Peter J. S. Fleming

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.

A strategic approach to mitigating the impacts of wild canids: proposed activities of the Invasive Animals Cooperative Research Centre

Wild canids (wild dogs and European red foxes) cause substantial losses to Australian livestock industries and environmental values. Both species are actively managed as pests to livestock production. Contemporaneously, the dingo proportion of the wild dog population, being considered native, is protected in areas designated for wildlife conservation. Wild dogs particularly affect sheep and goat production because of the behavioural responses of domestic sheep and goats to attack, and the flexible hunting tactics of wild dogs. Predation of calves, although less common, is now more economically important because of recent changes in commodity prices. Although sometimes affecting lambing and kidding rates, foxes cause fewer problems to livestock producers but have substantial impacts on environmental values, affecting the survival of small to medium-sized native fauna and affecting plant biodiversity by spreading weeds. Canid management in Australia relies heavily on the use of compound 1080-poisoned baits that can be applied aerially or by ground. Exclusion fencing, trapping, shooting, livestock-guarding animals and predator calling with shooting are also used. The new Invasive Animals Cooperative Research Centre has 40 partners representing private and public land managers, universities, and training, research and development organisations. One of the major objectives of the new IACRC is to apply a strategic approach in order to reduce the impacts of wild canids on agricultural and environmental values in Australia by 10%. In this paper, the impacts, ecology and management of wild canids in Australia are briefly reviewed and the first cooperative projects that will address IACRC objectives for improving wild dog management are outlined.

Reintroducing the dingo: the risk of dingo predation to threatened vertebrates of western New South Wales

Abstract Context. The reintroduction of dingoes into sheep-grazing areas south-east of the dingo barrier fence has been suggested as a mechanism to suppress fox and feral-cat impacts. Using the Western Division of New South Wales as a case study, Dickman et al. (2009) recently assessed the risk of fox and cat predation to extant threatened species and concluded that reintroducing dingoes into the area would have positive effects for most of the threatened vertebrates there, aiding their recovery through trophic cascade effects. However, they did not formally assess the risk of dingo predation to the same threatened species. Aims. To assess the risk of dingo predation to the extant and locally extinct threatened vertebrates of western New South Wales using methods amenable to comparison with Dickman et al. (2009). Methods. The predation-risk assessment method used in Dickman et al. (2009) for foxes and cats was applied here to dingoes, with minor modification to accommodate the dietary differences of dingoes. This method is based on six independent biological attributes, primarily reflective of potential vulnerability characteristics of the prey. Individual-attribute scores were used to derive an overall risk score. Key results. Up to 75 (94%) of the 80 extant species were predicted to be at risk of dingo predation (71% at high risk) regardless of any effect dingoes might have on foxes or cats. Up to 17 of the 21 (81%) locally extinct species were predicted to be at high risk of dingo predation using this approach. The re-establishment of even low-density dingo populations may have negative effects on at least 22% of extant threatened vertebrates. Conclusions. The generic risk-assessment method was insensitive, and experienced difficulty in describing the true nature of canid predation risk. Despite this weakness, however, it is clear that several threatened vertebrates are susceptible to dingo predation. Prior to the re-establishment of dingoes, we recommend that dingo predation risks to all vertebrates (threatened or otherwise) be assessed using more sensitive and descriptive techniques, and we strongly caution against the positive management of dingoes under current ecological conditions. Implications. The results of this study imply that dingoes present similar levels of direct risk to threatened species as foxes and feral cats, and dingo predation of threatened species should be formally considered in any proposal encouraging dingo populations in western New South Wales.

The success of GPS collar deployments on mammals in Australia

Global Positioning System (GPS) wildlife telemetry collars are being used increasingly to understand the movement patterns of wild mammals. However, there are few published studies on which to gauge their general utility and success. This paper highlights issues faced by some of the first researchers to use GPS technology for terrestrial mammal tracking in Australia. Our collated data cover 24 studies where GPS collars were used in 280 deployments on 13 species, including dingoes or other wild dogs (Canis lupus dingo and hybrids), cats (Felis catus), foxes (Vulpes vulpes), kangaroos (Macropus giganteus), koalas (Phascolarctos cinereus), livestock guardian dogs (C. l. familiaris), pademelons (Thylogale billardierii), possums (Trichosurus cunninghami), quolls (Dasyurus geoffroii and D. maculatus), wallabies (Macropus rufogriseus and Petrogale lateralis), and wombats (Vombatus ursinus). Common problems encountered were associated with collar design, the GPS, VHF and timed-release components, and unforseen costs in retrieving and refurbishing collars. We discuss the implications of collar failures for research programs and animal welfare, and suggest how these could be avoided or improved. Our intention is to provide constructive advice so that researchers and manufacturers can make informed decisions about using this technology, and maximise the many benefits of GPS while reducing the risks.

