Category: Publications

Authors: Ayesha IT Tulloch, Euan G Ritchie, and Don Driscoll

Published in: Austral Ecology

Summary

Feral horses cause extensive ecological harm, including damage to soil, waterways, vegetation, and the carbon cycle, leading to declines in threatened species.

While most Australian states pursue population reduction or removal, NSW’s Kosciuszko Wild Horse Heritage Act mandates retention of horses in parts of Kosciuszko National Park, contradicting scientific consensus and national conservation policies.

Scientific evidence strongly supports complete removal of feral horses from sensitive alpine and subalpine ecosystems, as fencing and local exclusion are insufficient.

Effective protection and restoration of damaged alpine ecosystems requires coordinated management of all invasive species, evidence-based public communication, and legislative support.

Tulloch AIT, Ritchie EG, Driscoll DA (2025) Feral horses and their environmental impacts in the Australian Alps: policy and management priorities. Austral Ecology PDF DOI

Authors: Meg Farmer, Anthony R Rendall, Amy Coetsee, and Euan G Ritchie

Published in: Austral Ecology

Abstract

The global biodiversity extinction crisis is attributed to a series of key threats, with the introduction and impacts of invasive predators considered among the most damaging. Given that effective large-scale lethal control is often not logistically or financially feasible, alternative solutions to promote the persistence of native wildlife most at risk of predation—critical weight range mammals—must be sought. Understanding habitat use and selection of native prey under predation pressure with widespread and common invasive predators, such as feral cats, can quantify habitat elements that may promote survival.

We aimed to determine the movement behaviour of a population of critical weight range mammals persisting in the presence of feral cats. We established a trapping grid across ‘Bluegums’, French Island, in south-eastern Australia to collect morphometric, demographic and movement data by deploying GPS tracking devices on Long-nosed Potoroo (Potorous tridactylus trisulcatus). We used spatially explicit capture–recapture models to generate a potoroo density estimate, and autocorrelated kernel density estimators and dynamic Brownian Bridge Movement Models to examine home range and habitat use. Spatial overlap and habitat selection analyses were used to draw inferences about habitat selection and territoriality.

Potoroos persisted at low densities and had large home ranges (7.3–12.5 ha). Individuals selected for structurally complex habitat and appeared reluctant to move across open areas, potentially in response to greater perceived predation risk. The fine-scale movement data in our study elucidate the extent to which potoroos rely on vegetation structure, suggesting that maintaining habitat cover and connectivity is likely to build resilience and aid potoroos and similar species to co-exist with feral cats.

Given the ongoing threat feral cats pose to biodiversity, our results support the need for maintaining diverse, structurally complex vegetation to build ecosystem resilience to support improved conservation outcomes in the presence of invasive species.

Farmer M, Rendall AR, Coetsee A, Ritchie EG (2025) Habitat selection and movement behaviour of long‐nosed potoroo in the presence of feral cats. Austral Ecology PDF DOI

Authors: Lorenzo Galletta, Anthony R Rendall, Matthew Lefoe, Mary Thorpe, Brit Hides, Ben Holmes, and Euan G Ritchie

Published in: Biological Invasions

Abstract

Biological invasions threaten biodiversity globally. In Australia, introduced and invasive European red foxes (Vulpes vulpes) are a major predator of native wildlife, and are implicated in numerous species extinctions, prompting large-scale fox population control programs. Lethal control—typically via poison (1080) baiting—is common, but the consistency of its efficacy has been questioned, and the desired outcomes are frequently not measured or evaluated.

We aimed to assess the success and impacts of lethal fox control on fox activity, and subsequent effects on a co-occurring, invasive mesopredator (feral cat, Felis catus), and native and invasive prey species. We surveyed three locations in the Wimmera region of Victoria, each experienced a different baiting regime (no baiting, standard systematic baiting, intensified baiting). Camera traps were deployed from April 2021 to August 2023 to determine predator activity alongside non-target herbivores.

Baiting treatment was not associated with differences in fox or cat activity. Nurcoung (no baiting) had the lowest activity of both cats and foxes across the study. Fox activity patterns under standard baiting were higher than intensified baiting.

Our results suggest that fox control might destabilise population dynamics of foxes, potentially facilitating increased activity levels through higher emigration rates from the surrounding agricultural environments.

