Camera traps are widely used in wildlife research and monitoring, so it is imperative to understand their strengths, limitations, and potential for increasing impact. We investigated a decade of use of wildlife cameras (2012-2022) with a case study on Australian terrestrial vertebrates using a multifaceted approach. We (i) synthesised information from a literature review; (ii) conducted an online questionnaire of 132 professionals; (iii) hosted an in-person workshop of 28 leading experts representing academia, non-governmental organisations (NGOs), and government; and (iv) mapped camera trap usage based on all sources. We predicted that the last decade would have shown: (i) exponentially increasing sampling effort, a continuation of camera usage trends up to 2012; (ii) analytics to have shifted from naive presence/absence and capture rates towards hierarchical modelling that accounts for imperfect detection, thereby improving the quality of outputs and inferences on occupancy, abundance, and density; and (iii) broader research scales in terms of multi-species, multi-site and multi-year studies. However, the results showed that the sampling effort has reached a plateau, with publication rates increasing only modestly. Users reported reaching a saturation point in terms of images that could be processed by humans and time for complex analyses and academic writing. There were strong taxonomic and geographic biases towards medium-large mammals (>500g) in forests along Australia's southeastern coastlines, reflecting proximity to major cities. Regarding analytical choices, bias-prone indices still accounted for similar to 50% of outputs and this was consistent across user groups. Multi-species, multi-site and multiple-year studies were rare, largely driven by hesitancy around collaboration and data sharing. There is no widely used repository for wildlife camera images and the Atlas of Living Australia (ALA) is the dominant repository for sharing tabular occurrence records. However, the ALA is presence-only and thus is unsuitable for creating detection histories with absences, inhibiting hierarchical modelling. Workshop discussions identified a pressing need for collaboration to enhance the efficiency, quality and scale of research and management outcomes, leading to the proposal of a Wildlife Observatory of Australia (WildObs). To encourage data standards and sharing, WildObs should (i) promote a metadata collection app; (ii) create a tagged image repository to facilitate artificial intelligence/machine learning (AI/ML) computer vision research in this space; (iii) address the image identification bottleneck via the use of AI/ML-powered image-processing platforms; (iv) create data commons for detection histories that are suitable for hierarchical modelling; and (v) provide capacity building and tools for hierarchical modelling. Our review highlights that while Australia's investments in monitoring biodiversity with cameras position it to be a global leader in this context, realising that potential requires a paradigm shift towards best practices for collecting, curating, sharing and analysing 'Big Data'. Our findings and framework have broad applicability outside Australia to enhance camera usage to meet conservation and management objectives ranging from local to global scales. This review articulates a country/continental observatory approach that is also suitable for international collaborative wildlife research networks.
Small island populations are vulnerable to genetic decline via demographic and environmental stochasticity. In the absence of immigration, founder effects, inbreeding and genetic drift are likely to contribute to local extinction risk. Management actions may also have a greater impact on small, closed populations. The demographic and social characteristics of a species can, however, delay the impact of threats. K’gari, a 1 660 km2 island off the Australian east coast and UNESCO World Heritage Site (Fraser Island 1842–2023), supports an isolated population of approximately 70–200 dingoes that represent an ideal opportunity to explore the small island paradigm. To examine temporal and spatial patterns of genetic diversity in this population we analysed single nucleotide polymorphism (SNP) genotype data (72 454 SNPS) for 112 K’gari dingoes collected over a 25-year period (1996 to 2020). Genetic diversity was lower in K’gari dingoes than mainland dingoes at the earliest time point in our study and declined significantly following a management cull in 2001. We did not find any spatial genetic patterns on the island, suggesting high levels of genetic connectivity between socially discrete packs. This connectivity, combined with the social structure and behaviour of dingoes, may act in concert to buffer the population from the impacts of genetic drift in the short term. Nevertheless, a general decline in genetic variation via inbreeding and drift has occurred over the past 20 years which we suggest should be considered in any future management planning for the population. Monitoring patterns of genetic variation, together with a clearer understanding of the social ecology of K’gari dingoes, will aid in the development of measurable genetic targets set over ecologically meaningful timelines, and help ensure continued survival of this culturally important population.
