Output list
Journal article
Published 2025
Ecology and evolution, 15, 4, e71328
Most human‐carnivore conflicts arise from the impact of predation on livestock. In Australian rangelands, considerable resources are allocated to constructing exclusion fences and implementing control measures to manage dingo populations for sustainable livestock enterprise. Assessing the effectiveness of these measures is crucial for justifying the investment. We used a replicated experimental design to examine the effect of landscape‐scale dingo‐proof exclusion fences (‘cell‐fencing’) on activity and population density of dingoes in the Southern Rangelands of Western Australia. We monitored dingo populations for 22–24 months across six study sites nested within a landscape of about 75,000 km2 and defined ‘fence level’ as the number of dingo‐proof fences enclosing each study site. We used camera trap capture rate (number of independent capture events per 100 trap nights) as a metric for dingo activity (including the availability of resources as other potential covariates), estimated dingo density using spatially explicit mark‐resight models, and tested the relationship between capture rate and estimated density of dingoes for each study site. Significant variation in both metrics was observed between sites and across time. Fence level and prey occurrence significantly influenced dingo activity. The annual mean dingo density estimate across study sites was below two dingoes per 100 km2 (i.e., 0.02 dingoes per km2; the maximum value believed to be compatible with small livestock) at only one study site in the first year, but it was higher across all sites during the second year of monitoring. Dingo activity correlated with estimated dingo density at only two sites, suggesting differences in dingo behaviour and detection across the six study sites. This study provides experimental evidence that camera trap capture rate is not a reliable method for assessing variations in the population size of dingoes. These results have implications for monitoring outcomes of dingo control programs across Australia.
This study addresses a critical question: How reliable is the activity metric (here we used camera trap capture rate) to assess variations in population size of dingoes across diverse habitats in Australia? Through experimental evidence, we demonstrate that activity metrics can lead to inaccuracies in assessing changes in dingo population size. Our findings highlight the need to assess dingo population size from identified individuals, which is particularly relevant for effective dingo control programs across Australia.
Journal article
Balancing the books of nature by accounting for ecosystem condition following ecological restoration
Published 2024
Scientific reports, 14, 11369
Demand for ecological restoration of Earth's degraded ecosystems has increased significantly since the adoption of The Kunming-Montreal Global Biodiversity Framework in December 2022, with target 2 aiming to ensure that at least 30% of degraded ecosystems are under effective restoration by 2030. More recently, in December 2023, the Australian Parliament introduced the Nature Repair Act, which establishes a framework for the world's first legislated, national, voluntary biodiversity market. How can the effectiveness of these ambitious targets be measured? Natural Capital Accounting (NCA) provides a framework to measure changes in ecosystem condition that is applicable across ecosystems and potentially catalogue effects of restoration interventions to drive investment, improvement to practice, and ultimately, to better protect the Earth's ecosystems. However, the framework has not been tested in this context. In this progressive approach, we populated the leading global NCA framework with ecological data to quantify changes in ecosystem condition after restoration. In principle, NCA is fit for purpose, however, methodological refinements and ecological expertise are needed to unlock its full potential. These tweaks will facilitate adoption and standardisation of reporting as efforts ramp up to meet ambitious global restoration targets.
Journal article
Published 2023
Ecosystem services, 64, 101566
Spatial planning and environmental management are expected to adopt participatory processes. However, the needed spatial data on social values of ecosystem services are limited, especially for marine spatial planning for large, remote coastal areas, and the collection of such information can be time and resource intensive. Crowdsourcing techniques are cost efficient sources of social values data, but must meet the information needs of planners and managers with sufficient confidence. We evaluated the reliability of crowdsourced social values data by assessing the agreement between geotagged photos posted to the social media platform Flickr and data from an online public participation GIS (PPGIS) survey conducted to support marine spatial planning in the Kimberley region of Western Australia.
