Sensor-Based Detection of Predator Influence on Livestock: A Case Study Exploring the Impacts of Wild Dogs (Canis familiaris) on Rangeland Sheep

Simple Summary

Sheep predation by wild dogs has serious production and animal welfare implications. By monitoring changes in the behaviour of sheep, on-animal sensors are an option for detecting wild dogs and alerting producers to their presence. This study identified differences in the daily distance travelled of sheep when in the presence and absence of a wild dog and highlights the potential for on-animal sensors to be used as a monitoring and management tool for wild dog detection.

Abstract

In Australia, wild dogs are one of the leading causes of sheep losses. A major problem with managing wild dogs in Australia’s rangeland environments is that sheep producers are often unaware of their presence until injuries or deaths are observed. One option for earlier detection of wild dogs is on-animal sensors, such as Global Positioning System (GPS) tracking collars, to detect changes in the behaviour of sheep due to the presence of wild dogs. The current study used spatio-temporal data, derived from GPS tracking collars, deployed on sheep from a single rangeland property to determine if there were differences in the behaviour of sheep when in the presence, or absence, of a wild dog. Results indicated that the presence of a wild dog influenced the daily behaviours of sheep by increasing the daily distance travelled. Differences in sheep diurnal activity were also observed during periods where a wild dog was present or absent on the property. These results highlight the potential for on-animal sensors to be used as a monitoring tool for sheep flocks directly impacted by wild dogs, although further work is needed to determine the applicability of these results to other sheep production regions of Australia.

On the right track: placement of camera traps on roads improves detection of predators and shows non-target impacts of feral cat baiting

Abstract ContextTo understand the ecological consequences of predator management, reliable and accurate methods are needed to survey and detect predators and the species with which they interact. Recently, poison baits have been developed specifically for lethal and broad-scale control of feral cats in Australia. However, the potential non-target effects of these baits on other predators, including native apex predators (dingoes), and, in turn, cascading effects on lower trophic levels (large herbivores), are poorly understood. AimsWe examined the effect that variation in camera trapping-survey design has on detecting dingoes, feral cats and macropodids, and how different habitat types affect species occurrences. We then examined how a feral cat poison baiting event influences the occupancy of these sympatric species. MethodsWe deployed 80 remotely triggered camera traps over the 2410-km2 Matuwa Indigenous Protected Area, in the semiarid rangelands of Western Australia, and used single-season site-occupancy models to calculate detection probabilities and occupancy for our target species before and after baiting. Key resultsCameras placed on roads were ~60 times more likely to detect dingoes and feral cats than were off-road cameras, whereas audio lures designed to attract feral cats had only a slight positive effect on detection for all target species. Habitat was a significant factor affecting the occupancy of dingoes and macropodids, but not feral cats, with both species being positively associated with open woodlands. Poison baiting to control feral cats did not significantly reduce their occupancy but did so for dingoes, whereas macropodid occupancy increased following baiting and reduced dingo occupancy. ConclusionsCamera traps on roads greatly increase the detection probabilities for predators, whereas audio lures appear to add little or no value to increasing detection for any of the species we targeted. Poison baiting of an invasive mesopredator appeared to negatively affect a non-target, native apex predator, and, in turn, may have resulted in increased activity of large herbivores. ImplicationsManagement and monitoring of predators must pay careful attention to survey design, and lethal control of invasive mesopredators should be approached cautiously so as to avoid potential unintended negative ecological consequences (apex-predator suppression and herbivore release).

Status and Magnitude of Grey Wolf Conflict with Pastoral Communities in the Foothills of the Hindu Kush Region of Pakistan

Simple Summary

Despite higher loss due to disease, human–carnivore conflicts over livestock depredation is one of the major problems in carnivore conservation, both locally and globally. Locals share negative attitudes towards the wolf due to conflicts over livestock depredation. Using semi-structured questionnaires, we found that grey wolf is in a serious conflict with the locals, causing economic loss to them at the expanse of its own life. The locals considered the species a serious threat to their livestock, causing them economic losses, and wanted to reduce or even eliminate it from their area. Respondents having larger herd size and higher dependency on livestock for earning livelihoods shared more negative attitudes towards the wolves. In our study area the economic loss of the locals due to livestock mortalities from diseases was higher than that from wolf depredation. Therefore, we suggested that vaccination of the livestock and compensation schemes will help to change the perception of locals towards wolf.

