Suchergebnisse

Invasive alien species are responsible for considerable biodiversity loss and environmental damage. Timely detection of new incursions is critical in preventing novel populations establishing. Citizen reports currently account for the majority of alien species detections, arising from the massive observation effort that the physical and digital 'eyes and ears' of citizens provide, in combination with crowd-sourced species identification. Because the reporting of alien species sightings is generally not mandatory, there is interest in whether mining social media data via image recognition and/or natural language processing can improve on existing passive citizen surveillance in a cost-effective manner. Here, we illustrate, using examples from Australia, how citizen surveillance for most vertebrate groups appears to currently be effective using existing voluntary reporting mechanisms. Where citizen surveillance is currently ineffective, for reasons of inadequate sampling, data mining of social media feeds will be similarly affected. We argue that mining citizens' social media data for evidence of invasive alien species needs to demonstrate not only that it will be an improvement on the business as usual case, but also that any gains achieved cannot be achieved by alternative approaches. We highlight the potential role of education in increasing the surveillance effectiveness of citizens for detecting and reporting sightings of alien species. Should data mining of social media platforms be pursued, we note that the scale of the task in terms of the potential number of exotic vertebrate species to be classified is very large. The expected number of false positive classifications would present a considerable workload to process, possibly undermining the efficiency rationale for the use of data mining. Hence, prioritisation is needed, and we illustrate how the number of species to be classified can be reduced considerably. If we are to deploy data mining and analysis of social media data to help with detecting introductions of invasive alien species, we need to conduct it in a manner where it adds value and is trusted.

Context
Biological invasions are a profound contribution to human-induced environmental change. Although intentional introductions of vertebrate species have largely declined, global transport and communication networks continue to increase. As a consequence, more goods are being traded and the type of species being transported has changed, as well as the associated risks.


Aims
To analyse the frequency, and provide risk assessments, for exotic vertebrate species detected by border and post-border Australian biosecurity agencies in the past decade (1999–2010).


Methods
We collated detection records by emailing or telephoning representatives from agencies responsible for implementing Australian biosecurity. We calculated the risk of successful establishment (low, moderate, serious, extreme) for 137 identified vertebrate species not currently established in Australia. Generalised linear models were constructed to test whether the frequency of increasing risk of establishment was associated with either differences between vertebrate classes and/or different detection categories.


Key results
The majority of species detected were reported from illegal keeping. Individual species risk assessments revealed that reptiles were more likely to be of greater risk for future establishment than were birds, mammals or amphibians. Controlling for taxonomy, high-risk species were not involved in larger (i.e. number of individuals) incidents than were lower-risk species. Across years, the number of novel exotic vertebrate species detected 'at large' in Australia has significantly increased.


Conclusions
Several of the species detected by biosecurity agencies have attributes that give them the potential to become pests in Australia. Preventing incursions is by far the most cost-effective way to prevent future pest damage.


Implications
It is clear that a nationally coordinated framework for data collection and data sharing among agencies is urgently required. We present a minimum framework for the future collection of inter-agency data, necessary to assess and monitor the ongoing risk of vertebrate pest incursions in Australia.

Abstract Context The koala (Phascolarctos cinereus) sometimes occurs as an overabundant folivore in south-eastern Australia, where high-density populations have caused defoliation of preferred food trees, threatening habitat. Kangaroo Island, South Australia and Budj Bim National Park, Victoria, are two regions where such eruptive population dynamics have arisen. One way of mitigating their damage is through management via fertility control. Aims This paper examines the outcomes of fertility control (surgical sterilisation and treatment with levonorgestrel implants) on breeding dynamics at the population level, using data obtained from two separate koala management programs conducted by State Government wildlife agencies, South Australia Department for Environment and Water and Parks Victoria. Methods The relationships between female body condition, reproductive status, fertility control, age and population density were examined using linear mixed effects models. Population density (koalas/ha) was estimated using annual census data and modelled in a Bayesian framework. Key results Body condition was a key influence on breeding success in female koalas, with sexual maturity being defined by both age and body condition, whereas the effect of reproductive experience was minimal. It is likely that reduced densities have led to decreased intraspecific competition for food resources and territory, leading to increased breeding success at one management site (BBNP) and by allowing females to begin breeding at a lower overall body condition. The reduction in densities to sustainable levels at both management sites, despite differing fertility-control methods, supports the use of the less invasive and more cost-effective levonorgestrel implants as the preferred fertility-control method. Conclusions In addition to contraceptive effects, broad-scale fertility control may have resulted in a compensatory higher breeding success in the untreated population, possibly in response to decreasing densities, increased resource availability or behavioural responses to population management. Implications Although compensatory breeding mechanisms can reduce the effectiveness of fertility control at the population level, ongoing fertility-control management can still be successful at reducing overabundant koala populations to sustainable levels with significant long-term commitment, provided that annual control targets are continuously met.