Context Managing human–wildlife conflict where anthropogenic resources are provided is difficult. Providing food, water and shelter can result in over-abundant dingo populations, especially in Australian desert mine sites where managing dingoes, wildlife and humans around waste-management facilities and camps is problematic. Aims To measure and characterise the spatial activities of a population of arid-zone dingoes in relation to resources provided by a Cooper Basin (Strzelecki Desert, South Australia mining operation). The results were used to facilitate effective dingo management. Methods Free-roaming dingoes were captured, their morphometrics and ectoparasite presence recorded, and they were fitted with Iridium (GPS) radio collars. These were used to collect high-fidelity data about individual dingo activity and movements in relation to mine-site infrastructure and the Cooper Basin ecosystem. Key results A high density of dingoes (181 trapped in 2 km2 per 4 years) was associated with the mining operation. Home range/activity area sizes and usage of the anthropogenic landscape showed the following three categories of dingo: desert, peripatetic and tip dingoes. Dingoes reliant on food provisioning at the waste-management facility (WMF) displayed activity areas with a strong focus on the WMF (tip dingoes). Temporal activity patterns of another group of dingoes (peripatetic dingoes) were associated with regular waste-dumping times and normal nocturnal activity away from the WMF. Of the 27 dingoes collared, 30% (i.e. desert dingoes) were not dependent on the WMF, spending more time and a greater area of use in the desert dune system than in the mine-site area. Conclusions On the basis of the capture of 181 dingoes over 4 years and home-range analysis, it is likely that anthropogenic resource provisioning has caused an overabundance of dingoes in the Cooper Basin mine site. However, some of the dingo population remains reliant on native wildlife and resources in the surrounding desert. Managing food waste and excluding dingoes from food, water and shelter will result in a change in the prevalence of dingoes in the mine site, and subsequent reduction in the risk of disease transmission, native wildlife impacts, human conflicts and social pressures on dingoes, influencing them to revert to domestic-dog behaviours. Implications Waste-management facilities where food is dumped provide resources that lead to a change in wild-dingo behaviour, on the basis of their acceptance of human-provided resources, and high abundance. Managing access to anthropogenic resources will reduce the population as well as unwanted or aggressive encounters with humans. Dingoes reliant on food scraps will be encouraged to adjust their activity areas to desert habitat, thereby providing natural hunting opportunities and reduced contact rates with conspecifics, thus potentially reducing pathogen transmission.
The available science often demonstrates the need for feral horse population control but not the degree of control required to achieve environmental conservation objectives. To better manage the influence of feral horses, we must first understand the relationship between feral horse density and environmental impact. We recorded vegetation and soil disturbance, and the sign of potential causes of this impact in two parts of the Australian Alps, the Bogong high plains (BHP) and the Eastern Victorian Alps (EVA). We calculated density‐impact functions to assist managers with determining feral horse density targets for control programmes. Minimal sign of feral horse impact was detected on the BHP, with no impact of feral horses observed along 99% of the length of transects. In contrast, impacts assigned to feral horses were significantly higher in the EVA, where a larger, higher‐density population of feral horses existed. However, greater than 83% of the walked transect length was still undisturbed by feral horses in the EVA. We detected a threshold of horse impact at ~ 250 horse faecal piles per ha. Above this threshold, a slight increase in horse density resulted in a disproportionately large increase in impact. In this context, a relatively small population control effort may substantially reduce direct horse impact. But where horse densities exist below this threshold, considerably more expense and control effort (resulting from the difficulties related to control at low density) is likely to make very little difference to an already low level of direct impact. The combined impacts associated with the sign of deer, feral pigs, fire and humans were large compared to that of feral horses. Management of feral horses to reduce their direct impact is unlikely to be beneficial without complementary management to reduce the effects of these other agents of impact.
GPS tracking collars were fitted to five free-ranging dogs (Canis familiaris) in the Arcadia Valley, Queensland to establish baseline movement data in this unique topographical landscape. Activity areas were generated with three home range methods using seasonally constrained fixes. Activity areas (Brownian Bridge and Utilisation Distribution) ranged from 2.9 to 689 km2 in this landscape, and revealed that topographical features previously thought to confine free-ranging dog movement were no barrier to habitat use.