Abstract

Pastoralist–wolf conflict over livestock depredation is the main factor affecting conservation of grey wolf worldwide. Very limited research has been carried out to evaluate the pattern and nature of livestock depredation by wolf. This study aims to determine the status and nature of human–wolf conflict across different villages in the Hind Kush region of Pakistan during the period January 2016–December 2016. For this purpose, a total of 110 local male respondents from all walks of life were interviewed using a semi-structured questionnaire. The grey wolf was declared as a common species in the area by 51.3% of the locals with an annual sighting rate of 0.46 each. During the year (2016), a total of 358 livestock were lost to grey wolf predation and disease. Of the total livestock loss, grey wolf was held responsible for a total 101 livestock losses. Goat and sheep were the most vulnerable prey species as they accounted for 80 (79.2%) of the total reported depredations. Out of the total economic loss (USD 46,736, USD 424.87/household), grey wolf was accountable for USD 11,910 (USD 108.27 per household), while disease contributed 34,826 (USD 316.6 per household). High depredation was observed during the summer season 58.42% (n = 59) followed by spring and autumn. Unattended livestock were more prone to grey wolf attack during free grazing in forests. Most of the respondents (75.45%) showed aggressive and negative attitudes towards grey wolf. The herders shared more negative attitude (z = −3.21, p = 0.001) than businessman towards the species. Herders having larger herd size displayed more deleterious behavior towards wolves than those having smaller herd size. Active herding techniques, vaccinating livestock, educating locals about wildlife importance, and initiating compensating schemes for affected families could be helpful to decrease negative perceptions.

Using Audience Segmentation to Understand Nonparticipation in Invasive Mammal Management in Australia

Invasive mammals threaten agriculture, biodiversity, and community health. Yet many landholders fail to engage in control activities recommended by experts. We surveyed a representative sample of 731 Western Australian rural landholders. The survey assessed landholders' participation in a range of activities to control invasive mammals, as well as their capabilities, opportunities, and motivation for engaging in such activities. We found that over half of our respondents had not participated in any individual or group activities to control invasive mammals during the previous 12 months. Using latent profile analysis, we identified six homogeneous subgroups of nonparticipating landholders, each with their distinct psycho-graphic profiles: Unaware, Unskilled, and Unmotivated, Aware but Unskilled and Doubtful, Unskilled and Time Poor, Disinterested, Skilled but Dismissive, and Capable but Unmotivated. Our results indicate that engagement specialists should not treat nonparticipating landholders as a single homogeneous group. Nonparticipators differ considerably in terms of their capabilities, opportunities, and motivations, and require targeted engagement strategies informed by these differences.

Mortality and morbidity in wild Taiwanese pangolin (Manis pentadactyla pentadactyla)

Globally, pangolins are threatened by poaching and illegal trade. Taiwan presents a contrary situation, where the wild pangolin population has stabilized and even begun to increase in the last two decades. This paper illustrates the factors responsible for causing mortality and morbidity in the wild Taiwanese pangolin (Manis pentadactyla pentadactyla) based on radio-tracking data of wild pangolins and records of sick or injured pangolins admitted to a Taiwanese wildlife rehabilitation center. Despite being proficient burrowers, results from radio-tracking show that Taiwanese pangolins are highly susceptible to getting trapped in tree hollows or ground burrows. Data from Pingtung Rescue Center for Endangered Wild Animals showed that trauma (73.0%) was the major reason for morbidity in the Taiwanese pangolin with trauma from gin traps being the leading cause (77.8%), especially during the dry season, followed by tail injuries caused by dog attacks (20.4%). Despite these threats, Taiwan has had substantial success in rehabilitating and releasing injured pangolins, primarily due to the close collaboration of Taiwanese wildlife rehabilitation centers over the last twenty years.

First report of nymphs of the introduced pentastomid, Linguatula serrata, in red-necked wallabies (Notamacropus rufogriseus) in Australia

The presence of nymphs of the introduced pentastomid parasite Linguatula serrata is verified in a native Australian animal, the red-necked wallaby (Notamacropus rufogriseus), for the first time. Morphological and genetic analyses confirmed the species identification, with a 100% genetic match to samples collected from various introduced animals from the same location in Kosciuszko National Park. Previous reports of pentastomids, including possible Linguatula sp. infections, in native animals are discussed. More research is required to confirm the validity of these reports.

Elucidating biogeographical patterns in Australian native canids using genome wide SNPs

Dingoes play a strong role in Australia's ecological framework as the apex predator but are under threat from hybridization and agricultural control programs. Government legislation lists the conservation of the dingo as an important aim, yet little is known about the biogeography of this enigmatic canine, making conservation difficult. Mitochondrial and Y chromosome DNA studies show evidence of population structure within the dingo. Here, we present the data from Illumina HD canine chip genotyping for 23 dingoes from five regional populations, and five New Guinea Singing Dogs to further explore patterns of biogeography using genome-wide data. Whole genome single nucleotide polymorphism (SNP) data supported the presence of three distinct dingo populations (or ESUs) subject to geographical subdivision: southeastern (SE), Fraser Island (FI) and northwestern (NW). These ESUs should be managed discretely. The FI dingoes are a known reservoir of pure, genetically distinct dingoes. Elevated inbreeding coefficients identified here suggest this population may be genetically compromised and in need of rescue; current lethal management strategies that do not consider genetic information should be suspended until further data can be gathered. D statistics identify evidence of historical admixture or ancestry sharing between southeastern dingoes and South East Asian village dogs. Conservation efforts on mainland Australia should focus on the SE dingo population that is under pressure from domestic dog hybridization and high levels of lethal control. Further data concerning the genetic health, demographics and prevalence of hybridization in the SE and FI dingo populations is urgently needed to develop evidence based conservation and management strategies.