Context Wildlife trade is a prominent pathway for invasive species introductions into novel environments. Deliberate or accidental release of exotic pets can result in the establishment of alien populations, with damaging impacts for native species and environmental assets. This process is well documented for reptiles globally and is of considerable biosecurity concern in Australia. Boa constrictor is one species at high risk of establishment in Australia, and has insufficient biosecurity detection and post-border control capacity. Aims We aimed to develop rapid DNA-based presumptive testing capacity for detecting B. constrictor, with appropriate sensitivity and specificity to operate in a trace DNA biosecurity context. Methods Loop Mediated Isothermal Amplification (LAMP) is an emerging biosecurity tool that provides highly specific, sensitive, low-resource methods for detection of trace DNA in the absence of physical evidence. We developed colourimetric and fluorescent LAMP assays targeting the mitochondrial DNA control region of B. constrictor. We tested and validated these assays against synthetic DNA fragments, as well as DNA extracted from: (1) vouchered museum B. constrictor tissue; (2) shed B. constrictor skin samples; (3) a range of non-target species to test specificity; and (4) trace DNA recovered from glass tanks post B. constrictor presence. Key results We successfully detected synthetic target DNA down to 1 fg and genomic B. constrictor DNA from tissue and shed skins down to <10 pg in under 30 minutes with our fluorescence-based LAMP assay. Additionally, we were able to detect B. constrictor trace DNA following 24 h of presence utilising a traditional laboratory-based DNA extraction method (approximately 180 min) and a rapid lysis step (approximately 8 min). Conclusions Both colourimetric and fluorescent assays show promise for the specific detection of B. constrictor in biosecurity contexts, including post-border enforcement and compliance checks in the domestic illicit wildlife trade. Implications Our findings greatly strengthen the ongoing development of biosecurity tools for trace DNA detection of commonly traded and trafficked species (i.e. reptiles) in wildlife enforcement contexts, advancing both preparedness and surveillance.

Abstract ContextAustralia has a high diversity of endemic vertebrate fauna. Yet, transnational human activities continue to increase the rate of transportation, introduction and establishment of new alien vertebrates in Australia, to the detriment of environmental and socioeconomic services. Eradication of invasive vertebrates is often costly and without guarantee of success; therefore, methods for detecting, intercepting and preventing the transport of alien species earlier in the invasion pathway provide substantial benefit. AimTo anticipate emergent threats to Australian biosecurity posed by the transport and introduction of new alien vertebrates over time. MethodsWe collated vertebrate interception data from various mainland Australian State, Territory and Commonwealth government reporting agencies, including data from a previously published study, at both pre-border and post-border stages from 1999 to 2016. Using generalised linear and generalised additive modelling, we predicted trends in interception frequency using predictors such as vertebrate taxa, detection category and alien status. Key resultsInterception frequency increased over time for all vertebrate classes, for pre-border stowaways and for post-border captive and at-large interceptions, with no saturation in the accumulation of new species over time. Five species were responsible for almost half of all incidents, of which red-eared sliders (Trachemys scripta elegans), boa constrictors (Boa constrictor) and corn snakes (Pantherophis guttatus) are prominent in Australia's illegal alien pet trade. Rose-ringed parakeets (Psittacula krameri) are prominent in the legal alien cage-bird trade, which remains poorly regulated. Asian common toads (Duttaphrynus melanostictus) were frequently detected as stowaways, and most stowaway incidents originated from Southeast Asia, particularly Indonesia, via shipping. Data deficiency for pre-border incidents increased rapidly in 2015 and 2016. ConclusionsAustralia is subject to a persistent and increasing risk of alien vertebrate introductions and incursions over time, owing partly to emergent trends in the alien pet trade as well as increased global trade and tourism. ImplicationsThe future of Australia's biosecurity remains dependent on stringent border security to prevent the arrival of novel species, but our findings also highlight the importance of ongoing management and control of high-risk species already present, often illegally, within Australia.

Objectives: To assess the risk of Ebola importation to Australia during the first six months of 2015, based upon the current outbreak in West Africa. Methodology: We assessed the risk under two distinct scenarios: (i) assuming that significant numbers of cases of Ebola remain confined to Guinea, Liberia and Sierra Leone, and using historic passenger arrival data into Australia; and, (ii) assuming potential secondary spread based upon international flight data. A model appropriate to each scenario is developed, and parameterised using passenger arrival card or international flight data, and World Health Organisation case data from West Africa. These models were constructed based on WHO Ebola outbreak data as at 17 October 2014 and 3 December 2014. An assessment of the risk under each scenario is reported. On 27 October 2014 the Australian Government announced a policy change, that visas from affected countries would be refused/cancelled, and the predicted effect of this policy change is reported. Results: The current probability of at least one case entering Australia by 1 July 2015, having travelled directly from West Africa with historic passenger arrival rates into Australia, is 0.34. Under the new Australian Government policy of restricting visas from affected countries (as of 27 October 2014), the probability of at least one case entering Australia by 1 July 2015 is reduced to 0.16. The probability of at least one case entering Australia by 1 July 2015 via an outbreak from a secondary source country is approximately 0.12. Conclusions: Our models suggest that if the transmission of Ebola remains unchanged, it is possible that a case will enter Australia within the first six months of 2015, either directly from West Africa (even when current visa restrictions are considered), or via secondary outbreaks elsewhere. Government and medical authorities should be prepared to respond to this eventuality. Control measures within West Africa over recent months have contributed to a reduction in projected risk of a case ...

