Category Archives: Publications

Reptiles as food: predation of Australian reptiles by introduced red foxes compounds and complements predation by cats

Authors: Alyson M Stobo-Wilson, Brett P Murphy, Sarah M Legge, David G Chapple, Heather M Crawford, Stuart J Dawson, Chris R Dickman, Tim S Doherty, Patricia A Fleming, Matthew Gentle, Thomas M Newsome, Russell Palmer, Matthew W Rees, Euan G Ritchie, James Speed, John-Michael Stuart, Eilysh Thompson, Jeff Turpin, and and John C Z Woinarski

Published in: Wildlife Research

Abstract

Context: Invasive species are a major cause of biodiversity loss across much of the world, and a key threat to Australia’s diverse reptile fauna. There has been no previous comprehensive analysis of the potential impact of the introduced European red fox, Vulpes vulpes, on Australian reptiles.

Aims: We seek to provide an inventory of all Australian reptile species known to be consumed by the fox, and identify characteristics of squamate species associated with such predation. We also compare these tallies and characteristics with reptile species known to be consumed by the domestic cat, Felis catus, to examine whether predation by these two introduced species is compounded (i.e. affecting much the same set of species) or complementary (affecting different groups of species).

Methods: We collated records of Australian reptiles consumed by foxes in Australia, with most records deriving from fox dietary studies (tallying >35 000 samples). We modelled presence or absence of fox predation records against a set of biological and other traits, and population trends, for squamate species.

Key results: In total, 108 reptile species (~11% of Australia’s terrestrial reptile fauna) have been recorded as consumed by foxes, fewer than that reported for cats (263 species). Eighty-six species have been reported to be eaten by both predators. More Australian turtle species have been reported as consumed by foxes than by cats, including many that suffer high levels of predation on egg clutches. Twenty threatened reptile species have been reported as consumed by foxes, and 15 by cats. Squamate species consumed by foxes are more likely to be undergoing population decline than those not known to be consumed by foxes. The likelihood of predation by foxes increased with squamate species’ adult body mass, in contrast to the relationship for predation by cats, which peaked at ~217 g. Foxes, but not cats, were also less likely to consume venomous snakes.

Conclusions: The two introduced, and now widespread, predators have both compounding and complementary impacts on the Australian reptile fauna.

Implications: Enhanced and integrated management of the two introduced predators is likely to provide substantial conservation benefits to much of the Australian reptile fauna.

Stobo-Wilson AM, Murphy BP, Legge SM, Chapple DG, Crawford HM, Dawson SJ, Dickman CR, Doherty TS, Fleming PA, Gentle M, Newsome TM, Palmer R, Rees MW, Ritchie EG, Speed J, Stuart J-M, Thompson E, Turpin J, Woinarski JCZ (2021) Reptiles as food: predation of Australian reptiles by introduced red foxes compounds and complements predation by cats. Wildlife Research PDF DOI

Diet of the introduced red fox Vulpes vulpes in Australia: analysis of temporal and spatial patterns

Authors: Patricia A Fleming, Heather M Crawford, Alyson M Stobo-Wilson, Stuart J Dawson, Christopher R Dickman, Shannon J Dundas, Matthew N Gentle, Thomas M Newsome, Julie O’Connor, Russell Palmer, Joanna Riley, Euan G Ritchie, James Speed, Glen Saunders, John-Michael D Stuart, Eilysh Thompson, Je! M Turpin, John C Z Woinarski

Published in: Mammal Review

The red fox Vulpes vulpes is one of the world’s most widespread carnivores. A key to its success has been its broad, opportunistic diet. The fox was introduced to Australia about 150 years ago, and within 30 years of its introduction was already recognised as a threat to livestock and native wildlife.

We reviewed 85 fox diet studies (totalling 31693 samples) from throughout the species’ geographic range within Australia. Mammals were a major component of fox diet, being present in 70 ± 19% of samples across n = 160 locations. Invertebrates (38 ± 26% n = 130) and plant material (26 ± 25% n = 123) were also both staple foods and often the dominant food category recorded. Birds (13 ± 11% n = 137) and reptiles (10 ± 15% n = 132) were also commonly reported, while frogs were scarcely represented (1.6 ± 3.6% n = 111) in fox diet studies.