Managing conflict between large carnivores and livestock

Large carnivores are persecuted globally because they threaten human industries and livelihoods. How this conflict is managed has consequences for the conservation of large carnivores and biodiversity more broadly. Mitigating human-predator conflict should be evidence-based and accommodate people's values while protecting carnivores. Despite much research into human and large-carnivore coexistence strategies, there have been few attempts to document the success of conflict-mitigation strategies on a global scale. We conducted a meta-analysis of global research on conflict mitigation related to large carnivores and humans. We focused on conflicts that arise from the threat large carnivores pose to livestock. We first used structured and unstructured searching to identify replicated studies that used before-after or control-impact design to measure change in livestock loss as a result of implementing a management intervention. We then extracted relevant data from these studies to calculate an overall effect size for each intervention type. Research effort and focus varied among continents and aligned with the histories and cultures that shaped livestock production and attitudes toward carnivores. Livestock guardian animals most effectively reduced livestock losses. Lethal control was the second most effective control, although its success varied the most, and guardian animals and lethal control did not differ significantly. Financial incentives have promoted tolerance of large carnivores in some settings and reduced retaliatory killings. We suggest coexistence strategies be location-specific, incorporate cultural values and environmental conditions, and be designed such that return on financial investment can be evaluated. Improved monitoring of mitigation measures is urgently required to promote effective evidence-based policy.

Spatially-explicit model for assessing wild dog control strategies in Western Australia

Large predators can significantly impact livestock industries. In Australia, wild dogs (Canis lupus familiaris, Canis lupus dingo, and hybrids) cause economic losses of more than AUD$40M annually. Landscape-scale exclusion fencing coupled with lethal techniques is a widely practiced control method. In Western Australia, the State Barrier Fence encompasses approximately 260,000km² of predominantly agricultural land, but its effectiveness in preventing wild dogs from entering the agricultural region is difficult to evaluate. We conducted a management strategy evaluation (MSE) based on spatially-explicit population models to forecast the effects of upgrades to the Western Australian State Barrier Fence and several control scenarios varying in intensity and spatial extent on wild dog populations in southwest Western Australia. The model results indicate that populations of wild dogs on both sides of the State Barrier Fence are self-sustaining and current control practices are not sufficient to effectively reduce their abundance in the agricultural region. Only when a combination of control techniques is applied on a large scale, intensively and continuously are wild dog numbers effectively controlled. This study identifies the requirement for addressing extant populations of predators within fenced areas to meet the objective of preventing wild dog expansion. This objective is only achieved when control is applied to the whole area where wild dogs are currently present within the fence plus an additional buffer of ~20 km. Our modelling focused on the use of baiting, trapping and shooting; however, we acknowledge that additional tools may also be applied. Finally, we recommend that a cost-benefit analysis be performed to evaluate the economic viability of an integrated control strategy.

Conservation implications for dingoes from the maternal and paternal genome: Multiple populations, dog introgression, and demography

It is increasingly common for apex predators to face a multitude of complex conservation issues. In Australia, dingoes are the mainland apex predator and play an important role in ecological functioning. Currently, however, they are threatened by hybridization with modern domestic dogs in the wild. As a consequence, we explore how increasing our understanding of the evolutionary history of dingoes can inform management and conservation decisions. Previous research on whole mitochondrial genome and nuclear data from five geographical populations showed evidence of two distinct lineages of dingo. Here, we present data from a broader survey of dingoes around Australia using both mitochondrial and Y chromosome markers and investigate the timing of demographic expansions. Biogeographic data corroborate the presence of at least two geographically subdivided genetic populations, southeastern and northwestern. Demographic modeling suggests that dingoes have undergone population expansion in the last 5,000 years. It is not clear whether this stems from expansion into vacant niches after the extinction of thylacines on the mainland or indicates the arrival date of dingoes. Male dispersal is much more common than female, evidenced by more diffuse Y haplogroup distributions. There is also evidence of likely historical male biased introgression from domestic dogs into dingoes, predominately within southeastern Australia. These findings have critical practical implications for the management and conservation of dingoes in Australia; particularly a focus must be placed upon the threatened southeastern dingo population.

The longevity of para-aminopropiophenone (PAPP) wild dog baits and the implications for effective and safe baiting campaigns

Considerable effort goes into mitigating the impacts caused by invasive animals and prohibiting their establishment or expansion. In Australia, management of wild dogs (Canis lupus dingo and their hybrids) and their devastating impacts is reliant upon poison baiting. The recent release of baits containing the humane toxin para-aminopropiophenone (PAPP) offers potential improvements for control of wild dogs, but little is known about the environmental persistence of PAPP in manufactured baits that could be used to inform best practice guidelines. We investigated the degradation rate of PAPP wild dog baits (DOGABAIT™) under typical field usage and storage conditions in north-eastern Australia and calculated optimal deployment and withholding periods. The PAPP content of buried baits declines faster than surface-laid baits, but both presentations retained lethal doses to wild and domestic dogs for considerable periods (6-16 weeks). Domestic or working dogs should be suitably restrained or excluded from baited areas for extended periods, particularly under dry conditions, to minimise poisoning risk. The period of persistence of PAPP baits may provide opportunities to improve the duration or longer term efficacy of baiting campaigns, but care is needed to protect domestic and working dogs to ensure responsible and safe use.