Anthropogenic Resource Subsidies Determine Space Use by Australian Arid Zone Dingoes: An Improved Resource Selection Modelling Approach

Dingoes (Canis lupus dingo) were introduced to Australia and became feral at least 4,000 years ago. We hypothesized that dingoes, being of domestic origin, would be adaptable to anthropogenic resource subsidies and that their space use would be affected by the dispersion of those resources. We tested this by analyzing Resource Selection Functions (RSFs) developed from GPS fixes (locations) of dingoes in arid central Australia. Using Generalized Linear Mixed-effect Models (GLMMs), we investigated resource relationships for dingoes that had access to abundant food near mine facilities, and for those that did not. From these models, we predicted the probability of dingo occurrence in relation to anthropogenic resource subsidies and other habitat characteristics over ∼ 18,000 km2. Very small standard errors and subsequent pervasively high P-values of results will become more important as the size of data sets, such as our GPS tracking logs, increases. Therefore, we also investigated methods to minimize the effects of serial and spatio-temporal correlation among samples and unbalanced study designs. Using GLMMs, we accounted for some of the correlation structure of GPS animal tracking data; however, parameter standard errors remained very small and all predictors were highly significant. Consequently, we developed an alternative approach that allowed us to review effect sizes at different spatial scales and determine which predictors were sufficiently ecologically meaningful to include in final RSF models. We determined that the most important predictor for dingo occurrence around mine sites was distance to the refuse facility. Away from mine sites, close proximity to human-provided watering points was predictive of dingo dispersion as were other landscape factors including palaeochannels, rocky rises and elevated drainage depressions. Our models demonstrate that anthropogenically supplemented food and water can alter dingo-resource relationships. The spatial distribution of such resources is therefore critical for the conservation and management of dingoes and other top predators.

Some human, aircraft and animal factors affecting aerial surveys: how to enumerate animals from the air

Aerial surveys of wildlife involve a noisy platform carrying one or more observers moving over animals in order to quantify their abundance. This simple-sounding system encapsulates limits to human visual acuity and human concentration, visual attention, salience of target objects within the viewed scene, characteristics of survey platforms and facets of animal behaviours that affect the detection of animals by the airborne observers. These facets are too often ignored in aerial surveys, yet are inherent sources of counting error. Here we briefly review factors limiting the ability of observers to detect animals from aerial platforms in a range of sites, including characteristics of the aircraft, observers and target animals. Some of the previously uninvestigated limitations identified in the review were studied in central and western New South Wales, showing that inaccuracies of human memory and enumeration processes are sources of bias in aerial survey estimates. Standard protocols that minimise or account for the reviewed factors in aerial surveys of wildlife are recommended.

Managing feral goat impacts by manipulating their access to water in the rangelands

Feral goats are a significant threat to biodiversity in Australia. However, goats are also harvested by some landholders for commercial benefit and this can lead to disagreements regarding control techniques. In the rangelands of New South Wales, feral goat distribution is closely linked to artificial watering points (AWP) such as tanks and bores. Previous surveys indicated that goat activity was rare more than 4 km from water. We hypothesised that constructing sections of goat-proof fencing in areas where goats were feeding on National Parks but watering on neighbouring properties, such that they had to travel more than 4 km from the AWP to access the park, would result in a significant decrease in goat abundance in these areas. We tested this hypothesis in Paroo-Darling National Park, Gundabooka State Conservation Area and Gundabooka National Park using changes in index (fresh goat dung groups per 100-m transect). We also measured kangaroo dung and ground cover index changes. Twelve months after the fences were constructed, goat dung significantly declined compared with non-treatment areas and the relationship between distance to water and goat dung broke down at the treatment sites. Kangaroo indices were not affected by the fences. The results for bare ground were the same as for goat dung, with significantly less bare ground and a breakdown in the relationship with distance to water at the treatment sites after the fences were constructed, but this was due to a corresponding increase in litter rather than live vegetation. This technique can be a significant tool for protecting biodiversity from feral goats, without removing the potential for neighbouring landholders to harvest the goats. If strategically used to create zones free of resident goats around the boundaries of conservation reserves, it should increase the effectiveness of other techniques such as trapping, mustering and shooting, by reducing post-control reinvasion. Recognition of access to water as an important management tool should substantially improve our management of feral goats in the rangelands.

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.

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.

Genetic profile of dingoes (Canis lupus dingo) and free-roaming domestic dogs (C. l. familiaris) in the Tanami Desert, Australia

Abstract Context. Many rare and endangered species are threatened by the effects of hybridisation with their domesticated and often numerically dominant relatives. However, factors that influence interactions between hybridising species are poorly understood, thus limiting our ability to develop ameliorative strategies. Aims. Here, we identify family groups and investigate patterns of gene flow between dingoes (Canis lupus dingo) and domestic dogs (C. l. familiaris) in the Tanami Desert of central Australia. We aimed to determine whether human-provided resources facilitate hybridisation or alter typical patterns of dingo breeding and social behaviour. We also ask whether remote townships are arenas for dingo–dog hybridisation. Methods. Tissue samples and morphological details were collected from dingo-like animals around two mine sites where humans provide abundant supplementary food and water. Using molecular DNA analyses, we assigned animals to population clusters, determined kinship and the numbers of family groups. Rates of hybridisation were assessed around the mines and in two nearby townships. Key results. Of 142 samples from mine sites, ‘pure’ dingoes were identified genetically in 89% of cases. This predominance of dingoes was supported by our observations on coat colour and body morphology. Only 2 of 86 domestic dogs sampled at the two townships showed evidence of dingo ancestry. Around the mine sites, there were two distinct population clusters, including a large family group of 55 individuals around a refuse facility. Conclusions. Where superabundant and consistent food, and reliable water, was available, dingo packs were much larger and co-existed with others, contrary to expectations derived from previous research. Dingo sociality and pack structures can therefore be altered where human-provided food and water are constantly available, and this could facilitate accelerated rates of hybridisation. Implications. The development of appropriate domestic-waste management strategies should be a high priority in remote areas to ensure only normal rates of population increase by dingoes, and other canids more broadly. It will also potentially impede hybridisation rates if typical canid social and behavioural traits remain intact. Additionally, areas surrounding remote human settlements are likely arenas for accentuated dingo–domestic dog interactions and should be a target for future studies.