Flickr could not represent all of the social values mapped in the PPGIS dataset, was notably dominated by scenic values, and under-represented the importance of recreational fishing and Aboriginal cultural values. The Flickr dataset was more affected by accessibility from settlements and transportation infrastructure (roads, boat ramps) and more restricted spatially. Maximum entropy (maxent) distribution models developed to explore the socioecological drivers determining where social values occur also highlighted that Flickr and PPGIS samples provide different perspectives on social values, even after accounting for differences in sampling intensity. The Flickr dataset suggested that the social values occurred under narrower ranges of socioecological conditions, and the PPGIS dataset was more likely to find protected areas to be valued, likely because participants believe protected areas to support those social values, but may not themselves pursue them there.
Flickr and PPGIS crowdsourced datasets provide different perspectives on the spatial distribution of social values for several reasons: They differ in their spatial and demographic biases, as well as their measurement of revealed vs. stated preferences. Flickr is most effective at representing social values that are easily photographed and interpretable in photos, and may not capture some information needs of managers. PPGIS is under greater investigator control but, because stated preferences can be disconnected from actual use of the sites mapped, may be best suited for assessing management preferences and social acceptability. With understanding of the nuances of these datasets, crowdsourced social values data can be applied most appropriately to support successful planning outcomes.
Journal article
Published 2022
Urban Ecosystems
The red fox (Vulpes vulpes) is one of the most adaptable carnivorans, thriving in cities across the globe. We used GPS-tracking of five suburban foxes across high-density residential suburbs of Perth, Western Australia to quantify (1) their habitat selection and (2) home range area. All five foxes showed statistically significant avoidance of residential locations (p < 0.001) and preference for parkland (p < 0.001), with native vegetation reserves, golf courses, and water reserves showing disproportionately greater use. Landuse category also influenced their movements, with foxes moving quickest (i.e., commuting) in proximity to roads and slowest (i.e., foraging) when they were further from roads. Three females had core home ranges (50% autocorrelated-corrected kernel density estimate; AKDEc) averaging 37 ± 20 ha or 95% AKDEc averaging 208 ± 196 ha. One male had a 95 ha core home range and 349 ha 95% AKDEc but the other male covered an area ~ 20 times this: using a 371 ha core home range and 7,368 ha 95% AKDEc. The extensive movement patterns we describe are likely to be common for urban foxes, with half of published home range estimates for urban foxes (principally based on VHF data) excluding data for ‘lost’ individuals or animals that showed ‘excursions’. It is likely that the home range estimates for these urban exploiters have therefore been grossly underestimated to date. Further application of GPS trackers that allow remote download will vastly improve our understanding of habitat preference and exploitation of resources by urban foxes.
Journal article
Livestock guardian dog protection of free-range poultry from the red fox
Published 2022
Animal Production Science, 62, 13, 1290 - 1302
Context: Predation of layer chickens is a major issue for free-range egg producers. Using livestock guardian dogs (LGD) to protect free-ranging poultry is a possible option for producers, although there is little published literature regarding how the dogs protect chickens.
Aims: This case study was conducted at a free-range egg production farm in Western Australia, where red foxes (Vulpes vulpes) were a common predator of chickens prior to introducing Maremma LGD. We investigated LGD responses to experimental cues that might indicate fox incursion (fox urine and calls).
Methods: Four dogs were GPS tracked and monitored using camera traps. Over the first week, experimental fox cues were set out around the paddock boundaries, alternating with ‘non-cue’ experimental control nights. We recorded whether the LGD altered (1) their space use, (2) activity patterns (movement speed), or (3) behaviour in response to these cues. We also recorded (4) distances between LGD from known sightings of foxes.
