The viability of a metamorph anuran can be influenced by its body size and the time it has taken to complete larval development. In a laboratory experiment, we show that the presence of tadpoles of the invasive Cane Toad Rhinella marina causes tadpoles of a native frog (Marbled Frog Limnodynastes convexiusculus ) to metamorphose later and at smaller sizes. These effects may render frog metamorphs more vulnerable to desiccation and predation, but render them less vulnerable to Cane Toads. Marbled Frogs prey upon other anurans, including the highly toxic Cane Toad metamorphs. Small, late-emerging metamorph frogs are unlikely to encounter metamorph toads small enough to ingest; and hence, are less likely to be fatally poisoned by consuming the toxic invader. Developing in the presence of larval Cane Toads thus increases the native taxon's ability to survive the presence of toads postmetamorphosis. Predicting the ecological impacts of an invasive species on native taxa with biphasic life histories (such as most anurans) thus requires information on interactions in both aquatic and terrestrial environments. The expression of phenotypic plasticity in one phase may influence fitness in a subsequent phase, in complex and non-intuitive ways.

ABSTRACT The viral biocontrol agents Myxoma virus (MYXV) and Rabbit Haemorrhagic Disease Virus (RHDV1), released in 1950 and 1996 respectively, are the only control tools to have resulted in significant and lasting landscape-scale suppression of rabbit populations in Australia. Multiple conservation benefits and significant economic savings have resulted from the long-term and widespread reductions in rabbit numbers and impacts. In an effort to ‘boost’ rabbit biocontrol, an additional variant of RHDV1 ('K5') was recently released nationwide to counteract the decreasing effectiveness of both RHDV1 and MYXV that results from the evolutionary ‘arms race’ between viruses and their hosts. Two years prior to the K5 release, an exotic RHDV strain (RHDV2) appeared in Australia. The commercially available vaccine used to protect pet and farmed rabbits against the officially released K5 was ineffective against the exotic RHDV2, resulting in numerous deaths of domestic rabbits. This created substantial confusion about which strain was released as a biocontrol tool, as well as renewed concerns amongst pet rabbit owners and rabbit farmers about the use of viruses as lethal rabbit control tools in general. Ongoing effective control of wild rabbits in Australia is absolutely essential to protect the substantial conservation gains made by the long-term suppression of rabbit numbers over the past decades, and there is currently no alternative population control tool to achieve this at the required landscape scale. Vaccine formulations need updating to protect non-target farmed and pet rabbits from circulating field variants, including RHDV2, and to increase public acceptance for the ongoing use of viral biocontrol for feral rabbit populations.

ABSTRACT The invasive Red-eared Slider Trachemys scripta elegans has spread extensively, forming naturalised populations on all continents except Antarctica. Ranked among the 100 worst invasive species, there are biosecurity concerns that native turtles become outcompeted and displaced, as well as other speculative impacts. The actual ecological impacts in Australia have not been properly studied, however impacts shown in other countries are concerning. Incursions have presented in New South Wales, Queensland, Victoria, Western Australia and the Australian Capital Territory. A number of sightings have been reported from southern Sydney, including six sites where more than one slider has persisted. The incursions at Yeramba Lagoon in the Georges River National Park and the Centennial Parklands have been the most documented, whereas incursions in the Lime Kiln Bay Wetland, Rockdale Wetlands Corridor and Audley in the Royal National Park appear to have occurred recently. To date, breeding in southern Sydney has only been confirmed at Yeramba Lagoon. A range of removal techniques have been successfully applied to eradicate isolated incursions in Brisbane and Melbourne. However, these options are difficult to implement in southern Sydney sites where incursions occur in high visitation public lands.

ABSTRACT In conservation, consistent and extensive under-funding has necessitated creative thinking to address conservation issues on a low budget, and innovations are burgeoning as a result. One example is the use of dogs that, thanks to their heightened olfactory abilities and bond with humans, are trained to detect odours of interest to conservationists. Conservation dogs have proven to repeatedly outperform alternative survey methods in terms of accuracy, efficiency and/or cost. They have now been used for the detection of endangered and invasive species, fauna and flora, direct and indirect (e.g. scat) targets, on land and at sea, across every continent and most taxa from fire ants to whales. Here, we emphasise the versatility of detection dogs through their multiple uses applied to one species, the koala Phascolarctos cinereus . We selected, trained, tested and deployed five dogs; two for koala habitat (koala scats), one for genetic sampling (fresh scats only), one for the koala itself and one for koala disease ( Chlamydia spp. ) detection. Dogs enabled both large-scale and fine-scale survey design, with 2370 surveys performed, and 1479 genetic samples collected to date. Detection dogs are subject to similar (although sometimes much lower) limitations in terms of survey biases (e.g. individual or environmental conditions) and, importantly, detection dog/handler teams need to be tested regularly for accuracy. Nonetheless, detection dogs can, and are, helping researchers and land managers to collect more robust datasets and better inform conservation decisions. Alliances with unexpected partners in conservation (such as with police forces), citizen science, and timeshare use of dogs might improve the democratisation of their use and enable conservation detection dogs to fulfil their astonishing potential.

