science (PLoS)
Date: 02-08-2018
Infectious disease and sickness behaviour: tumour progression affects interaction patterns and social network structure in wild Tasmanian devils
Publisher: The Royal Society
Date: 09-12-2020
Abstract: Infectious diseases, including transmissible cancers, can have a broad range of impacts on host behaviour, particularly in the latter stages of disease progression. However, the difficulty of early diagnoses makes the study of behavioural influences of disease in wild animals a challenging task. Tasmanian devils ( Sarcophilus harrisii ) are affected by a transmissible cancer, devil facial tumour disease (DFTD), in which tumours are externally visible as they progress. Using telemetry and mark–recapture datasets, we quantify the impacts of cancer progression on the behaviour of wild devils by assessing how interaction patterns within the social network of a population change with increasing tumour load. The progression of DFTD negatively influences devils' likelihood of interaction within their network. Infected devils were more active within their network late in the mating season, a pattern with repercussions for DFTD transmission. Our study provides a rare opportunity to quantify and understand the behavioural feedbacks of disease in wildlife and how they may affect transmission and population dynamics in general.
Science Under Siege
Publisher: Royal Zoological Society of New South Wales
Date: 2012
DOI: 10.7882/FS.2012.028
Landscape Management of Fire and Grazing Regimes Alters the Fine-Scale Habitat Utilisation by Feral Cats
Publisher: Public Library of Science (PLoS)
Date: 15-10-2014
Use of anthropogenic linear features by two medium-sized carnivores in reserved and agricultural landscapes
Publisher: Springer Science and Business Media LLC
Date: 14-09-2017
DOI: 10.1038/S41598-017-11454-Z
Abstract: Many carnivores are threatened by habitat loss and fragmentation. These changes create linear features and habitat edges that can facilitate foraging and/or travel. To understand the significance of anthropogenic linear features in the ecology of carnivores, fine-scaled studies are needed. We studied two medium-sized carnivores: the endangered Tasmanian devil ( Sarcophilus harrisii ) and the near threatened spotted-tailed quoll ( Dasyurus maculatus ), in a mixed landscape of conservation and agricultural land. Using GPS tracking, we investigated their use of intact habitat versus linear features such as roads, fences and the pasture/cover interface. Both species showed a positive selection for anthropogenic linear features, using the pasture/cover interface for foraging and roads for movement and foraging. Devils travelled along fence lines, while quolls showed little preference for them. Otherwise, both species foraged in forest and travelled through pasture. While devils and quolls can utilise anthropogenic linear features, we suggest that their continued survival in these habitats may depend on the intensity of other threats, e.g. persecution, and providing that sufficient intact habitat remains to sustain their ecological needs. We suggest that the management of both species and probably many other species of carnivores should focus on controlling mortality factors associated with human use of landscapes.
Groundwater as a source of dissolved organic matter to coastal waters: Insights from radon and CDOM observations in 12 shallow coastal systems
Publisher: Wiley
Date: 24-09-2019
DOI: 10.1002/LNO.11028
Immunoglubolin dynamics and cancer prevalence in Tasmanian devils (Sarcophilus harrisii)
Publisher: Springer Science and Business Media LLC
Date: 29-04-2016
DOI: 10.1038/SREP25093
Abstract: Immunoglobulins such as IgG and IgM have been shown to induce anti-tumour cytotoxic activity. In the present study we therefore explore total serum IgG and IgM expression dynamics in 23 known-aged Tasmanian devils ( Sarcophilus harrisii ) of which 9 where affected by Devil Facial Tumour Disease (DFTD). DFTD is clonally transmissible cancer that has caused massive declines in devil numbers. Our analyses revealed that IgM and IgG expression levels as well as IgM/IgG ratios decreased with increasing devil age. Neither age, sex, IgM nor IgG expression levels affected devil DFTD status in our analyses. However, devils with increased IgM relative to IgG expression levels had significantly lower DFTD prevalence. Our results therefore suggest that IgM/IgG ratios may play an important role in determining devil susceptibility to DFTD. We consequently propose that our findings warrant further studies to elucidate the underpinning(s) of devil IgM/IgG ratios and DFTD status.