Our study highlights the critical importance of appropriately monitoring the outcomes of invasive species control programs to ensure the a priori strategic objectives are achieved. To achieve more effective fox population suppression broader, landscape-scale approaches that take a nil-tenure approach are essential.

Galletta L, Rendall AR, Lefoe M, Thorpe M, Hides B, Holmes B, Ritchie EG (2025) Lethal control of semi-arid, red fox populations fails to reduce their abundance but may create increased fox activity. Biological Invasions PDF DOI

Authors: Don A Driscoll, Zac Walker, Desley A Whisson, Euan G Ritchie, Chloe Sato, and Kristina J Macdonald

Published in: Biological Conservation

Abstract

Climate change is driving extreme fires in many ecosystems around the world. There is an urgent need to understand how co-occurring and interacting threats compound megafire impacts on habitats and wildlife.

Using repeated surveys after the 2019–20 Australian megafires, we investigated how the abundance and occupancy of five small mammal and reptile species were influenced by fire severity, fire frequency, feral herbivore impacts, three key habitat components (logs, moss, and weeds), and their interactions.

We found that fire severity, fire frequency, weeds and logs were the most important factors affecting species abundance and occupancy. Increasing fire severity caused precipitous declines of the threatened broad-toothed rat Mastacomys fuscus and glossy grass skink Pseudemoia rawlinsoni. The impact of fire frequency depended on environmental covariates. High fire frequency led to low abundance of the water skink Eulamprus tympanum and M. fuscus if there were no logs. However, both species increased with fire frequency if logs were abundant, implying that logs can ameliorate negative impacts of frequent fire. The threatened Eulamprus kosciuskoi needed fewer than two fires in the past 80 years as well as high moss cover to achieve high abundance. Two threatened alpine skinks, E. kosciuskoi and P. cryodroma, declined with increasing weed cover.

Our study highlights that elucidating interactions between fire and habitat attributes helps to characterise wildfire refuges. Countering the expected impacts of repeated megafires globally will likely require increased protection of refuges from frequent burning, supplementing shelter such as logs where scarce, and mitigating co-occurring and compounding threats.

Driscoll DA, Walker Z, Whisson DA, Ritchie EG, Sato C, Macdonald KJ (2025) Megafire severity, fire frequency and their interactions with habitat affect post-fire responses of small mammal and reptile species. Biological Conservation PDF DOI

Authors: Rachel T Mason, Anthony R Rendall, Robin D Sinclair, Angela JL Pestell, and Euan G Ritchie

Published in: Ecological Solutions and Evidence

Abstract

Understanding how carnivores impact ecological communities is essential for guiding effective management actions and conserving biodiversity. Quantifying predators’ diets, including prey selectivity, allows for the assessment of the relative effects native and invasive predators may have on prey populations.

In Australia, populations of a native, terrestrial apex predator, the dingo Canis dingo/C. familiaris, and introduced and invasive subordinate mesopredators, the European red fox Vulpes vulpes and feral cat Felis catus, co-occur, but there is limited understanding of their relative impacts on native and invasive prey in different ecosystems. To assess the possible effects of dingoes, foxes and cats on prey, we examined their diet and prey selectivity across a ~10,000 km² semi-arid mallee ecosystem.

Using macroscopic scat analysis, we identified strong dietary niche separation. Larger-bodied dingoes primarily consumed large marsupial herbivores, whereas foxes and cats primarily consumed smaller prey, including introduced and native rodents and birds. Foxes had the broadest diet, and the greatest dietary overlap with cats (O_jk = 0.81), compared with dingoes (O_jk = 0.50) or between dingoes and cats (O_jk = 0.36).

Livestock were identified in 2% of dingo and 7% of fox scats. Cats and foxes consumed more than 15 times the volume of small native mammals compared with dingoes, including threatened species such as fat-tailed dunnarts Sminthopsis crassicaudata. Cats and foxes also selectively consumed small mammals relative to their estimated availability and consumed fewer large mammals. In contrast, dingoes consumed fewer birds and more echidnas relative to their availability.

Our results suggest limited intraguild competition within this semi-arid ecosystem, as dingoes are primarily exerting top-down pressure on large herbivores, whereas invasive mesopredators are disproportionately impacting smaller prey, including threatened native mammals.

Our findings suggest that ongoing conservation management of dingoes, red foxes and feral cats must consider the variation in diets, impacts on prey and ecological roles of these different predator species, and avoid indiscriminate lethal control methods. Quantifying actual, rather than assumed, impacts of predators on threatened native species, large herbivores and livestock is essential to achieve effective and integrated ecosystem management.