ABSTRACT Freshwater turtle populations are globally threatened by many factors. Complicating matters, their longevity requires long-term monitoring on the scale of decades to assess changes in population size, yet few long-term studies exist. Documenting population estimates and trends is essential for identifying and conserving imperilled populations, however, the impacts of many current threats may render populations endangered well before declines become apparent. By that stage, population recovery may not be possible, thus assessing population level impacts of potential threats may provide a direct measure of risks of population extinction. Australian turtles face major threats of mortality from invasive species, vehicles, disease and declining water quality. Even Australia's most abundant and widespread species has declined by up to 91% in some populations. Here I use population models to assess the impacts of threats to multiple life history stages of an Australia turtle. This study clearly demonstrates that Chelodina longicollis , Australia's most widespread turtle (1) is resilient to high levels of nest predation for sustained periods, (2) requires only periodic levels of reduced nest predation and pulse recruitment to maintain population viability and (3) low levels of adult mortality can drive populations to extinction. Turtle populations require pulse recruitment (i.e. nest predation rates declining to <35% every ten years) and monitoring of nest predation rates for 5–6 years to determine whether nest predation level profiles are extreme. However, if terrestrial mortality of adult turtles occurs, then the risk of extinction is high regardless of nest predation levels. Monitoring protocols to assess nest predation and adult mortality rates are not widely developed for freshwater turtles and here I develop a management plan that employs Citizen Science and standardised on-ground protocols to assess levels of threats at the population level. Standardised protocols and involvement of the public and community groups creates a network for broad-scale assessment and management of a species. Although threats can be identified and easily quantified and long-term data has demonstrated the extent of the decline of freshwater turtle populations in southern Australia, solutions to minimise risks of extinction need to be developed and fast-tracked before turtles throughout Australia become critically endangered.

Our aim in this study is to provide the first ever quantitative, historical and map–based information of what fauna has been studied and recorded both outside and inside the protected areas of New South Wales (NSW), which are principally National Parks and Nature Reserves. Our objective was to consider the value of National Parks and Nature Reserves for fauna research and biodiversity conservation, and gauge the extent and limits of our knowledge of the fauna of NSW. We compared the increase in the area of parks and reserves in NSW with the expansion of the fauna records in the Office of Environment and Heritage (OEH) Atlas of NSW Wildlife, and analysed the use of Scientific Licences issued by OEH for fauna research for 3.5 years to mid–2014. We found that the distribution and the number of Scientific Licences within protected areas show a heavy bias to the eastern strip of the State, with a greater clustering for the area around Sydney and the north coast, but it is evident that researchers make considerable use of protected areas. The 6,070,769 Atlas fauna records were divided by tenure type: National Parks held 1,118,204 records (21.4 records/km 2 ), while Nature Reserves held 386,755 records (40.6 records/km 2 ). The off–park records total was 4,407,486 representing 72.6% of all records, with a density of 6.0 records per km 2 . Of the grand total of all the fauna records, 7% were of threatened species. Birds and mammals comprise 81% of all fauna records in the Atlas. The greatest number of records are of birds (n = 4,913,511), followed by mammals (n = 832,361, of which 321,721, or 39%, were from WildCount). Given the success of the growth of the number, area and distribution of parks and reserves in NSW, the idea that they can carry the heavy load of the aspiration to conserve the biodiversity of NSW now seems feasible, even desirable, especially given the increasing intensity of land use from never–ending population growth and its impacts, such as land clearing, roading, logging, water use, alien invasive species and climate change. However, this study has also revealed that we have a very poor understanding of some faunal groups, in particular invertebrates, reptiles and amphibians. Fauna accumulation curves of both records and of species match closely the growth in the area of parks and reserves since the formation of the NSW National Parks and Wildlife Service in 1967. Thus, the greater the area of parks and reserves, the greater the number of fauna records and of species. We took the historical view so that research is encouraged and the trajectory of the acquisition of new protected areas can be maintained. This study shows the ever–increasing value of protected areas to fauna conservation, and that it is vital to uphold the protected areas concept as a principal way to conserve our fauna. It should also be a guide to help recognise the importance of sustaining the effort to study our native fauna.