The Devil's Cancer
Publisher: Springer Science and Business Media LLC
Date: 06-2011
Disease-induced decline of an apex predator drives invasive dominated states and threatens biodiversity
Publisher: Wiley
Date: 02-2016
DOI: 10.1890/15-0204.1
Abstract: Apex predators are important in protecting bio ersity through top-down influence on food webs. Their loss is linked with competitive release of invasive mesopredators and species extinctions. The Tasmanian devil (Sarcophilus harrisii) has experienced severe declines over a 15-yr period as a novel transmissible cancer has spread across its current geographic range. We surveyed the mammalian community, using hair traps, across the spatial extent of the devil's progressive population decline. We found increased activity of alien invasive species (feral cats, black rats), and reduced small and medium-sized native prey species in response to the timing of the decline. In areas of long-term devil decline, invasive species comprised a significantly larger proportion of the community. The results provide evidence that the devil plays a keystone role in Tasmania's ecosystem with their decline linked to a shift toward an invasive state and bio ersity loss in one of Australia's most intact faunal communities.
Blood Parasites in Endangered Wildlife-Trypanosomes Discovered during a Survey of Haemoprotozoa from the Tasmanian Devil
Publisher: MDPI AG
Date: 23-10-2020
Abstract: The impact of emerging infectious diseases is increasingly recognised as a major threat to wildlife. Wild populations of the endangered Tasmanian devil, Sarcophilus harrisii, are experiencing devastating losses from a novel transmissible cancer, devil facial tumour disease (DFTD) however, despite the rapid decline of this species, there is currently no information on the presence of haemoprotozoan parasites. In the present study, 95 Tasmanian devil blood s les were collected from four populations in Tasmania, Australia, which underwent molecular screening to detect four major groups of haemoprotozoa: (i) trypanosomes, (ii) piroplasms, (iii) Hepatozoon, and (iv) haemosporidia. Sequence results revealed Trypanosoma infections in 32/95 in iduals. Trypanosoma copemani was identified in 10 Tasmanian devils from three sites and a second Trypanosoma sp. was identified in 22 in iduals that were grouped within the poorly described T. cyclops clade. A single blood s le was positive for Babesia sp., which most closely matched Babesia lohae. No other blood protozoan parasite DNA was detected. This study provides the first insight into haemoprotozoa from the Tasmanian devil and the first identification of Trypanosoma and Babesia in this carnivorous marsupial.
Reintroduction of Tasmanian devils to mainland Australia can restore top-down control in ecosystems where dingoes have been extirpated
Publisher: Elsevier BV
Date: 11-2015
Reversible epigenetic down-regulation of MHC molecules by devil facial tumour disease illustrates immune escape by a contagious cancer
Publisher: Proceedings of the National Academy of Sciences
Date: 11-03-2013
Abstract: Contagious cancers that pass between in iduals as an infectious cell line are highly unusual pathogens. Devil facial tumor disease (DFTD) is one such contagious cancer that emerged 16 y ago and is driving the Tasmanian devil to extinction. As both a pathogen and an allograft, DFTD cells should be rejected by the host–immune response, yet DFTD causes 100% mortality among infected devils with no apparent rejection of tumor cells. Why DFTD cells are not rejected has been a question of considerable confusion. Here, we show that DFTD cells do not express cell surface MHC molecules in vitro or in vivo, due to down-regulation of genes essential to the antigen-processing pathway, such as β 2 -microglobulin and transporters associated with antigen processing. Loss of gene expression is not due to structural mutations, but to regulatory changes including epigenetic deacetylation of histones. Consequently, MHC class I molecules can be restored to the surface of DFTD cells in vitro by using recombinant devil IFN-γ, which is associated with up-regulation of the MHC class II transactivator, a key transcription factor with deacetylase activity. Further, expression of MHC class I molecules by DFTD cells can occur in vivo during lymphocyte infiltration. These results explain why T cells do not target DFTD cells. We propose that MHC-positive or epigenetically modified DFTD cells may provide a vaccine to DFTD. In addition, we suggest that down-regulation of MHC molecules using regulatory mechanisms allows evolvability of transmissible cancers and could affect the evolutionary trajectory of DFTD.