Guardian dogs protect sheep by guarding sheep, not by establishing territories and excluding predators

Guardian animals have been a common non-lethal method for reducing predator impacts on livestock for centuries in Europe. But elsewhere, livestock producers sometimes doubt whether such methods work or are compatible with modern livestock husbandry practices in extensive grazing systems. In this study we evaluate the hypothesis that guardian dogs primarily ‘work’ by establishing and defending territories from which canid predators are excluded. Eight maremmas and six free-ranging wild dogs of different sexes were fitted with GPS collars and monitored for 7 months on a large sheep property in north Queensland, Australia. Wild dog incursions into the territories of adjacent wild dogs and maremmas were recorded. Wild dog territories never overlapped and their home ranges infrequently overlapped. In contrast, 713 hourly locations from 120 wild dog incursions into maremma territories were recorded, mostly from three wild dogs. These three wild dogs spent a mean of 2.5–5.9 h inside maremma territories during incursions. At this location, maremmas worked by guarding sheep and prohibiting fine-scale interaction between wild dogs and sheep, not by establishing a territory respected by wild dogs. We conclude that shepherding behaviour and boisterous vocalisations of guardian dogs combined with the flocking behaviour of sheep circumvents attacks on sheep but does not prevent nor discourage wild dogs from foraging in close proximity. Certain husbandry practices and the behaviour of sheep at parturition may incur greater predation risk.

Placing invasive species management in a spatiotemporal context

Invasive species are a worldwide issue, both ecologically and economically. A large body of work focuses on various aspects of invasive species control, including how to allocate control efforts to eradicate an invasive population as cost effectively as possible: There are a diverse range of invasive species management problems, and past mathematical analyses generally focus on isolated examples, making it hard to identify and understand parallels between the different contexts. In this study, we use a single spatiotemporal model to tackle the problem of allocating control effort for invasive species when suppressing an island invasive species, and for long-term spatial suppression projects. Using feral cat suppression as an illustrative example, we identify the optimal resource allocation for island and mainland suppression projects. Our results demonstrate how using a single model to solve different problems reveals similar characteristics of the solutions in different scenarios. As well as illustrating the insights offered by linking problems through a spatiotemporal model, we also derive novel and practically applicable results for our case studies. For temporal suppression projects on islands, we find that lengthy projects are more cost effective and that rapid control projects are only economically cost effective when population growth rates are high or diminishing returns on control effort are low. When suppressing invasive species around conservation assets (e.g., national parks or exclusion fences), we find that the size of buffer zones should depend on the ratio of the species growth and spread rate.

Death by sex in an Australian icon: a continent-wide survey reveals extensive hybridization between dingoes and domestic dogs

Hybridization between domesticated animals and their wild counterparts can disrupt adaptive gene combinations, reduce genetic diversity, extinguish wild populations and change ecosystem function. The dingo is a free-ranging dog that is an iconic apex predator and distributed throughout most of mainland Australia. Dingoes readily hybridize with domestic dogs, and in many Australian jurisdictions, distinct management strategies are dictated by hybrid status. Yet, the magnitude and spatial extent of domestic dog-dingo hybridization is poorly characterized. To address this, we performed a continent-wide analysis of hybridization throughout Australia based on 24 locus microsatellite DNA genotypes from 3637 free-ranging dogs. Although 46% of all free-ranging dogs were classified as pure dingoes, all regions exhibited some hybridization, and the magnitude varied substantially. The southeast of Australia was highly admixed, with 99% of animals being hybrids or feral domestic dogs, whereas only 13% of the animals from remote central Australia were hybrids. Almost all free-ranging dogs had some dingo ancestry, indicating that domestic dogs could have poor survivorship in nonurban Australian environments. Overall, wild pure dingoes remain the dominant predator over most of Australia, but the speed and extent to which hybridization has occurred in the approximately 220 years since the first introduction of domestic dogs indicate that the process may soon threaten the persistence of pure dingoes.

Interspecific and geographic variation in the diets of sympatric carnivores: dingoes/wild dogs and red foxes in south-eastern Australia

Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna. We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia. The nine regions encompass a wide variety of ecosystems. Diet overlap between dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size. The key mammalian food items for dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus). Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; dingoes/wild dogs consumed greater biomass of the smaller fox. The substantial geographic variation in diet indicates that dingoes/wild dogs and foxes alter their diet in accordance with changing food availability. We provide checklists of taxa recorded in the diets of dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on dingoes/wild dogs, foxes and the food resources they interact with.