The Central West and Lachlan Catchments lie west of the Great Dividing Range in central NSW and have been subjected to extensive land clearing, grazing and agricultural pressures beginning in the 1820s. Many vertebrate species are known to have disappeared from these catchments but reliable data for species diversity, distribution, abundance and conservation status are not available. For this assessment of the diversity and status of the vertebrate fauna in these catchment areas a comprehensive database of vertebrate records was established, species distributions mapped, faunal communities determined by pattern analysis and conservation status determined at a regional level. The extent of post-European human-induced landscape change was evaluated by assessing the degree of habitat loss, loss of landscape function and resilience through changes to the water cycle, soil and energy flow and the impact of invasive species, diseases and agricultural pollution. Of the 595 vertebrate species verified for these catchments, 6% are introduced, 12% have been listed in NSW under the Threatened Species Conservation Act 1995 , 4% by the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 , 40% are regionally vulnerable, 20% regionally endangered and 2% likely to have become extinct in the region. Overall we estimate that 64% (382) of species are declining. These statistics present a grim picture of the survival of vertebrates in these catchments and potentially for the sheep-wheat belt of eastern Australia. The extreme loss of habitat and its poor condition across much of these catchments followed by serious changes to the functioning of the landscape provide clear reasons for the catastrophic decline of vertebrates in this landscape. If this serious decline in the Central West and Lachlan catchments is to be halted, strategies aimed at habitat and landscape restoration must be developed. Current strategies based on Threatened Species management plans and ad hoc planting for revegetation have not produced results. We need a radical rethink.

ABSTRACT Many invasive species have had negative effects on the Australian environment, including the introduced Sambar Deer (Rusa unicolor) . However, there is a paucity of information on the factors influencing the fine scale distribution and abundance patterns of Sambar Deer in south-eastern Australia. We present the results of a field survey of Sambar Deer in the Critically Endangered Mountain Ash ( Eucalyptus regnans ) forests of the Central Highlands, Victoria. Our key question was: What factors influence detections of Sambar deer (based on scat counts) within the Mountain Ash forests of the Victorian Central Highlands? We surveyed 86 long-term field sites and detected a total of 245 groups of Sambar Deer pellets on 42% of these sites. Negative binomial regression modelling identified three factors associated with the occurrence of deer pellets. We recorded more pellets: (1) in 30 and 80 year old forest that remained unburned in fires that occurred in 2009, (2) on sites within closed National Parks relative to sites in State Forest, and (3) close to streams.

The red fox Vulpes vulpes is one of the most destructive invasive species in mainland Australia and has recently been introduced to Tasmania. This paper reports the results of a survey conducted in Tasmania in mid-2006, to ascertain the public's views about foxes, their presence in Tasmania and what, if anything, should be done about them if, in fact, they are present. The survey found that public opinion among Tasmanians surveyed was overwhelmingly and vehemently opposed to the presence of foxes and indicated a high public expectation that there would be action by the authorities, scientists and others to remove them and/or prevent their further entry to the State. The minority of respondents who dissented from this view were chiefly in the “don't know” category, and required further information. The variation in responses by age to this and other questions indicates the desirability of a stronger communication focus on younger Tasmanians about foxes, the risks they pose and the need to use scientific methods to control them.

ABSTRACT We describe a case of a free-ranging Carpet Python Morelia spilota consuming a toxic Cane Toad Rhinella marina , and dying as a result. Such an encounter would not be surprising at the toad invasion front, where predators first confront this novel prey type. However, the encounter we describe occurred at a site near Darwin where toads have been present for fifteen years. Other reports suggest that the behaviour we observed occurs across the snake’s range. Lethal ingestion of toads has been suggested to threaten the viability of populations of Carpet Pythons, but paradoxically, our surveys at this site reveal a twofold increase in abundance of Carpet Pythons since the arrival of toads. Toad invasion likely has favoured pythons by reducing the abundance of large monitor lizards, that are both predators and competitors of Carpet Pythons. That advantage has outweighed occasional cases where a snake is fatally poisoned by consuming a toad. Thus, the overall impact of Cane Toads on Carpet Pythons (and likely, other predator species) is a balance between direct costs and indirect benefits. Negative impacts on individuals may not necessarily translate to a negative impact on the species.

Introduced species have made a major contribution to the degradation of aquatic wetlands throughout the world and particularly in Australia. One species, Red-Eared Slider Trachemys scripta elegans , classified among the world's top 100 most invasive pest species, has established populations in Australia, most extensively in South-eastern Queensland. A decade ago a small established population was identified in a wetland in Southern Sydney in Yeramba Lagoon. We re-visited this population a decade on to determine its status and the impact on the two resident native freshwater turtle species, Chelodina longicollis Eastern Long Necked Turtle and Emydura macquarii dharuk Sydney Basin Turtle. We captured similar numbers of red-eared sliders as a decade before but increased number of the two native species. There was therefore no indication that the feral species was currently at a competitive advantage over the native species.