Intermittently Closed and Open Lakes and/or Lagoons (ICOLLs) as groundwater-dominated coastal systems: Evidence from seasonal radon observations
Publisher: Elsevier BV
Date: 04-2016
Dissolved iron exports from an estuary surrounded by coastal wetlands: Can small estuaries be a significant source of Fe to the ocean?
Publisher: Elsevier BV
Date: 11-2015
Transmission dynamics of Tasmanian devil facial tumor disease may lead to disease-induced extinction
Publisher: Wiley
Date: 12-2009
DOI: 10.1890/08-1763.1
Abstract: Most pathogens threatening to cause extinction of a host species are maintained on one or more reservoir hosts, in addition to the species that is threatened by disease. Further, most conventional host-pathogen theory assumes that transmission is related to host density, and therefore a pathogen should become extinct before its sole host. Tasmanian devil facial tumor disease is a recently emerged infectious cancer that has led to massive population declines and grave concerns for the future persistence of this largest surviving marsupial carnivore. Here we report the results of mark-recapture studies at six sites and use these data to estimate epidemiological parameters critical to both accurately assessing the risk of extinction from this disease and effectively managing this disease threat. Three sites were monitored from before or close to the time of disease arrival, and at three others disease was well established when trapping began, in one site for at least 10 years. We found no evidence for sex-specific differences in disease prevalence and little evidence of consistent seasonal variation in the force of infection. At all sites, the disease was maintained at high levels of prevalence (>50% in 2-3-year-old animals), despite causing major population declines. We also provide the first estimates of the basic reproductive rate R0 for this disease. Using a simple age-structured deterministic model, we show that our results are not consistent with transmission being proportional to the density of infected hosts but are consistent with frequency-dependent transmission. This conclusion is further supported by the observation that local disease prevalence in 2-3-year-olds still exceeds 50% at a site where population density has been reduced by up to 90% in the past 12 years. These findings lend considerable weight to concerns that this host-specific pathogen will cause the extinction of the Tasmanian devil. Our study highlights the importance of rapidly implementing monitoring programs to determine how transmission depends on host density and emphasizes the need for ongoing management strategies involving a disease-free "insurance population," along with ongoing field monitoring programs to confirm whether local population extinction occurs.
Dominant carnivore loss benefits native avian and invasive mammalian scavengers
Publisher: Cold Spring Harbor Laboratory
Date: 06-09-2021
DOI: 10.1101/2021.09.06.459188
Abstract: Scavenging by large carnivores is integral for ecosystem functioning by limiting the build-up of carrion and facilitating widespread energy flows. However, top carnivores have declined across the world, triggering trophic shifts within ecosystems. In this study, we use a natural ‘removal experiment’ of disease-driven decline and island extirpation of native mammalian (marsupial) carnivores to investigate top-down control on utilisation of experimentally placed carcasses by two mesoscavengers – the invasive feral cat and native forest raven. Ravens were the main beneficiary of carnivore loss, scavenging for five times longer in the absence of native mammalian carnivores. Cats scavenged on almost half of all carcasses in the region without dominant native carnivores. This was eight times more than in areas where other carnivores were at high densities. In the absence of native mammalian carnivores, all carcasses persisted in the environment for 3 weeks. Our results reveal the efficiency of carrion consumption by mammalian scavengers. These services are not readily replaced by less-efficient facultative scavengers. This demonstrates the significance of global carnivore conservation and supports novel management approaches, such as rewilding in areas where the natural suite of carnivores is missing.
A decade of restoring a temperate woodland: Lessons learned and future directions
Publisher: Wiley
Date: 12-2021
DOI: 10.1111/EMR.12537
Abstract: We synthesise the findings from 10 years of ecological restoration in the Midlands of Tasmania, Australia, captured in the series of 14 papers in this special issue of Ecological Management and Restoration. The papers illustrate how expertise from disciplines as erse as law, economics, social sciences, the arts, education, zoology, botany, genetics, climate modelling, agriculture, spatial sciences and fire ecology are necessary to address the complex social, ecological and financial questions that underpin restoration ecology. We highlight the complexity of the task, the multi‐disciplinary and collaborative approach needed, the importance of science to inform restoration practice and the problem of achieving functional connectivity. We also outline steps that need to be taken in the next 10 years. Together, the outcomes and recommendations from these studies provide a template for restoration in similar highly cleared and degraded agricultural landscapes affected by climate change in Australia and internationally.