Biogeographical differences reveal factors that likely determine prey availability. Diet composition varied with ecosystem, level of vegetation clearing and condition, and climate zone.

Sample type (i.e. stomach versus scat samples) also significantly influenced reporting of diet composition. Livestock and frogs were underrepresented in records based on analysis of scats, whereas small mammals (native rodents, dasyurid marsupials, and bats) were more likely to be recorded in studies of scats than in studies of stomach contents.

Diet varied seasonally, reflecting activity patterns of prey species and food availability. This synthesis also captures temporal shifts in fox diet over 70 years (1951–2020), as foxes have switched to consuming more native species in the wake of successful broadscale biological control of the invasive European rabbit Oryctolagus cuniculus.

Diet analyses, such as those summarised in this review, capture the evidence required to motivate for greater control of foxes in Australia. This synthesis also highlights the importance of integrated pest species management to meet biodiversity conservation outcomes.

Fleming PA, Crawford HM, Stobo‐Wilson AM, Dawson SJ, Dickman CR, Dundas SJ, Gentle MN, Newsome TM, O’Connor J, Palmer R, Riley J, Ritchie EG, Speed J, Saunders G, Stuart JD, Thompson E, Turpin JM, Woinarski JCZ (2021) Diet of the introduced red fox Vulpes vulpes in Australia: analysis of temporal and spatial patterns. Mammal Review PDF DOI

Fire and its interactions with other drivers shape a distinctive, semi-arid ‘mallee’ ecosystem

Authors: Michael F Clarke, Luke T Kelly, Sarah C Avitabile, Joe Benshemesh, Kate E Callister, Don A Driscoll, Peter Ewin, Katherine Giljohann, Angie Haslem, Sally A Kenny, Steve Leonard, Euan G Ritchie, Dale G Nimmo, Natasha Schedvin, Kathryn Schneider, Simon J Watson, Martin Westbrooke, Matt White, Michael A Wouters, and Andrew F Bennett

Published in: Frontiers in Ecology and Evolution

Abstract

Fire shapes ecosystems globally, including semi-arid ecosystems. In Australia, semi-arid ‘mallee’ ecosystems occur primarily across the southern part of the continent, forming an interface between the arid interior and temperate south. Mallee vegetation is characterized by short, multi-stemmed eucalypts that grow from a basal lignotuber. Fire shapes the structure and functioning of mallee ecosystems.

Using the Murray Mallee region in south-eastern Australia as a case study, we examine the characteristics and role of fire, the consequences for biota, and the interaction of fire with other drivers.

Wildfires in mallee ecosystems typically are large (1000s ha), burn with high severity, commonly cause top-kill of eucalypts, and create coarse-grained mosaics at a regional scale. Wildfires can occur in late spring and summer in both dry and wet years. Recovery of plant and animal communities is predictable and slow, with regeneration of eucalypts and many habitat components extending over decades. Time since the last fire strongly influences the distribution and abundance of many species and the structure of plant and animal communities.

Animal species display a discrete set of generalized responses to time since fire. Systematic field studies and modeling are beginning to reveal how spatial variation in fire regimes (‘pyrodiversity’) at different scales shapes biodiversity. Pyrodiversity includes variation in the extent of post-fire habitats, the diversity of post-fire age-classes and their configuration.

At regional scales, a desirable mix of fire histories for biodiversity conservation includes a combination of early, mid and late post-fire age-classes, weighted toward later seral stages that provide critical habitat for threatened species. Biodiversity is also influenced by interactions between fire and other drivers, including land clearing, rainfall, herbivory and predation.

Extensive clearing for agriculture has altered the nature and impact of fire, and facilitated invasion by pest species that modify fuels, fire regimes and post-fire recovery.

Given the natural and anthropogenic drivers of fire and the consequences of their interactions, we highlight opportunities for conserving mallee ecosystems. These include learning from and fostering Indigenous knowledge of fire, implementing actions that consider synergies between fire and other processes, and strategic monitoring of fire, biodiversity and other drivers to guide place-based, adaptive management under climate change.