Canine rabies in Australia: a review of preparedness and research needs

Australia is unique as a populated continent in that canine rabies is exotic, with only one likely incursion in 1867. This is despite the presence of a widespread free-ranging dog population, which includes the naturalized dingo, feral domestic dogs and dingo-dog cross-breeds. To Australia's immediate north, rabies has recently spread within the Indonesian archipelago, with outbreaks occurring in historically free islands to the east including Bali, Flores, Ambon and the Tanimbar Islands. Australia depends on strict quarantine protocols to prevent importation of a rabid animal, but the risk of illegal animal movements by fishing and recreational vessels circumventing quarantine remains. Predicting where rabies will enter Australia is important, but understanding dog population dynamics and interactions, including contact rates in and around human populations, is essential for rabies preparedness. The interactions among and between Australia's large populations of wild, free-roaming and restrained domestic dogs require quantification for rabies incursions to be detected and controlled. The imminent risk of rabies breaching Australian borders makes the development of disease spread models that will assist in the deployment of cost-effective surveillance, improve preventive strategies and guide disease management protocols vitally important. Here, we critically review Australia's preparedness for rabies, discuss prevailing assumptions and models, identify knowledge deficits in free-roaming dog ecology relating to rabies maintenance and speculate on the likely consequences of endemic rabies for Australia.

The short-term effects of a routine poisoning campaign on the movements and detectability of a social top-predator

Top-predators can be important components of resilient ecosystems, but they are still controlled in many places to mitigate a variety of economic, environmental and/or social impacts. Lethal control is often achieved through the broad-scale application of poisoned baits. Understanding the direct and indirect effects of such lethal control on subsequent movements and behaviour of survivors is an important pre-requisite for interpreting the efficacy and ecological outcomes of top-predator control. In this study, we use GPS tracking collars to investigate the fine-scale and short-term movements of dingoes (Canis lupus dingo and other wild dogs) in response to a routine poison-baiting program as an example of how a common, social top-predator can respond (behaviourally) to moderate levels of population reduction. We found no consistent control-induced differences in home range size or location, daily distance travelled, speed of travel, temporal activity patterns or road/trail usage for the seven surviving dingoes we monitored immediately before and after a typical lethal control event. These data suggest that the spatial behaviour of surviving dingoes was not altered in ways likely to affect their detectability, and if control-induced changes in dingoes' ecological function did occur, these may not be related to altered spatial behaviour or movement patterns.

A pilot study into the use of global navigation satellite system technology to quantify the behavioural responses of sheep during simulated dog predation events

The predation of sheep (Ovis aries) by wild and domestic dogs (Canis lupis) is a major issue in Australia, causing serious welfare issues to inflicted animals. The estimated cost of sheep and cattle production losses caused by wild dogs when combined with an extensive range of control measures, costs the Australian economy AU$66 million annually. Spatio-temporal data derived from global navigation satellite system (GNSS) devices were used to quantify the behavioural responses of two flocks of 15 Merino ewes ranging from 2 to 8 years old (average 4.5 years) during simulated dog predation events. Each sheep was fitted with a GNSS collar, and the behavioural responses of the sheep were video recorded during six trials (three per flock). The behavioural data collated from video recordings were then compared with the movement metrics derived from the GNSS collars. Derived metrics include the spatial distribution of flock members, speed of animal movement and specific behavioural changes including centripetal rotation (circling behaviour of the flock, with individual sheep seeking the centre). While the spatial distribution data did not appear to be specific enough to enable identification of a predation event, the velocity of sheep was higher (P < 0.001) during compared with before and after a simulated dog predation event. Centripetal rotation occurred in 80% of the simulated predation events during this study, and may provide a means for identifying predation. The spatio-temporal data from GNSS devices have potential as a research tool to assist in understanding sheep movement patterns during a dog attack. While further research and mathematical modelling of predation events is clearly required, the application of remote sensing technology has the potential to improve future livestock monitoring.

Aerially deployed baits in the northern rangelands of Western Australia are available to wild dogs

Context Aerial baiting using fixed-wing aircraft is an effective method of bait delivery for wild-dog control in remote locations. However, aerial baiting may result in loss of baits to positions that are inaccessible to wild dogs. Attempts, by landholders, to address such bait loss through compensatory baiting may increase baiting costs and potential risks to non-target species. Aims To assess bait drift under standard baiting conditions. To assess the availability of aerially deployed baits to wild dogs across several commonly baited landforms in the northern rangelands of Western Australia. Methods We determined drift characteristics of baits deployed under standard fixed-wing baiting conditions. We then determined the availability of aerially deployed baits by deploying baits with embedded radio-transmitters across four commonly baited landforms (riparian vegetation, tussock grassland, gorges and breakaways). We then visually assessed the availability of relocated baits (as ‘high’, ‘moderate’ or ‘low’). Key results Under standard fixed-wing baiting conditions, on average, baits fell 100.9 m forward, and 8.3 m laterally, from the point-of-release. Across all landforms, most baits (91.8%) were highly available, with a further 7.0% falling into the moderate category and 1.2% in the low category. There were significant differences in bait availability among landforms, with the proportion of moderate-low availability baits greatest in gorges and lowest on tussock grassland. Conclusions Within the northern rangelands of Western Australia, bait wastage owing to deployment in inaccessible locations is minimal. Implications Compensatory baiting for lost baits is unnecessary and increases costs to land managers.