Management of invasive mesopredators in the Flinders Ranges, South Australia: effectiveness and implications
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/WR19237
Abstract: Abstract ContextSignificant resources have been devoted to the control of introduced mesopredators in Australia. However, the control or removal of one pest species, such as, for ex le, the red fox (Vulpes vulpes), may inadvertently benefit other invasive species, namely feral cats (Felis catus) and rabbits (Oryctolagus cuniculus), potentially jeopardising native-species recovery. AimsTo (1) investigate the impact of a large-scale, long-term fox-baiting program on the abundance of foxes, feral cats and introduced and native prey species in the Flinders Ranges, South Australia, and (2) determine the effectiveness of a short time period of cat removal in immediately reducing feral cat abundance where foxes are absent. MethodsWe conducted an initial camera-trap survey in fox-baited and unbaited sites in the Flinders Ranges, to quantify the impact of fox baiting on the relative abundance of foxes, feral cats and their prey. We then conducted a secondary survey in sites where foxes were absent, following an intensive, but short, time period of cat removal, in which 40 cats were shot and killed. Key resultsNo foxes were detected within baited sites, but were frequently detected in unbaited sites. We found a corresponding and significant increase in several native prey species in fox-baited sites where foxes were absent. Feral cats and rabbits were also more frequently detected within baited sites, but fox baiting did not singularly predict the abundance of either species. Rather, feral cats were less abundant in open habitat where foxes were present (unbaited), and rabbits were more abundant within one predominantly open-habitat site, where foxes were absent (fox-baited). We found no effect of short-term cat removal in reducing the local abundance of feral cats. In both camera-trap surveys, feral cat detections were positively associated with rabbits. ConclusionsLong-term fox baiting was effective in fox removal and was associated with a greater abundance of native and introduced prey species in the Flinders Ranges. To continue to recover and conserve regional bio ersity, effective cat control is required. ImplicationsOur study showed fox removal has likely resulted in the local release of rabbits and an associated increase in cats. Because feral cat abundance seemingly fluctuated with rabbits, we suggest rabbit control may provide an alternative and more effective means to reduce local feral cat populations than short-term removal programs.
The evolving landscape of sea-level rise science from 1990 to 2021
Publisher: Springer Science and Business Media LLC
Date: 14-07-2023
DOI: 10.1038/S43247-023-00920-4
Abstract: As sea-level rise (SLR) accelerates due to climate change, its multidisciplinary field of science has similarly expanded, from 41 articles published in 1990 to 1475 articles published in 2021, and nearly 15,000 articles published in the Web of Science over this 32-year period. Here, big-data bibliometric techniques are adopted to systematically analyse this large literature set. Four main research clusters (themes) emerge: (I) geological dimensions and sea-level indicators, (II) impacts, risks, and adaptation, (III) physical components of sea-level change, and (IV) coastal ecosystems and habitats, with 16 associated sub-themes. This analysis provides insights into the evolution of research agendas, the challenges and opportunities for future assessments (e.g. next IPCC reports), and growing focus on adaptation. For ex le, the relative importance of sub-themes evolves consistently with a relative decline in pure science analysis towards solution-focused topics associated with SLR risks such as high-end rises, declining ecosystem services, flood hazards, and coastal erosion/squeeze.
Dietary partitioning of Australia’s two marsupial hypercarnivores, the Tasmanian devil and the spotted-tailed quoll, across their shared distributional range
Publisher: Public Library of Science (PLoS)
Date: 27-11-2017
Faecal glucocorticoid metabolite levels of intensive captive, free‐range captive and wild Tasmanian devils
Publisher: Wiley
Date: 05-06-2023
DOI: 10.1111/JZO.13072
Abstract: Captivity can alter the stress physiology and behaviour of an animal in both the short‐ and long‐term through repetitive exposure to novel stressors and, subsequently, may reduce the success of conservation efforts such as translocation and reintroduction. The Tasmanian devil ( Sarcophilus harrisii ) is threatened with extinction from a fatal facial tumour disease which has led to the establishment of an insurance meta‐population designed for future reintroductions of disease‐free devils. The meta‐population is comprised of intensive captive and free‐range captive environments however, no study has yet examined the long‐term physiological implications of captivity on devils. We used non‐invasive faecal glucocorticoid metabolite (FGM) monitoring to determine if there were any differences in adrenal activity among intensive captive, free‐range captive and wild devils. FGM levels were not age or sex dependent, and we found that all population types had similar intra‐population variability and mean FGMs. In conclusion, both types of captive environment appear to maintain stress profiles similar to wild devils.