It has been previously suggested that the characteristics that are driving the taxonomic homogenisation of the global avifauna, through the extinction of native bird species and the establishment of exotic bird species, are opposite sides of the same coin. One of the most important tools that conservation biologists and wildlife managers have to ameliorate the extinction of a species is to reintroduce populations to stronghold areas from which they have been extirpated or were not previously common. In this paper, we address the question of what the study of exotic bird introductions can tell us to inform the translocation of native species. We review the relative importance of the five factors that have been suggested significantly to influence the successful establishment of non-native species: introduction effort, environmental matching, species' interactions, species' life histories, and phylogenetic relatedness. Current evidence suggests that introduction effort will be an important determinant of release, but how many individuals need to be released, and in how many separate release events, is contingent on characteristics of species and environment. The importance of climate matching for introduction success suggests that the success of translocations will depend greatly on the study and amelioration of the problem that caused the initial population decline. This is most problematic in situations where the decline is associated with human-induced climate change. Migratory and sexually selected species may be harder to re-establish, but related species may differ substantially in their likelihood of success. We suggest that further insights into the reintroduction process may be gained particularly by studying species that are experiencing a threat in their native range but which are also being widely released as exotics outside of this range.

Globalisation of the live pet trade facilitates major pathways for the transport and introduction of invasive alien species across longer distances and at higher frequencies than previously possible. Moreover, the unsustainable trade of species is a major driver for the over-exploitation of wild populations. Australia minimises the biosecurity and conservation risk of the international pet trade by implementing highly stringent regulations on the live import and keeping of alien pets beyond its international CITES obligations. However, the public desire to possess prohibited alien pets has never been quantified and represents a number of species that could be acquired illegally or legally under different future legislative conditions. As such, highly desirable species represent an ongoing conservation threat and biosecurity risk via the pet-release invasion pathway. We aimed to characterise the Australian desire for illegal alien pets and investigate potential sources of external information that can be utilised to predict future desire. Using public live import enquiry records from the Australian Commonwealth Department of Agriculture, Water and the Environment as a proxy for alien pet desire, we tested for differences in the proportion of species with threatened listings and records of invasions, after accounting for taxonomy. Additionally, we used a United States of America (U.S.) live imports dataset to infer pet demand in another Western market with less stringent regulations and determined whether species highly desired in Australia had higher U.S. trade demand than would be expected by chance. The Australian public desire for alien pets is heavily and significantly biased towards species threatened with extinction, species popular in the U.S. trade and species with a history of successful invasions. Not only does this indicate the potential impacts of pet desire on invasion risk and the conservation of threatened species, but we also highlight the potential role of the U.S. trade as an effective predictor ...

AbstractUnderstanding the risk of biological invasions associated with particular transport pathways and source regions is critical for implementing effective biosecurity management. This may require both a model for physical connectedness between regions, and a measure of environmental similarity, so as to quantify the potential for a species to be transported from a given region and to survive at a destination region. We present an analysis of integrated biosecurity risk into Australia, based on flights and shipping data from each global geopolitical region, and an adaptation of the "range bagging" method to determine environmental matching between regions. Here, we describe global patterns of environmental matching and highlight those regions with many physical connections. We classify patterns of global invasion risk (high to low) into Australian states and territories. We validate our analysis by comparison with global presence data for 844 phytophagous insect pest species, and produce a list of high‐risk species not previously known to be present in Australia. We determined that, of the insect pest species used for validation, the species most likely to be present in Australia were those also present in geopolitical regions with high transport connectivity to Australia, and those regions that were geographically close, and had similar environments.

We critically evaluated population-monitoring programs for three endangered species of Australian honeyeater: the helmeted honeyeater, Lichenostomus melanops cassidix, the black-eared miner, Manorina melanotis, and the regent honeyeater, Xanthomyza phrygia (Meliphagidae). Our results challenge the common assumption that meaningful monitoring is possible in all species within the five-year lifetime of recovery plans. We found that the precision achievable from monitoring programs not only depends on the monitoring technique applied but also on the species' biology. Relevant life-history attributes include a species' pattern of movement, its home-range size and its distribution. How well understood and predictable these attributes are will also influence monitoring precision. Our results highlight the large degree of variability in precision among monitoring programs and the value of applying power analysis before continuing longer-term studies. They also suggest that managers and funding agencies should be mindful that more easily monitored species should not receive preferential treatment over species that prove more difficult to monitor.