Cautionary considerations for positive dingo management: a response to the Johnson and Ritchie critique of Fleming et al. (2012)

Johnson and Ritchie (2012) have provided a criticism of our opinion piece (Fleming et al. 2012). There is some common ground, but we remain unconvinced by their view that our reasoning was unsound or beside the point. In this response, we discuss where Johnson and Ritchie have provided unconvincing evidence to refute our seven considerations, and reiterate and demonstrate why these considerations remain important. The mesopredator release or suppression hypothesis in Australian ecosystems must be objectively evaluated before positive management of dingoes and other free-ranging dogs is recommended or implemented. Adaptive comanagement of free-ranging dogs can be used for both biodiversity conservation and the mitigation of livestock predation but caution must be exercised when considering using free-ranging dogs as a conservation tool.

Seven considerations about dingoes as biodiversity engineers: the socioecological niches of dogs in Australia

Australian dingoes have recently been suggested as a tool to aid biodiversity conservation through the reversal or prevention of trophic cascades and mesopredator release. However, at least seven ecological and sociological considerations must be addressed before dog populations are positively managed.Domestication and feralisation of dingoes have resulted in behavioural changes that continue to expose a broad range of native and introduced fauna to predation.Dingoes and other dogs are classic mesopredators, while humans are the apex predator and primary ecosystem engineers in Australia.Anthropogenic landscape changes could prevent modern dingoes from fulfilling their pre-European roles.Dingoes are known to exploit many of the same species they are often presumed to ‘protect’, predisposing them to present direct risks to many threatened species.The assertion that contemporary dog control facilitates the release of mesopredators disregards the realities of effective dog control, which simultaneously reduces fox and dog abundance and is unlikely to enable increases in fox abundance.The processes affecting threatened fauna are likely a combination of both top-down and bottom-up effects, which will not be solved or reversed by concentrating efforts on managing only predator effects.Most importantly, human social and economic niches are highly variable across the ecosystems where dingoes are present or proposed. Human perceptions will ultimately determine acceptance of positive dingo management.Outside of an adaptive management framework, positively managing dingoes while ignoring these seven considerations is unlikely to succeed in conserving native faunal biodiversity but is likely to have negative effects on ecological, social and economic values.

Top predators as biodiversity regulators: the dingo Canis lupus dingo as a case study

Top-order predators often have positive effects on biological diversity owing to their key functional roles in regulating trophic cascades and other ecological processes. Their loss has been identified as a major factor contributing to the decline of biodiversity in both aquatic and terrestrial systems. Consequently, restoring and maintaining the ecological function of top predators is a critical global imperative. Here we review studies of the ecological effects of the dingo Canis lupus dingo, Australia's largest land predator, using this as a case study to explore the influence of a top predator on biodiversity at a continental scale. The dingo was introduced to Australia by people at least 3500 years ago and has an ambiguous status owing to its brief history on the continent, its adverse impacts on livestock production and its role as an ecosystem architect. A large body of research now indicates that dingoes regulate ecological cascades, particularly in arid Australia, and that the removal of dingoes results in an increase in the abundances and impacts of herbivores and invasive mesopredators, most notably the red fox Vulpes vulpes. The loss of dingoes has been linked to widespread losses of small and medium-sized native mammals, the depletion of plant biomass due to the effects of irrupting herbivore populations and increased predation rates by red foxes. We outline a suite of conceptual models to describe the effects of dingoes on vertebrate populations across different Australian environments. Finally, we discuss key issues that require consideration or warrant research before the ecological effects of dingoes can be incorporated formally into biodiversity conservation programs.

Integrating science into management of ecosystems in the Greater Blue Mountains

Effective management of large protected conservation areas is challenged by political, institutional and environmental complexity and inconsistency. Knowledge generation and its uptake into management are crucial to address these challenges. We reflect on practice at the interface between science and management of the Greater Blue Mountains World Heritage Area (GBMWHA), which covers approximately 1 million hectares west of Sydney, Australia. Multiple government agencies and other stakeholders are involved in its management, and decision-making is confounded by numerous plans of management and competing values and goals, reflecting the different objectives and responsibilities of stakeholders. To highlight the complexities of the decision-making process for this large area, we draw on the outcomes of a recent collaborative research project and focus on fire regimes and wild-dog control as examples of how existing knowledge is integrated into management. The collaborative research project achieved the objectives of collating and synthesizing biological data for the region; however, transfer of the project's outcomes to management has proved problematic. Reasons attributed to this include lack of clearly defined management objectives to guide research directions and uptake, and scientific information not being made more understandable and accessible. A key role of a local bridging organisation (e.g., the Blue Mountains World Heritage Institute) in linking science and management is ensuring that research results with management significance can be effectively transmitted to agencies and that outcomes are explained for nonspecialists as well as more widely distributed. We conclude that improved links between science, policy, and management within an adaptive learning-by-doing framework for the GBMWHA would assist the usefulness and uptake of future research.