Devil declines and catastrophic cascades: Is mesopredator release of feral cats inhibiting recovery of the eastern quoll?
Publisher: Public Library of Science (PLoS)
Date: 11-03-2015
Differing effects of productivity on home range size and population density of mammalian carnivores
Publisher: CSIRO Publishing
Date: 09-12-2021
DOI: 10.1071/WR20134
Abstract: Abstract Context Home-range size and population density characteristics are crucial information in the design of effective wildlife management, whether for conservation or control, but can vary widely among populations of the same species. Aims We investigate the influence of site productivity on home-range size and population density for Australian populations of the native, threatened spotted-tailed quoll (Dasyurus maculatus) and the alien and highly successful feral cat (Felis catus). Methods We use live trapping and fine-scale GPS tracking to determine the home-range size and population density for both species across five sites in Tasmania. Using these data, as well as published estimates for both species from across Australia, we model how these parameters change in response to productivity gradients. We also use the telemetry data to examine the energetic costs of increasing home-range size for both species. Key results For both species, decreasing site productivity correlates with lower population density, and in spotted-tailed quolls and female feral cats, it also correlates with larger home-range sizes. However, the relative magnitude of these changes is different. Feral cats show smaller increases in home-range size but larger decreases in population density relative to spotted-tailed quolls. Our results suggest that these differences may be because increases in home-range size are more costly for feral cats, demonstrated by larger increases in nightly movement for the same increase in home-range area. Conclusions We suggest that knowledge of both home-range size and population density is needed to accurately determine how species respond to habitat productivity, and inform effective management across their geographic range. Implications These results have clear management implications for ex le, in our low-rainfall sites, an adult female spotted-tailed quoll requires up to five times the amount of habitat expected on the basis of previous studies, thus dramatically increasing the costs of conservation programs for this threatened native species. Conversely, productivity-driven differences of up to four-fold in feral cat population density would influence the resources required for successful control programs of this invasive species.
Saving the Tasmanian Devil
Publisher: CSIRO Publishing
Date: 2019
Abstract: The Tasmanian devil is threatened by Devil Facial Tumour Disease (DFTD), a transmissible form of cancer that has reduced the population by over 80%. Persecution, extreme climate events, vehicle collision and habitat destruction also put pressure on this endangered species. The recovery effort to save the Tasmanian devil commenced over 15 years ago as a collaborative initiative between the Tasmanian government, the Australian government, the Zoo and Aquarium Association Australasia, and many research institutions. Saving the Tasmanian Devil documents the journey taken by partner organisations in discovering what DFTD is, the effect it has on wild devil populations, and the outcomes achieved through research and management actions. Chapters describe all aspects of devil conservation, including the captive devil populations, applied pathology, immunology and genetic research findings, adaptive management, and the importance of advocacy and partnerships. This book will provide management practitioners and conservation scientists with insight into the complexities of undertaking a program of this scale, and will also be of value to researchers, students and others interested in conservation.