Clarke MF, Kelly LT, Avitabile SC, Benshemesh J, Callister KE, Driscoll DA, Ewin P, Giljohann K, Haslem A, Kenny SA, Leonard S, Ritchie EG, Nimmo DG, Schedvin N, Schneider K, Watson SJ, Westbrooke M, White M, Wouters MA, Bennett AF (2021) Fire and its interactions with other drivers shape a distinctive, semi-arid ‘mallee’ ecosystem, Frontiers in Ecology and Evolution PDF DOI

Assessing the benefits of integrated introduced predator management for recovery of native predators

Authors: Tim S Jessop, Ben Holmes, Arvel Sendjojo, Mary O Thorpe, and Euan G Ritchie

Published in: Restoration Ecology

Abstract

Increasingly threatened species and their habitats require multiple successful management actions to ensure persistence. Introduced predator exclusion and suppression programs are key conservation actions used to retain or restore Australian ecosystems. Nevertheless, few direct comparisons are made to ascertain the individual and combined efficacy of multiple introduced predator conservation actions to benefit biodiversity. When colocated, both management actions could generate additive conservation benefits that greatly assist the recovery or persistence of threatened native species.

Varanid lizards are key functional components in Australian predator guilds and could benefit, via ecological release, when introduced predator management actions are successful. Here we tested the effects of a colocated predator-exclusion fence and lethal fox baiting on varanid site occupancy in a semiarid protected area.

Varanid site occupancy was higher at sites inside (Ψ = 0.90 ± 0.26) compared to sites outside (Ψ = 0.61 ± 0.28) the introduced predator-proof fenced enclosure. There was only weak evidence of increased varanid site occupancy at fox baited sites (Ψ = 0.037 ± 0.024) compared to nonfox baited (Ψ = 0.00) sites.

Overall, colocated introduced predator management actions achieved some additive benefits via possible spillover fencing effects for native mesopredator populations. However, most potential benefits to varanid populations outside of the predator-proof fenced enclosure were absent due to unsuccessful lethal-baiting effects on fox populations. The predator-proof fenced enclosure nevertheless provides important habitat refugia for future source populations for reintroduction once adjacent protected areas become suitable.

Jessop TS, Holmes B, Sendjojo A, Thorpe MO, Ritchie EG (2021) Assessing the benefits of integrated introduced predator management for recovery of native predators. Restoration Ecology PDF DOI

A rocky heart in a spinifex sea: occurrence of an endangered marsupial predator is multiscale dependent in naturally fragmented landscapes

Authors: Harry A Moore, Damian R Michael, Euan G Ritchie, Judy A Dunlop, Leonie E Valentine, Richard J Hobbs, and Dale G Nimmo

Published in: Landscape Ecology

Abstract

Context

Research on the impacts of anthropogenic habitat fragmentation has dominated landscape ecology for decades, yet our understanding of what drives species’ distributions in naturally fragmented landscapes remains limited.

Objectives

We aimed to

  1. determine whether rocky patches embedded within a ‘matrix’ of fire prone grasslands act as naturally fragmented landscapes for an endangered marsupial predator, the northern quoll (Dasyurus hallucatus), and
  2. reveal the extent to which within-patch, patch, landscape variables, and matrix condition drive the occurrence of northern quolls.

Methods

We deployed remote sensing cameras for a total of 200 nights, at 230 sites spanning rocky and grassland habitats across 6000 km2 of the Pilbara bioregion of Western Australia. We examined the influence of within-patch, patch, landscape variables, and matrix condition on northern quolls using Generalised Linear Mixed Models.

Results

We found strong evidence that northern quoll habitat is naturally fragmented, observing higher occurrence and abundance of quolls in rocky patches than the surrounding grassland matrix. Within rocky patches, quolls were more likely to use patches with higher vegetation cover and den availability (within-patch), lower amounts of edge habitat relative to patch area (patch), and larger amounts of surrounding rocky habitat (landscape). When quolls entered the matrix, they tended to remain in areas with high vegetation cover, close to rocky patches.

Conclusions

Species occurrence in naturally fragmented landscapes is influenced by factors operating at multiple scales. Rocky habitats are naturally fragmented and vital to the conservation of a range of taxa around the world, including the northern quoll.