Mason RT, Rendall AR, Sinclair RD, Pestell AJL, Ritchie EG (2025) What’s on the menu? Examining native apex‐ and invasive meso‐predator diets to understand impacts on ecosystems. Ecological Solutions and Evidence PDF DOI

Authors: Rebecca K Gibson, Don A Driscoll, Kristina J Macdonald, Grant J Williamson, Rachael H Nolan, Tim S Doherty, Dale G Nimmo, Euan G Ritchie, Mark Tozer, Liz Tasker, Aaron Greenville, Adam Roff, Alex Callen, Alex Maisey, Alexandria Thomsen, Alfonsina Arriaga-Jimenez, Alison Foster, Alison Hewitt, Amy-Marie Gilpin, Andrew Denham, Andrew Stauber, Berin Mackenzie, Brad Law, Brad Murray, Brian Hawkins, Bridget Roberts, Chad T Beranek, Chris Dickman, Chris J Jolly, Chris McLean, Chris Reid, Craig Dunne, David Hancock, David Keith, Elise Pendall, Elise Verhoeven, Emma Cook, Emma Spencer, Felicity Grant, Frank Koehler, George Madani, Glenda Wardle, Grant Linley, James M Cook, Jedda Lemmon, John Gould, Jonathan K Webb, Joshua Lee, Julia Rayment, Karen Marsh, Kaya Klop-Toker, Laura Schweickle, Mark Ooi, Matthew Beitzel, Matthias Boer, Michael Hewins, Michael Mahony, Mikayla Green, Mike Letnic, Murraya Lane, Oliver W Kelly, Owen Price, Renee Brawata, Rohan Bilney, Ross Crates, Ryan R Witt, Ryan Shofner, Sally A Power, Samantha L Wallace, Sarah E Stock, Shelby A Ryan, Stephanie Pulsford, Thomas Newsome, Tom Le Breton, Vanessa Allen, Vivianna Miritis, and Zac Walker

Published in: Global Ecology and Biogeography

Abstract

Aim: To compare field-based evidence of plant and animal responses to fire with remotely sensed signals of fire heterogeneity and post-fire biomass recovery.

Location: South-eastern Australia; New South Wales.

Time period: 2019–2022.

Major taxa studied: A total of 982 species of plants and animals, in eight taxonomic groups: amphibians, birds, fish, insects, mammals, molluscs, plants and reptiles.

Methods: We collated 545,223 plant and animal response records from 47 field surveys of 4613 sites that focussed on areas burnt in 2019–2020. For each site, we calculated remotely sensed signals of fire heterogeneity and post-fire biomass recovery, including the delayed recovery index. Meta-regression analyses were conducted separately for species that declined after fire (negative effect sizes) and species that increased after fire (positive effect sizes) for each buffer size (250 m, 500 m, 1 km, 1.5 km, 2 km and 2.5 km radius).

Results: We found that species exposed to homogenous high-severity fire (i.e., low fire heterogeneity) were more likely to exhibit decreased abundance/occurrence or inhibited recovery. Areas with delayed recovery of biomass also had significant negative on-ground responses, with lower abundance or occurrence in areas where biomass recovery was slower.

Main conclusions: The fire heterogeneity index and the delayed recovery index are suitable for inclusion in monitoring and reporting systems for tracking relative measures over time, particularly when field survey data is not available at the landscape scales required to support reporting and management decisions. Locations with remotely sensed signals of delayed recovery should be prioritised for protection against further disturbances that may interfere with the recovery process. Research attention must next focus on how cumulative fire heterogeneity patterns of successive fires affect the post-fire recovery dynamics to further inform the application of remote sensing indicators as management tools for biodiversity conservation.