Hematologic and serum biochemical reference intervals for wild Tasmanian devils (Sarcophilus harrisii)
Publisher: Wiley
Date: 27-11-2015
DOI: 10.1111/VCP.12304
Abstract: The Tasmanian devil (Sarcophilus harrisii) is a carnivorous marsupial threatened with extinction by a fatally infectious cancer known as devil facial tumor disease (DFTD). Conservation efforts including captive breeding and island translocations are underway to address this threat. The objectives of this study were to determine hematologic and serum biochemical reference intervals (RI) to aid in health assessment of Tasmanian devils, and to examine seasonal, sex, reproductive status and age variations. We collected jugular blood s les from in idual wild Tasmanian devils at 2 different locations over a 2-year period to determine hematologic and serum biochemical RI by nonparametric methods using the central 0.95 fraction. A total of 307 blood s les were collected from 187 devils. Significant age differences were found for ALP, CK, cholesterol, calcium, phosphate, albumin, globulins, albumin: globulin ratio, and glucose. Significant differences between sexes were observed for AST, creatinine, and potassium. Significant seasonal or reproductive status variation in adult males or breeding females were observed for PCV, HGB, RBC, MCHC, MCH, MCV, neutrophils and lymphocytes, fibrinogen, total plasma protein, AST, ALP, ALT, GLDH, bilirubin, urea, calcium, chloride, total protein, albumin, A:G, and glucose. Many of the differences observed between subgroups can be explained by growth requirements, reproductive demands, and seasonal effects on activity. This study has determined comprehensive RI for the Tasmanian devil, which will be used to assess animals targeted for captive breeding and translocations, or affected by DFTD.
Cathelicidin-3 Associated With Serum Extracellular Vesicles Enables Early Diagnosis of a Transmissible Cancer
Publisher: Frontiers Media SA
Date: 29-03-2022
DOI: 10.3389/FIMMU.2022.858423
Abstract: The identification of practical early diagnostic biomarkers is a cornerstone of improved prevention and treatment of cancers. Such a case is devil facial tumor disease (DFTD), a highly lethal transmissible cancer afflicting virtually an entire species, the Tasmanian devil ( Sarcophilus harrisii ). Despite a latent period that can exceed one year, to date DFTD diagnosis requires visual identification of tumor lesions. To enable earlier diagnosis, which is essential for the implementation of effective conservation strategies, we analyzed the extracellular vesicle (EV) proteome of 87 Tasmanian devil serum s les using data-independent acquisition mass spectrometry approaches. The antimicrobial peptide cathelicidin-3 (CATH3), released by innate immune cells, was enriched in serum EV s les of both devils with clinical DFTD (87.9% sensitivity and 94.1% specificity) and devils with latent infection (i.e., collected while overtly healthy, but 3-6 months before subsequent DFTD diagnosis 93.8% sensitivity and 94.1% specificity). Although high expression of antimicrobial peptides has been mostly related to inflammatory diseases, our results suggest that they can be also used as accurate cancer biomarkers, suggesting a mechanistic role in tumorous processes. This EV-based approach to biomarker discovery is directly applicable to improving understanding and diagnosis of a broad range of diseases in other species, and these findings directly enhance the capacity of conservation strategies to ensure the viability of the imperiled Tasmanian devil population.
The evolution of two transmissible cancers in Tasmanian devils
Publisher: American Association for the Advancement of Science (AAAS)
Date: 21-04-2023
Abstract: Tasmanian devils have spawned two transmissible cancer lineages, named devil facial tumor 1 (DFT1) and devil facial tumor 2 (DFT2). We investigated the genetic ersity and evolution of these clones by analyzing 78 DFT1 and 41 DFT2 genomes relative to a newly assembled, chromosome-level reference. Time-resolved phylogenetic trees reveal that DFT1 first emerged in 1986 (1982 to 1989) and DFT2 in 2011 (2009 to 2012). Subclone analysis documents transmission of heterogeneous cell populations. DFT2 has faster mutation rates than DFT1 across all variant classes, including substitutions, indels, rearrangements, transposable element insertions, and copy number alterations, and we identify a hypermutated DFT1 lineage with defective DNA mismatch repair. Several loci show plausible evidence of positive selection in DFT1 or DFT2, including loss of chromosome Y and inactivation of MGA , but none are common to both cancers. This study reveals the parallel long-term evolution of two transmissible cancers inhabiting a common niche in Tasmanian devils.