Assessment of risks to non-target species from an encapsulated toxin in a bait proposed for control of feral cats

Context The CURIOSITY® bait is the name coined for a variation of the existing sausage-style cat bait, ERADICAT®. The latter is used under experimental permit in Western Australia for research associated with cat control. The CURIOSITY bait differs from ERADICAT by providing a pH-buffered (less acidic) medium and has been proposed to reduce the risk to non-target species by encapsulating a toxin in a pellet. We trialled a prototype pellet proposed for encapsulation of 1080 and/or alternative toxins, with delivery proposed through the CURIOSITY bait. Aim Our aim was to determine whether the pellet was consumed by non-target native species from south-west of Western Australia. Methods Trials involved use of a non-toxic biomarker, Rhodamine B, encapsulated within the pellet and inserted into the CURIOSITY® bait. Uptake of the encapsulated biomarker was assessed in captive trials for the target species, the feral cat (Felis catus) and two non-target species of varanid lizard, Rosenberg’s goanna (Varanus rosenbergi) and Gould’s goanna (V. gouldii) and the non-target mammal species chuditch (Dasyurus geoffroii) and southern brown bandicoot (Isoodon obesulus). Uptake of the encapsulated biomarker was also assessed in field trials for a range of native species. Key results Captive trials demonstrated feral cats will consume the CURIOSITY bait and pellet. However, results from captive and field trials indicated several non-target species also consumed the bait and pellet. We also found the pellet itself was not sufficiently robust for use in a bait. As with previously reported studies, we found Rhodamine B to be an effective biomarker for use in cats. We also developed a technique whereby Rhodamine B can be used as a biomarker in reptiles. However, its use as a biomarker in other mammalian species was confounded by what appeared to be background, or pre-existing, levels of fluorescence, or banding, in their whiskers. Conclusion The prototype pellet is unsuitable in its current form for use with the CURIOSITY bait. We caution that the CURIOSITY bait has non-target issues in south-west of Western Australia and any proposed variations to this bait, or the ERADICAT® bait, need to be rigorously assessed for their potential risk to non-target species and assessed for the level of uptake by cats, irrespective of their suitability/unsuitability as a medium for delivery of an encapsulated toxin. We believe the threat to biodiversity-conservation values from unmitigated feral-cat predation of native fauna poses a significant and real threat and we recommend urgent investment of resources to address the issue of cat predation in a coordinated and collaborative manner within Australia and New Zealand.

Australian dingoes are definitive hosts of Neospora caninum

To provide objective data on the potential role of dingoes (Canis lupus dingo) in the life cycle of Neospora caninum in Australia, the production of N. caninum oocysts by experimentally infected canids was investigated. Three dingo pups raised in captivity and three domestic dogs were fed tissue from calves infected with an Australian isolate of N. caninum, Nc-Nowra. Oocysts of N. caninum, confirmed by species-specific PCR, were shed in low numbers by one dingo pup at 12-14 days p.i. The remaining animals did not shed oocysts. Furthermore, the blood from two out of three dingoes tested positive for DNA of N. caninum using PCR tests at 14 and 28 days p.i. Oocyst shedding from the intestinal tract of a dingo demonstrates that dingoes are definitive hosts of N. caninum and horizontal transmission of N. caninum from dingoes to farm animals and wildlife may occur in Australia.

A review of chemical, biological and fertility control options for the camel in Australia

Since their introduction to Australia in 1840 the one-humped camel, Camelus dromedarius, has gone from the colonist’s companion to a conservationist’s conundrum in the fragile arid ecosystems of Australia. Current management techniques are failing to curb present population growth and alternatives must be sought. This review assess the applicability of currently registered and developmental vertebrate pesticides and fertility control agents for camel control, as well as examining the potential usefulness of known C. dromedarius diseases for biological control. Not surprisingly, little is known about the lethality of most vertebrate pesticides used in Australia to camels. More has been published on adverse reactions to pharmaceuticals used in agriculture and the racing industry. An examination of the literature on C. dromedarius diseases, such as camel pox virus, contagious ecthyma and papillomatosis, indicates that the infections generally result in high morbidity but not necessarily mortality and this alone may not justify their consideration for use in Australia. The possibility exists that other undiscovered or unstudied biological control agents from other camilid species may offer greater potential for population control. As a long-lived species the camel is also not ideally suited to fertility control. Notwithstanding, anti-fertility agents may have their place in preventing the re-establishment of camel populations once they have been reduced through mechanical, biological or chemical means. Delivery of any generic chemical or fertility control agent will, however, require a species-tailored pathway and an appropriate large-scale deployment method. Accordingly, we put forward avenues of investigation to yield improved tools for camel control.