Understanding the exchange of individuals between wildlife populations, particularly those with naturally fragmented habitats, is important for the effective management of these species. This is of particular consequence when the species is of conservation concern, and isolated populations may be lost due to pressures from predation or competition, or catastrophic events such as wildfire. Here we demonstrate the use kinship and population structure analysis to show potential recent movement between colonies in metapopulations of yellow-footed rock-wallaby ( Petrogale xanthopus Gray 1854) at two sites in the Grey Range of Queensland, and at four sites in the Gawler Ranges of South Australia. These colonies are also compared to a single colony from the Flinders Ranges, a connected landscape of rock-wallaby habitat. Using reduced representation next-generation sequencing, we acquired and filtered a set of ~ 17,000 single-nucleotide polymorphisms to examine population genetic variation, structure and relationships within populations, and also identify putative migrants. Initial STRUCTURE analysis re-confirmed each population should be considered separately. Tests of population genetic variation identify several colonies appearing to be experiencing genetic erosion, also with low calculated effective population sizes (N e = 4.5–36.6). Pairwise comparisons of individual relatedness (relatedness coeffiecients; r ) implied several contemporary movement events between colonies within both the Gawler and Grey Ranges ( r > 0.125), which was then affirmed with tests for putative first generation migrants. These results are of particular note in South Australia, where threat abatement (management of key predators and competitors) may facilitate dispersion. Additionally, in Queensland, colonies are separated by anthropogenic barriers: predator exclusion fencing designed to exclude dingoes ( Canis familiaris ) from grazing land, which may hinder dispersal. This work highlights the usefulness of population genetics to inform management outcomes in wildlife, in this case, highlighting the need for threatened species management at the landscape level.
Increased demand for livestock products is exacerbating conflict with predators in many parts of the world, fuelling an increase in predation management practices in many grazing systems. In Australia, exclusion fences are being erected across broad areas to facilitate the sustained eradication of dingoes, an apex predator, prompting concern for possible cascading effects on extant wildlife populations. We experimentally assessed population trends of mammals, reptiles and ground-dwelling birds inside and outside of two large, fenced areas over a five-year period subsequent to the erection of the fences and the removal of dingoes. Wildlife population abundances inside the fences were always higher or the same as outside the fences, and all wildlife species exhibited similar population trends within each treatment over time. The only exception to this was kangaroo populations, which fluctuated widely inside fenced areas but remained relatively low and stable outside fenced areas. Kangaroos exhibited negative relationships with dingoes, although unmeasured variables limited our ability to quantify specific causes for kangaroo population trends. Vegetation trends were virtually identical between treatments, indicating that wildlife population trends are closely linked to vegetation conditions and not predator abundances. These applied, experimental results demonstrate that top-predator removal does not routinely cause trophic cascades (including mesopredator releases) in Australian rangeland ecosystems. We therefore encourage exploration of opportunities for targeted threatened species recovery in predator-free areas on land used for livestock production.
Removal or loss of top-predators has been predicted to cause cascading negative effects for ecosystems, including mesopredator release. However, reliable evidence for these processes in terrestrial systems has been mixed and equivocal due, in large part, to the systemic and continued use of low-inference study designs to investigate this issue. Even previous large-scale manipulative experiments of strong inferential value have been limited by experimental design features (i.e. failure to prevent migration between treatments) that constrain possible inferences about the presence or absence of mesopredator release effects. Here, we build on these previous strong-inference experiments and report the outcomes of additional large-scale manipulative experiments to eradicate Australian dingoes from two fenced areas where dingo migration was restricted and where theory would predict an increase in extant European red foxes, feral cats and goannas. We demonstrate the removal and suppression of dingoes to undetectable levels over 4–5 years with no corresponding increases in mesopredator relative abundances, which remained low and stable throughout the experiment at both sites. We further demonstrate widespread absence of negative relationships between predators, indicating that the mechanism underpinning predicted mesopredator releases was not present. Our results are consistent with all previous large-scale manipulative experiments and long-term mensurative studies which collectively demonstrate that (1) dingoes do not suppress red foxes, feral cats or goannas at the population level, (2) repeated, temporary suppression of dingoes in open systems does not create mesopredator release effects, and (3) removal and sustained suppression of dingoes to undetectable levels in closed systems does not create mesopredator release effects either. Our experiments add to similar reports from North America, Asia, Europe and southern Africa which indicate that not only is there a widespread absence of reliable evidence for these processes, but there is also a large and continually growing body of experimental evidence of absence for these processes in many terrestrial systems. We conclude that although sympatric predators may interact negatively with each other on smaller spatiotemporal scales, that these negative interactions do not always scale-up to the population level, nor are they always strong enough to create mesopredator suppression or release effects.