Diet overlap and relative abundance of sympatric dasyurid carnivores: A hypothesis of competition
Publisher: Wiley
Date: 05-1998
Research supporting restoration aiming to make a fragmented landscape ‘functional’ for native wildlife
Publisher: Wiley
Date: 12-2021
DOI: 10.1111/EMR.12504
Abstract: Temperate woodlands are amongst the most threatened ecosystems in Australia because the land on which they occur is highly suited to agriculture. Two hundred years of habitat loss and fragmentation in the Midlands agricultural region in Tasmania have led to widespread declines in native vertebrates and landscapes with populations of predators including feral Cat ( Felis catus ) and the native‐invasive Noisy Miner ( Manorina melanocephala ). Ecologists at the University of Tasmania co‐designed mechanistic animal‐centric research on mammals and birds in the Midlands to inform vegetation restoration carried out by Greening Australia that would support the recovery of wildlife species. We used species‐appropriate technologies to assess the decisions made by in idual animals to find food and shelter and to disperse across this fragmented landscape, and linked these, together with patterns of occupancy, across multiple spatial and temporal scales. We focussed on a native (Spotted‐tailed Quoll, Dasyurus maculatus ) and an invasive (feral Cat, Felis catus ) carnivore, a woodland‐specialist herbivore (Eastern Bettong, Bettongia gaimardi ) and woodland birds including the native‐invasive Noisy Miner. Our results, which show intense predatory and competitive pressure of cats and populations of Noisy Miner on native fauna, highlight how grounding restoration in the context of ecological interactions is essential to success in managing the impacts of invasive species in restored landscapes. Successful restoration will require innovative approaches in plantings and field experimentation with artificial refuges, to reduce habitat suitability for the Noisy Miner and cats and provide refuges for native mammals and birds to live in the landscape where cats also occur. Our results emphasise the significance of structural complexity of restoration plantings for supporting the recolonisation and persistence of native fauna. At large landscape‐scale, we demonstrate the importance of retaining small habitat elements, including ancient paddock trees, pivot irrigation corners and small, degraded remnants, in facilitating occupancy and dispersal and, therefore, persistence of wild animals across this agricultural region.
Limited top–down effects of feral cats on rodent dynamics in a seabird colony
Publisher: Springer Science and Business Media LLC
Date: 30-08-2023
DOI: 10.1007/S10530-023-03152-X
Abstract: Control of invasive predators is a priority to protect island bio ersity. Understanding the responses of other species in multi-species invaded food webs is important to avoid unintended consequences. We use an intensive 2-year cat-trapping program in the vicinity of seabird colonies on Bruny Island, Tasmania, to investigate its effectiveness in reducing feral cat density and whether cat control influenced the behaviour and abundance of native and invasive mammal species. Cat density before control was extremely high around this seasonally rich food resource, much higher than on mainlands. Cat density was reduced 5.4-fold by control showing that trapping is effective in reducing cat density in this focussed landscape context. We found no direct effect of cat reduction on the abundance or behaviour of native or invasive mammalian prey species. Recruitment of invasive black rats and native sw rats increased on the seabird colonies after the shearwater breeding season, and cats responded by increasing their presence on the colonies relative to surrounding areas. This suggests cascading bottom-up effects from a lagged productivity pulse provided by breeding seabirds which would require nutrient s ling to confirm. Our results highlight the complexity of subsequent effects of an invasive predator control on the broader ecosystem.
Temporal partitioning of activity: rising and falling top-predator abundance triggers community-wide shifts in diel activity
Publisher: Wiley
Date: 27-09-2019
DOI: 10.1111/ECOG.04485
Trophic Cascades Following the Disease-Induced Decline of an Apex Predator, the Tasmanian Devil
Publisher: Wiley
Date: 11-09-2014
DOI: 10.1111/COBI.12152
Abstract: As apex predators disappear worldwide, there is escalating evidence of their importance in maintaining the integrity and ersity of the ecosystems they inhabit. The largest extant marsupial carnivore, the Tasmanian devil ( Sarcophilus harrisii ) is threatened with extinction from a transmissible cancer, devil facial tumor disease (DFTD). The disease, first observed in 1996, has led to apparent population declines in excess of 95% in some areas and has spread to more than 80% of their range. We analyzed a long‐term Tasmania‐wide data set derived from wildlife spotlighting surveys to assess the effects of DFTD‐induced devil decline on populations of other mammals and to examine the relative strength of top–down and bottom–up control of mesopredators between 2 regions with different environmental conditions. Collection of the data began years before DFTD was first observed. A decrease in devil populations was immediate across diseased regions following DFTD arrival, and there has been no indication of population recovery. Feral cats ( Felis catus ) increased in areas where the disease was present the longest, and feral cat occurrence was significantly and negatively associated with devils. The smallest mesopredator, the eastern quoll ( Dasyurus viverrinus ), declined rapidly following DFTD arrival. This result suggests the species was indirectly protected by devils through the suppression of larger predators. Rainfall deficiency was also a significant predictor of their decline. Environmental variables determined the relative importance of top–down control in the population regulation of mesopredators. In landscapes of low rainfall and relatively higher proportions of agriculture and human settlement, top–down forces were d ened and bottom–up forces had the most effect on mesopredators. For herbivore prey species, there was evidence of population differences after DFTD arrival, but undetected environmental factors had greater effects. The unique opportunity to assess population changes over extensive temporal and spatial scales following apex predator loss further demonstrated their role in structuring ecosystems and of productivity in determining the strength of top–down control . Cascadas Tróficas Después de la Declinación Inducida por Enfermedad de un Depredador Apical, el Demonio de Tasmania
Spontaneous Tumor Regression in Tasmanian Devils Associated with RASL11A Activation
Publisher: Oxford University Press (OUP)
Date: 08-2020
DOI: 10.1534/GENETICS.120.303428
Abstract: Spontaneous cancer regression in humans is uncommon, but understanding the mechanisms is key for advancing treatment. Using Devil Facial Tumor Disease as a model, Margres et al. employed comparative....