European Union's Horizon 2020, Grant/Award Number: 726176; French ANR, Grant/Award Numbers: ANR‐10‐LABX‐41, ANR‐11‐IDEX‐002‐02; French ꁆMidi‐Pyrénées Region, Grant/Award Number: CNRS 121090; ꁆEuropean Research Council, Grant/Award Number: 726176 ; Peer reviewed ; Publisher PDF

Abstract ContextPseudogymnoascus destructans is the fungus responsible for white-nose syndrome (WNS), which has killed millions of hibernating bats in North America, but also occurs in bats in Europe and China without causing large-scale population effects. This is likely to be due to differences in species susceptibility and behaviour, and environmental factors, such as temperature and humidity. Pseudogymnoascus destructans is currently believed to be absent from Australia. AimsTo ascertain the level of risk that white-nose syndrome poses for Australian bats. Methods This risk analysis examines the likelihood that P. destructans enters Australia, the likelihood of the fungus coming in contact with native bats on successful entry, and the potential consequences should this occur. Key results This risk assessment concluded that it is very likely to almost certain that P. destructans will enter Australia, and it is likely that bats will be exposed to the fungus over the next 10 years. Eight cave-dwelling bat species from southern Australia are the ones most likely to be affected. ConclusionsThe risk was assessed as medium for the critically endangered southern bent-winged bat (Miniopterus orianae bassanii), because any increase in mortality could affect its long-term survival. The risk to other species was deemed to range from low to very low, owing to their wider distribution, which extends beyond the P. destructans risk zone. Implications Although Australia's milder climate may preclude the large mortality events seen in North America, the fungus could still significantly affect Australian bat populations, particularly bent-winged bats. Active surveillance is required to confirm Australia's continuing WNS-free status, and to detect the presence of P. destructans should it enter the country. Although White-nose Syndrome Response Guidelines have been developed by Wildlife Health Australia to assist response agencies in the event of an incursion of WNS into bats in Australia, these guidelines would be strengthened by further research to characterise Australian cave temperatures and hibernating bat biology, such as length of torpor bouts and movement over winter. Risk-mitigation strategies should focus on education programs that target cavers, show-cave managers and tourists, particularly those who have visited regions where WNS is known to occur.

There are many hypotheses describing the interactions involved in biological invasions, but it is largely unknown whether they are backed up by empirical evidence. This book fills that gap by assessing research hypotheses and applying it to a number of invasion hypotheses, using the hierarchy-of-hypotheses (HoH) approach.

The legacy of deliberate and accidental introductions of invasive alien species to Australia has had a hefty economic toll, yet quantifying the magnitude of the costs associated with direct loss and damage, as well as for management interventions, remains elusive. This is because the reliability of cost estimates and under-sampling have not been determined. We provide the first detailed analysis of the reported costs associated with invasive species to the Australian economy since the 1960s, based on the recently published InvaCost database and supplementary information, for a total of 2078 unique cost entries. Since the 1960s, Australia has spent or incurred losses totalling at least US$298.58 billion (2017 value) or AU$389.59 billion (2017 average exchange rate) from invasive species. However, this is an underestimate given that costs rise as the number of estimates increases following a power law. There was an average 1.8–6.3-fold increase in the total costs per decade since the 1970s to the present, producing estimated costs of US$6.09–57.91 billion year-1 (all costs combined) or US$225.31 million–6.84 billion year-1 (observed, highly reliable costs only). Costs arising from plant species were the highest among kingdoms (US$151.68 billion), although most of the costs were not attributable to single species. Of the identified weedy species, the costliest were annual ryegrass (Lolium rigidum), parthenium (Parthenium hysterophorus) and ragwort (Senecio jacobaea). The four costliest classes were mammals (US$48.63 billion), insects (US$11.95 billion), eudicots (US$4.10 billion) and monocots (US$1.92 billion). The three costliest species were all animals – cats (Felis catus), rabbits (Oryctolagus cuniculus) and red imported fire ants (Solenopsis invicta). Each State/Territory had a different suite of major costs by species, but with most (3–62%) costs derived from one to three species per political unit. Most (61%) of the reported costs applied to multiple environments and 73% of the total pertained to direct damage or loss compared to management costs only, with both of these findings reflecting the availability of data. Rising incursions of invasive species will continue to have substantial costs for the Australian economy, but with better investment, standardised assessments and reporting and coordinated interventions (including eradications), some of these costs could be substantially reduced.