Moore HA, Michael DR, Ritchie EG, Dunlop JA, Valentine LE, Hobbs RJ, Nimmo DG (2021) A rocky heart in a spinifex sea: occurrence of an endangered marsupial predator is multiscale dependent in naturally fragmented landscapes. Landscape Ecology PDF DOI

Combating ecosystem collapse from the tropics to the Antarctic

Authors: Dana M Bergstrom, Barbara C Wienecke, John van den Hoff, Lesley Hughes, David B Lindenmayer Tracy D Ainsworth, Christopher M Baker, Lucie Bland, David M J S Bowman, Shaun T Brooks, Josep G Canadell, Andrew J Constable, Katherine A Dafforn, Michael H Depledge, Catherine R Dickson Norman C Duke, Kate J Helmstedt, Andrés Holz, Craig R Johnson, Melodie A McGeoch, Jessica Melbourne‐Thomas, Rachel Morgain, Emily Nicholson, Suzanne M Prober, Ben Raymond, Euan G Ritchie, Sharon A Robinson, Katinka X Ruthrof, Samantha A Setterfield, Carla M Sgrò, Jonathan S Stark, Toby Travers, Rowan Trebilco, Delphi F L Ward, Glenda M Wardle, Kristen J Williams, Phillip J Zylstra, and Justine D Shaw

Published in: Global Change Biology

Abstract

Globally, collapse of ecosystems—potentially irreversible change to ecosystem structure, composition and function—imperils biodiversity, human health and well‐being.

We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km², from Australia’s coral reefs to terrestrial Antarctica.

Pressures from global climate change and regional human impacts, occurring as chronic ‘presses’ and/or acute ‘pulses’, drive ecosystem collapse. Ecosystem responses to 5–17 pressures were categorised as four collapse profiles—abrupt, smooth, stepped and fluctuating.

The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action.

We present a three‐step assessment and management framework (3As Pathway Awareness, Anticipation and Action) to aid strategic and effective mitigation to alleviate further degradation to help secure our future.

Bergstrom DM, Wienecke BC, Hoff J, Hughes L, Lindenmayer DB, Ainsworth TD, Baker CM, Bland L, Bowman DMJS, Brooks ST, Canadell JG, Constable AJ, Dafforn KA, Depledge MH, Dickson CR, Duke NC, Helmstedt KJ, Holz A, Johnson CR, McGeoch MA, Melbourne‐Thomas J, Morgain R, Nicholson E, Prober SM, Raymond B, Ritchie EG, Robinson SA, Ruthrof KX, Setterfield SA, Sgrò CM, Stark JS, Travers T, Trebilco R, Ward DFL, Wardle GM, Williams KJ, Zylstra PJ, Shaw JD (2021) Combating ecosystem collapse from the tropics to the Antarctic. Global Change Biology PDF DOI

Broadening the ecology of fear: non-lethal effects arise from diverse responses to predation and parasitism

Authors: David R Daversa, Ryan F Hechinger, Elizabeth Madin, Andy Fenton, Anthony I Dell, Euan G Ritchie, Jason Rohr, Volker HW Rudolf, and Kevin D Lafferty

Published in: Proceedings of the Royal Society B: Biological Sciences

Abstract

Research on the ‘ecology of fear’ posits that defensive prey responses to avoid predation can cause non-lethal effects across ecological scales. Parasites also elicit defensive responses in hosts with associated non-lethal effects, which raises the longstanding, yet unresolved question of how non-lethal effects of parasites compare with those of predators.

We developed a framework for systematically answering this question for all types of predator–prey and host–parasite systems. Our framework reveals likely differences in non-lethal effects not only between predators and parasites, but also between different types of predators and parasites.

Trait responses should be strongest towards predators, parasitoids and parasitic castrators, but more numerous and perhaps more frequent for parasites than for predators. In a case study of larval amphibians, whose trait responses to both predators and parasites have been relatively well studied, existing data indicate that individuals generally respond more strongly and proactively to short-term predation risks than to parasitism.

Apart from studies using amphibians, there have been few direct comparisons of responses to predation and parasitism, and none have incorporated responses to micropredators, parasitoids or parasitic castrators, or examined their long-term consequences.

Addressing these and other data gaps highlighted by our framework can advance the field towards understanding how non-lethal effects impact prey/host population dynamics and shape food webs that contain multiple predator and parasite species.