Gibson RK, Driscoll DA, Macdonald KJ, Williamson GJ, Nolan RH, Doherty TS, Nimmo DG, Ritchie EG, Tozer M, Tasker L, Greenville A, Roff A, Callen A, Maisey A, Thomsen A, Arriaga‐Jimenez A, Foster A, Hewitt A, Gilpin A, Denham A, Stauber A, Mackenzie B, Law B, Murray B, Hawkins B, Roberts B, Beranek CT, Dickman C, Jolly CJ, McLean C, Reid C, Dunne C, Hancock D, Keith D, Pendall E, Verhoeven E, Cook E, Spencer E, Grant F, Koehler F, Madani G, Wardle G, Linley G, Cook JM, Lemmon J, Gould J, Webb JK, Lee J, Rayment J, Marsh K, Klop‐Toker K, Schweickle L, Ooi M, Beitzel M, Boer M, Hewins M, Mahony M, Green M, Letnic M, Lane M, Kelly OW, Price O, Brawata R, Bilney R, Crates R, Witt RR, Shofner R, Power SA, Wallace SL, Stock SE, Ryan SA, Pulsford S, Newsome T, Le Breton T, Allen V, Miritis V, Walker Z (2025) Remotely sensed fire heterogeneity and biomass recovery predicts empirical biodiversity responses. Global Ecology and Biogeography PDF DOI

Authors: Grant D Linley, Chris J Jolly, Tim S Doherty, William L Geary, Dolors Armenteras, Claire M Belcher, Rebecca Bliege Bird, Andrea Duane, Michael-Shawn Fletcher, Melisa A Giorgis, Angie Haslem, Gavin M Jones, Luke T Kelly, Calvin K F Lee, Rachael H Nolan, Catherine L Parr, Juli G Pausas, Jodi N Price, Adrián Regos, Euan G Ritchie, Julien Ruffault, Grant J Williamson, Qianhan Wu, and Dale G Nimmo

Published in: Global Ecology and Biogeography

Abstract

Aim: The term ‘megafire’ is increasingly used to describe large fires worldwide. We proposed a size-based definition of megafire—fires exceeding 10,000 ha arising from single or multiple related ignition events. A recent perspective in Global Ecology and Biogeography argues against a size-based definition of megafire and suggest that the term is too emotive for scientific use. We highlight that many scientific terms originate from common terms. These terms are often defined once they enter the scientific lexicon, enhancing both scientific understanding and public communication. We argue that standardised definitions facilitate better prediction, preparation, and management of fire events.

Location: Worldwide.

Time period: 2022–2023.

Methods: We conducted an updated structured review of the term ‘megafire’ and its use and definition in the peer-reviewed scientific literature, collating definitions and descriptions and identifying the criteria frequently invoked to define the term.

Results: We demonstrate an increase in the use of ‘megafire’ in the scientific literature since our original definition in 2022, with many studies adopting the > 10,000 ha size-based criterion.

Main conclusions: We contend that abandoning the term is neither practical, possible, nor beneficial. Instead, consistent usage underpinned by clear definitions is essential. Adopting a clear, size-based definition of megafire strengthens clarity and comparability across research and management practices globally. Precision in terminology is crucial for advancing research, improving communication, and informing effective fire management and policy.

Linley GD, Jolly CJ, Doherty TS, Geary WL, Armenteras D, Belcher CM, Bliege Bird R, Duane A, Fletcher M, Giorgis MA, Haslem A, Jones GM, Kelly LT, Lee CKF, Nolan RH, Parr CL, Pausas JG, Price JN, Regos A, Ritchie EG, Ruffault J, Williamson GJ, Wu Q, Nimmo DG (2025) ‘Megafire’ — you may not like it, but you cannot avoid it. Global Ecology and Biogeography PDF DOI

Authors: Angela JL Pestell, Anthony R Rendall, Robin D Sinclair, Euan G Ritchie, Duc T Nguyen, Dean M Corva, Anne C Eichholtzer, Abbas Z Kouzani, and Don A Driscoll

Published in: Ecosphere

Abstract

Limited data on species’ distributions are common for small animals, impeding conservation and management. Small animals, especially ectothermic taxa, are often difficult to detect, and therefore require increased time and resources to survey effectively. The rise of conservation technology has enabled researchers to monitor animals in a range of ecosystems and for longer periods than traditional methods (e.g., live trapping), increasing the quality of data and the cost-effectiveness of wildlife monitoring practices.

We used DeakinCams, custom-built smart camera traps, to address three aims:

1. To survey small animals, including ectotherms, and evaluate the performance of a customized computer vision object detector trained on the SAWIT dataset for automating object classification.
2. At the same field sites and using commercially available camera traps, we evaluated how well MegaDetector—a freely available object detection model—detected images containing animals.
3. We evaluated the complementarity of these two different approaches to wildlife monitoring.