Until recently, biotic distributions were largely dictated by the interactions of dispersal, evolution, and plate tectonics (Huggett 2004; Cox and Moore 2005). Now, merchandise and people are transported at unprecedented rates in an embrace of globalisation, thereby providing pathways for flora and fauna to breach previously impervious geographic barriers (Lowe et al. 2000; Stachowicz et al. 2002). Despite Australia's geographic isolation, it has not escaped this phenomenon as there are an estimated 80 invasive, non-indigenous vertebrate species, an order of magnitude more for invertebrates, and approximately 2700 species of non-indigenous plant that have established populations in Australia (Low 1999; Bomford and Hart 2002; Pimentel 2002).

ABSTRACT The exotic pet trade may be the principal mechanism for the establishment of invasive reptile species. The escape or deliberate release of captive reptiles has resulted in the establishment of many species globally. In Australia, exposure to this entry pathway has been limited due to long-term legislation preventing the importation and keeping of exotic reptiles by private keepers. Despite this, the corn snake Elaphe guttata is still illegally maintained in many private collections, resulting in occasional reports of released or escaped specimens. We recorded 79 free-ranging corn snakes captured by three wildlife organizations between 2002 and 2014 in the greater Sydney region, Australia. There was an increasing encounter rate over time, suggesting that this is a growing problem and may result in the establishment and spread of this species into Australia. Corn snakes were recorded throughout the Sydney region. No snake clusters were found and this suggests that populations may not have become established in the wild yet.

The cane toad Bufo marinus is well recognised as a threat to biodiversity in northern Australia. Concern about this impact has grown in recent years as the species spreads geographically. Previous estimates of the potential distributional limits of B. marinus have excluded high elevation rainforest, largely based on thermal tolerances and known habitat preferences. This paper reports on the detection of B. marinus over a five-year study in the Border Ranges National Park in northern NSW. More than 400 toads were detected in rainforests at elevations between 810 m and 1130 m, with all captures being made along an isolated section of road within the reserve. No breeding was observed, all captures were of adults and nearly all appeared to be female. The indications are that toads migrated through heavily forested steep escarpment to the east, rather than along the road network and thus represent a significant emerging threat to the entire reserve. Models predicting the distributional limits of B. marinus will need to consider a broader range of elevations, habitat types and thermal tolerances than has been previously considered. Further research is urgently required to understand the threat this invasion may pose to the unique biodiversity of this World Heritage Area and attempt to mitigate the threat.

ABSTRACT Natural environments are now much reduced or modified, with the consequence that many species have declined and become imperilled. However, such modifications have also led to range expansion or population increases in some other native species. Consequently, in an increasing number of situations, the viability of a threatened native species is now being compromised by another native species, and conservation managers must consider options for how best to make decisions about and manage such situations. Here, I provide Australian examples of the many variations of the issue of managing to favour one native species at the expense of another native species, and note that the issue is likely to be of increasing incidence, extent, complexity and societal interest. Whereas there are reasonably well-established policy and legal foundations, and general societal support, for killing invasive (‘pest’ or ‘weed’) species to benefit native species, there is far less well-developed context and regulatory basis for the issue of killing native species to benefit other native species, and it may evoke considerable community concerns. Given the moral complexities of this issue, I use and apply the long-established ‘Just War’ theory as a pathway to develop a simple decision tree approach and a set of principles to guide decision-making when considering the need to kill a native species to achieve a conservation objective. These principles are that: (i) every effort should first be made to redress any ultimate factor responsible for the ecological imbalance; (ii) there should be compelling evidence that the ‘increaser’ species (‘Species A’) has a significant detrimental impact on the species of conservation concern (‘Species B’); (iii) there should be compelling evidence that reduction in the abundance of Species A will lead to a significant and enduring enhancement of the conservation outlook for Species B; (iv) reduction in the abundance of Species A will have no significant impact on its conservation status; (v) consequently, any program of killing Species A should be predicated on a net biodiversity benefit; (vi) options other than killing have been adequately evaluated as a mechanism to reduce the impact of Species A on Species B; (vii) any killing of Species A is done as humanely as possible; (viii) all relevant information on the situation is provided publicly with opportunity for public comment prior to decision-making; (ix) where there is insufficient information about any proposed culling, a carefully-designed trial should be applied, with results used to guide subsequent decision-making; (x) the management actions and biodiversity responses are monitored and reported publicly.