Predator density changes can alter behaviours of prey, and removal of predators is expected to free prey from predation risks. Due to pest management activities within predator exclusion fences in central-western Queensland, Australia, dingoes (Canis familiaris) have been actively controlled in places also inhabited by endangered yellow-footed rock-wallabies (YFRW, Petrogale xanthopus). These pest management practices are expected to enable YFRW to utilise otherwise riskier habitats, though the occurrence of these processes remain unclear. Here, we assessed the responses of YFRW habitat use to pest species management in exclusion fences. In congruence with previous work, we find the likelihood of YFRW presence is positively correlated with increasing habitat complexity (r = 0.39). Greater coverage of ground and shrub vegetation also correlated positively with YFRW presence (p < 0.05). However, we found no difference in YFRW habitat selection inside and outside exclusion fences, which was considered to be an artefact of populations of predators still surviving inside the fence, along with insufficient elapsed time to adequately assess behavioural responses by YFRW since the construction of the fence. These results support the view that even small numbers of predators can have a limiting effect on threatened prey and/or that researchers must allow sufficient time to observe prey responses to changes in predation risk.
Exclusion fencing is a common tool used to mitigate a variety of unwanted economic losses caused by problematic wildlife. While the potential for agricultural, ecological and economic benefits of pest animal exclusion are often apparent, what is less clear are the costs and benefits to sympatric non-target wildlife. This review examines the use of exclusion fencing in a variety of situations around the world to elucidate the potential outcomes of such fencing for wildlife and apply this knowledge to the recent uptake of exclusion fencing on livestock properties in the Australian rangelands. In Australia, exclusion fences are used to eliminate dingo (Canis familiaris dingo) predation on livestock, prevent crop-raiding by emus (Dromaius novaehollandiae), and enable greater control over total grazing pressure through the reduction of macropods (Macropodidae) and feral goats (Capra hircus). A total of 208 journal articles were examined for location, a broad grouping of fence type, and the reported effects the fence was having on the study species. We found 51% of the literature solely discusses intended fencing effects, 42% discusses unintended effects, and only 7% considers both. Africa has the highest proportion of unintended effects literature (52.0%) and Australia has the largest proportion of literature on intended effects (34.2%). We highlight the potential for exclusion fencing to have positive effects on some species and negative effects on others (such as predator exclusion fencing posing a barrier to migration of other species), which remain largely unaddressed in current exclusion fencing systems. From this review we were able to identify where and how mitigation strategies have been successfully used in the past. Harnessing the potential benefits of exclusion fencing while avoiding the otherwise likely costs to both target and non-target species will require more careful consideration than this issue has previously been afforded.
The global effort to conserve threatened species relies heavily on our ability to separate these species from the processes that threaten them, and a common tool used for this purpose is exclusion fencing. In Australia, pest animal exclusion fencing has been repeatedly used on conservation land on a small scale to successfully exclude introduced predators and competitors from threatened native fauna populations. However, in recent years, "cluster fencing" on agricultural land has re-emerged on a large scale and is used by livestock producers seeking to reduce predation losses by dingoes (Canis familiaris) and manage total grazing pressure from native and introduced herbivores, including red kangaroos (Osphranter rufus). Given that the primary threats to at-risk native fauna are also predation and overgrazing, there may be potential for cluster fencing on livestock land to achieve additional fauna conservation benefits. Understanding the amount, location and potential conservation value of cluster fenced livestock land is critical for determining how these areas might contribute to broader threatened fauna recovery goals. Drawing from publicly available databases maintained by the Australian Government, we assessed the spatial overlap of threatened species' distributions with 105 cluster fences erected in Queensland since 2013, which cover 65,901 km2 of land. These cluster fenced areas represent 18 biogeographic subregions and may contain 28 extant threatened mammals, birds and reptiles including 18 vulnerable species, 7 endangered species and 3 critically endangered species. An average of nine threatened species or their habitats were identified per cluster, and over three quarters (78.6%) of these species face at least one threat that is being mitigated within clusters. The true status of threatened and pest species within clusters is largely unknown or unrecorded in most cases, but some examples of pest eradication and threatened species recovery are already emerging. Given the vast size of the cluster fenced estate, the many different biomes and species that it represents and the nature of the threats being removed within these fenced areas, we contend that agricultural cluster fencing may offer an unprecedented opportunity to advance threatened fauna conservation goals for some species at scales previously thought impossible and should be a research priority for threatened species managers.
The origins of feral cats in Australia may be understood with the help of molecular studies, but it is important that hypotheses be tested with appropriate sampling and methodology. We point out several shortcomings in the analysis by Koch et al. (BMC Evol Biol 15:262, 2015; A voyage to Terra Australis: human-mediated dispersal of cats. Dryad Digital Repository, 2015), present a reanalysis of part of the study and discuss the challenges of elucidating the early history of feral cats.