Key results: The Maremmas appeared to work independently of each other, covering separate areas. There was no significant difference in overnight home range area by experimental fox cue treatment, but there was a significant (P < 0.001) treatment × dog interaction term for distance moved. Three dogs spent most of their time at night around the chicken shelters and generally increased distances moved on experimental fox cue nights. The fourth dog was more bonded to people and did not alter its movements. Paradoxically, dogs rested more and barked less on experimental fox cue nights; however, we recorded foxes on camera traps placed around the chicken shelters on 17 of the 23 nights of monitoring, and the high background activity level of foxes on this property compromised our experimental control (nights without experimental fox cues). The dogs did not move towards known fox sightings.
Conclusions: The Maremmas in this trial closely guarded the chicken shelters rather than maintaining the entire paddock as a predator-exclusion zone.
Implications: Understanding how guardian dogs behave when challenged by potential predators will help increase producers’ confidence in the efficacy of these dogs as a viable method to protect livestock from predation threat.
Journal article
Published 2022
Frontiers in Marine Science, 8, Art. 733841
Understanding species’ distribution patterns and the environmental and ecological interactions that drive them is fundamental for biodiversity conservation. Data deficiency exists in areas that are difficult to access, or where resources are limited. We use a broad-scale, non-targeted dataset to describe dolphin distribution and habitat suitability in remote north Western Australia, where there is a paucity of data to adequately inform species management. From 1,169 opportunistic dolphin sightings obtained from 10 dugong aerial surveys conducted over a four-year period, there were 661 Indo-Pacific bottlenose dolphin (Tursiops aduncus), 191 Australian humpback dolphin (Sousa sahulensis), nine Australian snubfin dolphin (Orcaella heinsohni), 16 Stenella sp., one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), and 290 unidentified dolphin species sightings. Maximum Entropy (MaxEnt) habitat suitability models identified shallow intertidal areas around mainland coast, islands and shoals as important areas for humpback dolphins. In contrast, bottlenose dolphins are more likely to occur further offshore and at greater depths, suggesting niche partitioning between these two sympatric species. Bottlenose dolphin response to sea surface temperature is markedly different between seasons (positive in May; negative in October) and probably influenced by the Leeuwin Current, a prominent oceanographic feature. Our findings support broad marine spatial planning, impact assessment and the design of future surveys, which would benefit from the collection of high-resolution digital images for species identification verification. A substantial proportion of data were removed due to uncertainties resulting from non-targeted observations and this is likely to have reduced model performance. We highlight the importance of considering climatic and seasonal fluctuations in interpreting distribution patterns and species interactions in assuming habitat suitability.
Journal article
Published 2022
Remote Sensing, 14, 8, Article 1827
The Ningaloo Reef, Australia’s longest fringing reef, is uniquely positioned in the NW region of the continent, with clear, oligotrophic waters, relatively low human impacts, and a high level of protection through the World Heritage Site and its marine park status. Non-invasive optical sensors, which seamlessly derive bathymetry and bottom reflectance, are ideally suited for mapping and monitoring shallow reefs such as Ningaloo. Using an existing airborne hyperspectral survey, we developed a new, geomorphic layer for the reef for depths down to 20 m, through an object-oriented classification that combines topography and benthic cover. We demonstrate the classification approach using three focus areas in the northern region of the Muiron Islands, the central part around Point Maud, and Gnaraloo Bay in the south. Topographic mapping combined aspect, slope, and depth into 18 classes and, unsurprisingly, allocated much of the area into shallow, flat lagoons, and highlighted narrow, deeper channels that facilitate water circulation. There were five distinct geomorphic classes of coral-algal mosaics in different topographic settings. Our classifications provide a useful baseline for stratifying ecological field surveys, designing monitoring programmes, and assessing reef resilience from current and future threats.