Daversa DR, Hechinger RF, Madin E, Fenton A, Dell AI, Ritchie EG, Rohr J, Rudolf VHW, Lafferty KD (2021) Broadening the ecology of fear: non-lethal effects arise from diverse responses to predation and parasitism. Proceedings of the Royal Society B: Biological Sciences PDF DOI

Evaluating participatory modeling methods for co‐creating pathways to sustainability

Authors: E A Moallemi, F J de Haan, M Hadjikakou, S Khatami, S Malekpour, A Smajgl, M Stafford Smith, A Voinov, R Bandari, P Lamichhane, K K Miller, E Nicholson, W Novalia, E G Ritchie, A M Rojas, M A Shaikh, K Szetey, and B A Bryan

Published in: Earth’s Future

The achievement of global sustainability agendas, such as the Sustainable Development Goals, relies on transformational change across society, economy, and environment that are co‐created in a transdisciplinary exercise by all stakeholders. Within this context, environmental and societal change is increasingly understood and represented via participatory modeling for genuine engagement with multiple collaborators in the modeling process. Despite the diversity of participatory modeling methods to promote engagement and co‐creation, it remains uncertain what the extent and modes of participation are in different contexts, and how to select the suitable methods to use in a given situation.

Based on a review of available methods and specification of potential contextual requirements, we propose a unifying framework to guide how collaborators of different backgrounds can work together and evaluate the suitability of participatory modeling methods for co‐creating sustainability pathways.

The evaluation of method suitability promises the integration of concepts and approaches necessary to address the complexities of problems at hand while ensuring robust methodologies based on well‐tested evidence and negotiated among participants. Using two illustrative case studies, we demonstrate how to explore and evaluate the choice of methods for participatory modeling in varying contexts.

The insights gained can inform creative participatory approaches to pathway development through tailored combinations of methods that best serve the specific sustainability context of particular case studies.

Moallemi EA, de Haan FJ, Hadjikakou M, Khatami S, Malekpour S, Smajgl A, Smith MS, Voinov A, Bandari R, Lamichhane P, Miller KK, Nicholson E, Novalia W, Ritchie EG, Rojas AM, Shaikh MA, Szetey K, Bryan BA (2021) Evaluating Participatory Modeling Methods for Co‐creating Pathways to Sustainability. Earth’s Future PDF DOI

Training future generations to deliver evidence‐based conservation and ecosystem management

Authors: Harriet Downey, Tatsuya Amano, Marc Cadotte, Carly N Cook, Steven J Cooke, Neal R Haddaway, Julia P G Jones, Nick Littlewood, Jessica C Walsh, Mark I Abrahams, Gilbert Adum,, Munemitsu Akasaka, Jose A Alves, Rachael E Antwis, Eduardo C Arellano, Jan Axmacher, Holly Barclay, Lesley Batty, Ana Benítez‐López, Joseph R Bennett, Maureen J Berg, Sandro Bertolino, Duan Biggs, Friederike C Bolam Tim Bray, Barry W Brook, Joseph W Bull, Zuzana Burivalova, Mar Cabeza, Alienor L M Chauvenet Alec P Christie, Lorna Cole, Alison J Cotton, Sam Cotton, Sara A O Cousins, Dylan Craven, Will Cresswell, Jeremy J Cusack, Sarah E Dalrymple, Zoe G Davies, Anita Diaz, Jennifer A Dodd, Adam Felton, Erica Fleishman, Charlie J Gardner, Ruth Garside, Arash Ghoddousi, James J Gilroy, David A Gill, Jennifer A Gill, Louise Glew, Matthew J Grainger, Amelia A Grass, Stephanie Greshon, Jamie Gundry Tom Hart, Charlotte R Hopkins, Caroline Howe, Arlyne Johnson, Kelly W Jones, Neil R Jordan, Taku Kadoya, Daphne Kerhoas, Julia Koricheva, Tien Ming Lee, Szabolcs Lengyel, Stuart W Livingstone Ashley Lyons, Gráinne McCabe, Jonathan Millett, Chloë Montes Strevens, Adam Moolna, Hannah L Mossman, Nibedita Mukherjee, Andrés Muñoz‐Sáez, Nuno Negrões, Olivia Norfolk, Takeshi Osawa Sarah Papworth, Kirsty J Park, Jérôme Pellet, Andrea D Phillott, Joshua M Plotnik, Dolly Priatna Alejandra G Ramos, Nicola Randall, Rob M Richards, Euan G Ritchie, David L Roberts, Ricardo Rocha Jon Paul Rodríguez, Roy Sanderson, Takehiro Sasaki, Sini Savilaakso, Carl Sayer, Cagan Sekercioglu Masayuki Senzaki, Grania Smith, Robert J Smith, Masashi Soga, Carl D Soulsbury, Mark D Steer, Gavin Stewart, E F Strange, Andrew J Suggitt, Ralph R J Thompson, Stewart Thompson, Ian Thornhill, R J Trevelyan, Hope O Usieta, Oscar Venter, Amanda D Webber, Rachel L White, Mark J Whittingham Andrew Wilby, Richard W Yarnell, Veronica Zamora, William J Sutherland

Published in: Ecological Solutions and Evidence

Abstract

To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence‐based decisions and of the value of evidence synthesis.