We collected 85,870 videos from the DeakinCams and 50,888 images from the commercial cameras. For object detection with DeakinCams data, SAWIT yielded 98% precision but 47% recall, and for species classification, SAWIT performance varied by taxa, with 0% precision and recall for birds and 26% precision and 14% recall for spiders. For object detections with camera trap images, MegaDetector returned 99% precision and 98% recall. We found that only the DeakinCams detected nocturnal ectotherms and invertebrates.

Making use of more diverse datasets for training models as well as advances in machine learning will likely improve the performance of models like YOLO in novel environments.

Our results support the need for continued cross-disciplinary collaboration to ensure that large environmental datasets are available to train and test existing and emerging machine learning algorithms.

Pestell AJL, Rendall AR, Sinclair RD, Ritchie EG, Nguyen DT, Corva DM, Eichholtzer AC, Kouzani AZ, Driscoll DA (2025) Smart camera traps and computer vision improve detections of small fauna. Ecosphere PDF DOI

Authors: Stephanie K Courtney Jones, Luke S O’Loughlin, Danswell Starrs, Jacinta E Humphrey, Stephanie A Pulsford, Hugh Allan, Matt Beitzel, Kym Birgen, Suzi Bond, Jenny Bounds, Deborah Bower, Renee Brawata, Ben Broadhurst, Emma Carlson, Simon Clulow, Saul Cunningham, Luke Dunn, Lisa Evans, Bruno Ferronato, Donald B Fletcher, Arthur Georges, Amy-Marie Gilpin, Mark A Hall, Brian Hawkins, Anke Maria Hoeffer, Brett Howland, Damian C Lettoof, Mark Lintermans, Michelle Littlefair, Tanya Latty, Tyrone H Lavery, Zohara Lucas, George Madani, Kim Maute, Richard NC Milner, Eric J Nordberg, Thea O’Loughlin, Woo O’Reilly, Megan O’Shea, Laura Rayner, Euan G Ritchie, Natasha M Robinson, Stephan D Sarre, Manu E Saunders, Ben C Scheele, Julian Seddon, Rob Speirs, Ricky Spencer, Ingrid Stirnemann, David M Watson, Belinda A Wilson, Peter J Unmack, Yuying Zhao, and Melissa A Snape

Published in: Biological Conservation

Abstract

Urban planning which enhances native biodiversity in and around cities is needed to address the impacts of urbanisation and conserve urban biodiversity. The “Biodiversity Sensitive Urban Design” (BSUD) framework incorporates ecological knowledge into urban planning to achieve positive biodiversity outcomes through improved urban design and infrastructure development. BSUD includes principles to direct strategic design and placement of connected wildlife habitat. However, effective BSUD implementation requires defining and quantifying the landscape-scale habitat connectivity needs of a range of taxon groups within urban contexts.

The aim of our study was to use expert elicitation to address these gaps in landscape-scale habitat connectivity currently limiting the capacity of urban planning. We estimated habitat connectivity needs for seven representative taxon groups in urban environments, including ideal habitat, habitat constraints, barriers to movement, and movement thresholds that determine habitat connectivity.

In using expert elicitation to quantify habitat connectivity requirements for urban biodiversity, our study provides insights on both the usefulness of expert elicitation to inform urban habitat connectivity planning generally, and the functional habitat connectivity requirements of our focal taxon groups specifically. Overall, we consider our expert-derived estimates of connected habitat to be a highly useful set of baseline data for habitat and connectivity modelling and urban planning for a range of taxon groups.

Courtney Jones SK, O’Loughlin LS, Starrs D, Humphrey JE, Pulsford SA, Allan H, Beitzel M, Birgen K, Bond S, Bounds J, Bower D, Brawata R, Broadhurst B, Carlson E, Clulow S, Cunningham S, Dunn L, Evans L, Ferronato B, Fletcher DB, Georges A, Gilpin A-M, Hall MA, Hawkins B, Hoeffer AM, Howland B, Lettoof DC, Lintermans M, Littlefair M, Latty T, Lavery TH, Lucas Z, Madani G, Maute K, Milner RNC, Nordberg EJ, O’Loughlin T, O’Reilly W, O’Shea M, Rayner L, Ritchie EG, Robinson NM, Sarre SD, Saunders ME, Scheele BC, Seddon J, Speirs R, Spencer R, Stirnemann I, Watson DM, Wilson BA, Unmack PJ, Zhao Y, Snape MA (2025) Quantifying taxon-specific habitat connectivity requirements of urban wildlife using structured expert judgement. Biological Conservation PDF DOI