Prevalence of threatened native species in canid scats from coastal and near-coastal landscapes in south-eastern Australia

Predator scat analysis was used to infer the potential impact of wild dogs (Canis lupus dingo, C. l. familiaris and hybrids of the two) on threatened native terrestrial mammals in coastal and near-coastal southern New South Wales, Australia. Prey items recorded in wild dog scats were compared with those occurring in scats of the red fox collected at the same study sites. Six threatened mammal species were recorded in either wild dog or fox scats: eastern pygmy possum, grey-headed flying fox, long-nosed potoroo, southern brown bandicoot, white-footed dunnart and yellow-bellied glider. The prevalence of these threatened species in fox scats was significantly higher than in wild dog scats. Otherwise, wild dogs mostly consumed larger prey items such as swamp wallabies and wombats whereas foxes more heavily preyed on small mammals such as antechinus and rats. Our results suggest that foxes are the major threat to threatened mammal species in the study region. Land management agencies in south-eastern mainland Australia should therefore focus on controlling foxes for biodiversity gain.

Aerial baiting with 1080 to control wild dogs does not affect the populations of two common small mammal species

More than most other animal control techniques, toxic baiting is fraught with the potential impact on non-target species. In the present study, we investigated the effect of aerial baiting with 1080 to control wild dogs in north-eastern New South Wales (NSW), Australia, on populations of southern bush rats (Rattus fuscipes assimilis) and brown antechinus (Antechinus stuartii), using a controlled experiment. Six populations, three each within widely spaced baited and unbaited trapping grids, were monitored before and after bait laying. To develop capture–mark–recapture indices, separate 4-day trapping surveys were undertaken twice before and twice after meat baits (250 g containing 6 mg sodium fluoroacetate, 1080) were delivered from a helicopter at 40 baits per kilometre. To assess non-fatal bait consumption, all baits contained rhodamine B (RhB), which gets incorporated into the vibrissae of animals that have ingested this marker. Neither mammal population decreased in size after baiting, nor was there any increase in population turnover rates or changes in the movement patterns of either species. Furthermore, no trapped animal tested positive for RhB, suggesting that these small mammals rarely consume meat baits, and that, at the population level, the impact of baiting on them was likely negligible. It is therefore unlikely that the current practise of aerial baiting in NSW, although effective in reducing dog activity, threatens populations of these two common species and perhaps small mammals in general.

Additional toxins for feral pig (Sus scrofa) control: identifying and testing Achilles' heels

A literature review was conducted in order to identify unique weaknesses in the physiology or metabolism of pigs that could be targeted with specific chemicals (i.e. an ‘Achilles’ heel’ search). A promising weakness identified was the species’ susceptibility to methaemoglobin-forming compounds, most likely related to their uniquely low levels of methaemoglobin reductase. Further examination revealed that sodium nitrite is a cost-effective, readily available methaemoglobin-forming compound that is highly toxic to domestic pigs, which has caused numerous accidental poisonings. Pen trials on pigs showed that sodium nitrite delivered by gavage (>90 mg kg−1) and freely consumed in bait (>400 mg kg−1) caused rapid and lethal rises in methaemoglobin. Sodium nitrite appeared to be more humane than currently used toxins, with deaths following bait consumption being considerably quicker and with fewer symptoms (within 80 min of clinical signs beginning; clinical signs including infrequent vomiting, lethargy, ataxia and dyspnoea). The review also identified a second deficiency in the metabolism of pigs, namely high sensitivity to selective inhibition of cytochrome P450 liver enzymes. This leads to potentially lethal interactions between various drugs, such as two antibiotics, monensin and tiamulin. A pen trial confirmed that the antibiotic combination in a single gavage dose was reliably and rapidly lethal to pigs. However, its utility as a pig toxin is low, because it was unpalatable to pigs when delivered in bait and appeared to cause pain and suffering (leading to the early termination of pen trials). The findings presented here demonstrate the potential of sodium nitrite as an additional feral pig toxin.

Oral toxicity of p-aminopropiophenone to ferrets

Ferrets (Mustela furo) are pests in New Zealand and new methods are being sought for their control. The hydrochloride form of p-aminopropiophenone (PAPP) was highly toxic to ferrets when delivered by gavage, with LD50 and LD99 values of 15.52 and 20.80 mg kg–1, respectively. Signs of toxicosis progressed through pallor and cyanosis, impaired coordination, prostration with reduced responses to stimuli, with death in ~2 h. In a preliminary assessment of effective doses of PAPP in bait, 19 of 20 ferrets consumed chick carcasses containing ~46 mg PAPP within 40 min. Ferrets that ate chick baits all showed signs of toxicosis, with 32% mortality. Three ferrets died within 151 min and the other three within the following 14 h. Ferrets that died ingested 29.9–79.3 mg PAPP per kilogram bodyweight. The low mortality was attributed to decreased bioavailability of PAPP delivered in food, and increased doses need to be tested to establish an effective lethal concentration of PAPP in baits for ferrets. Future development of bait formulations will also need to take into account the role of emesis in reducing efficacy. Bait formulations incorporating microencapsulated PAPP may improve bioavailability and the basis for a new option for the management of ferrets in New Zealand.