Changes in spatial organization following an acute epizootic: Tasmanian devils and their transmissible cancer
Publisher: Elsevier BV
Date: 06-2020
Top carnivore decline has cascading effects on scavengers and carrion persistence
Publisher: The Royal Society
Date: 28-11-2018
Abstract: Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii) , has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competition for carrion, whereas consumption by the invasive mesopredator, the feral cat ( Felis catus ), was better predicted by the landscape-level abundance of devils, suggesting a relaxed landscape of fear where devils are suppressed. Reduced discovery of carcasses by devils was balanced by the increased discovery by mesopredators. Nonetheless, carcasses persisted approximately 2.6-fold longer where devils have declined, highlighting their importance for rapid carrion removal. The major beneficiary of increased carrion availability was the forest raven ( Corvus tasmanicus ). Population trends of ravens increased 2.2-fold from 1998 to 2017, the period of devil decline, but this increase occurred Tasmania-wide, making the cause unclear. This case study provides a little-studied potential mechanism for mesopredator release, with broad relevance to the vast areas of the world that have suffered carnivore declines.
Emerging infectious diseases of wildlife: a critical perspective
Publisher: Elsevier BV
Date: 04-2015
Abstract: We review the literature to distinguish reports of vertebrate wildlife disease emergence with sufficient evidence, enabling a robust assessment of emergence drivers. For potentially emerging agents that cannot be confirmed, sufficient data on prior absence (or a prior difference in disease dynamics) are frequently lacking. Improved surveillance, particularly for neglected host taxa, geographical regions and infectious agents, would enable more effective management should emergence occur. Exposure to domestic sources of infection and human-assisted exposure to wild sources were identified as the two main drivers of emergence across host taxa the domestic source was primary for fish while the wild source was primary for other taxa. There was generally insufficient evidence for major roles of other hypothesized drivers of emergence.
Faecal glucocorticoid metabolite levels of intensive captive, free-range captive, and wild Tasmanian devils
Publisher: Cold Spring Harbor Laboratory
Date: 11-01-2023
DOI: 10.1101/2023.01.11.523346
Abstract: Captivity can alter the stress physiology and behaviour of an animal in both the short- and long-term through repetitive exposure to novel stressors and, subsequently, may reduce the success of conservation efforts such as translocation and reintroduction. The Tasmanian devil ( Sarcophilus harrisii ) is threatened with extinction from a fatal facial tumour disease which has led to the establishment of an insurance meta-population designed for future reintroductions of disease-free devils. The meta-population is comprised of intensive captive and free-range captive environments however, no study has yet examined the long-term physiological implications of captivity on devils. We used non-invasive faecal glucocorticoid metabolite (FGM) monitoring to determine if there were any differences in adrenal activity between intensive captive, free-range captive, and wild devils. FGMs were not age- or sexdependent, and we found that all population-types had similar intra-population variability and mean FGMs. In conclusion, both types of captive environment maintain stress profiles similar to wild devils.
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