Journal article
Urban remnant size alters fungal functional groups dispersed by a digging mammal
Published 2021
Biodiversity and Conservation, 30, 3983 - 4003
Digging animals perform many ecosystem functions, including soil turnover and vectoring fungi, particularly mycorrhizal fungi. However, these animals are also susceptible to the impacts of urbanisation, resulting in altered ecosystem processes. Some digging mammals, such as the omnivorous quenda (Isoodon fusciventer), a medium-sized marsupial bandicoot endemic to southwestern Australia, persist in urban landscapes and may play important roles as fungal vectors. This paper examines the fungal community in quenda scats from natural vegetation remnants within a fragmented urban landscape to ask: are quenda acting as vectors for a functionally diverse fungal community?; what fungal functional types are being vectored?; and does remnant size impact fungal species richness and composition vectored by quenda? We sequenced 53 scat samples collected from remnants and found that quenda disperse a functionally diverse fungal community, with 31% of the molecular operational taxonomic units (OTUs) putatively mycorrhizal. Fungal OTU richness was greatest in scats from smaller remnants due to higher mean relative abundance of saprotrophs, pathogens and yeasts. Fungal OTU richness of ectomycorrhizal fungi, critical for plant growth, were found at a higher abundance in larger remnants. Fungal composition was affected by remnant size, type and condition of vegetation, and soil type. Our results indicate that maintaining digging mammal populations within urban landscapes may assist with dispersal of fungi that facilitate fungal-plant interactions, contributing to ecosystem health. These results are important to understand the complex ecological implications of urbanisation, and how remaining mammals are critical in maintaining ecosystem processes within the urban land-use matrix.
Journal article
Assessing the short-term outcomes of a piped water supply intervention in peri-urban Mozambique
Published 2019
Journal of Water, Sanitation and Hygiene for Development, 9, 2, 348 - 355
We use data collected as part of a baseline survey in 2012 and a survey 5 months post-intervention in 2014 to assess the short-term outcomes of a water supply intervention in Ribáuè, Mozambique. This intervention included the rehabilitation and expansion of a piped water system, revitalization of water committees, and creation of and capacity building for small-scale private water enterprises. Quantitative results suggest that the intervention led to an immediate significant increase in the use of piped water supply at the expense of unprotected wells and other non-revenue generating forms of unimproved water supply with more than a 2.5-fold increase in the usage of yard taps and water kiosks/standpipes and a two-fold decrease in the use of unprotected wells. Family water consumption also increased by approximately 40 L/d, and the point-of-use treatment of water nearly tripled. Economic opportunities were generated for business and small enterprise owners due to the new water supply infrastructure, and piped water infrastructure had additional positive effects for both public and private sanitation facilities.
Journal article
An outback oasis: The ecological importance of bilby burrows
Published 2019
Journal of Zoology, 308, 3, 149 - 163
Ecosystem engineers are species that have a role in creating and maintaining certain habitat traits that are important for other species. Burrowing species do this by creating subterranean refugia from predation and thermal extremes, but also providing foraging opportunities through soil movement and by increasing local landscape heterogeneity. In this study, we used camera traps to monitor the burrows of greater bilbies (Macrotis lagotis), a vulnerable Australian marsupial, in an area subject to frequent disturbance by fire. We tested the hypothesis that bilby burrows provide refuge for other species and therefore their presence increases biodiversity. In total, 45 taxa – 22 bird, 16 reptile and 7 mammal taxa – were recorded interacting with 127 burrows across 7 sites. Species richness was greater at burrows compared with vegetation away from burrows, while abundance was no different. There was no difference in species assemblage for bilby burrows that were actively maintained by bilbies compared with abandoned burrows, although there was more activity at bilby maintained burrows. A wildfire allowed us to test the ad hoc hypothesis that the use of bilby burrows was greater when vegetation cover was removed by fire. We recorded significant differences in species assemblage interacting with burrows after fire, although overall species richness and abundance did not change. The response of individual species was variable; for example, burrows provide a refuge for smaller species (such as mice and small reptiles), and may therefore protect them from the effects of fire. Where they persist, bilbies provide an important ecosystem engineering service, as their burrows support a broad range of species. Further reduction in the distribution of the bilby is therefore likely to have a flow-on effect on biodiversity, impacting species that use their burrows for refuge.