If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an effective contribution to conservation practice.

To help overcome this problem, we have created open access online teaching materials in multiple languages that are stored in Applied Ecology Resources. So far, 117 educators from 23 countries have acknowledged the importance of this and are already teaching or about to teach skills in appraising or using evidence in conservation decision‐making. This includes 145 undergraduate, postgraduate or professional development courses.

We call for wider teaching of the tools and skills that facilitate evidence‐based conservation and also suggest that providing online teaching materials in multiple languages could be beneficial for improving global understanding of other subject areas.

Downey H, Amano T, Cadotte M, Cook CN, Cooke SJ, Haddaway NR, Jones JPG, Littlewood N, Walsh JC, Abrahams MI, Adum G, Akasaka M, Alves JA, Antwis RE, Arellano EC, Axmacher J, Barclay H, Batty L, Benítez‐López A, Bennett JR, Berg MJ, Bertolino S, Biggs D, Bolam FC, Bray T, Brook BW, Bull JW, Burivalova Z, Cabeza M, Chauvenet ALM, Christie AP, Cole L, Cotton AJ, Cotton S, Cousins SAO, Craven D, Cresswell W, Cusack JJ, Dalrymple SE, Davies ZG, Diaz A, Dodd JA, Felton A, Fleishman E, Gardner CJ, Garside R, Ghoddousi A, Gilroy JJ, Gill DA, Gill JA, Glew L, Grainger MJ, Grass AA, Greshon S, Gundry J, Hart T, Hopkins CR, Howe C, Johnson A, Jones KW, Jordan NR, Kadoya T, Kerhoas D, Koricheva J, Lee TM, Lengyel S, Livingstone SW, Lyons A, McCabe G, Millett J, Strevens CM, Moolna A, Mossman HL, Mukherjee N, Muñoz‐Sáez A, Negrões N, Norfolk O, Osawa T, Papworth S, Park KJ, Pellet J, Phillott AD, Plotnik JM, Priatna D, Ramos AG, Randall N, Richards RM, Ritchie EG, Roberts DL, Rocha R, Rodríguez JP, Sanderson R, Sasaki T, Savilaakso S, Sayer C, Sekercioglu C, Senzaki M, Smith G, Smith RJ, Soga M, Soulsbury CD, Steer MD, Stewart G, Strange EF, Suggitt AJ, Thompson RRJ, Thompson S, Thornhill I, Trevelyan RJ, Usieta HO, Venter O, Webber AD, White RL, Whittingham MJ, Wilby A, Yarnell RW, Zamora V, Sutherland WJ (2021) Training future generations to deliver evidence‐based conservation and ecosystem management. Ecological Solutions and Evidence PDF DOI

Beyond species counts for assessing, valuing, and conserving biodiversity: response to Wallach et al. 2019

Authors: Ninon FV Meyer, Niko Balkenhol, Trishna Dutta, Maarten Hofman, Jean‐Yves Meyer, Euan G Ritchie, Charlotte Alley, Chad Beranek, Cassandra K Bugir, Alex Callen, Simon Clulow, Michael V Cove, Kaya Klop‐Toker, Omar R Lopez, Michael Mahony, Robert Scanlon, Sandeep Sharma, Elen Shute, Rose Upton, Emy Guilbault, Andrea S Griffin, Edwin Hernández Pérez, Lachlan G Howell, John‐Paul King, Dean Lenga, Patrick O Donoghue, and Matt W Hayward

Published in: Conservation Biology

Abstract

Combining native and non‐native species to evaluate biodiversity is overly simplistic and may undermine the conservation of ecosystems.

Meyer NFV, Balkenhol N, Dutta T, Hofman M, Meyer J, Ritchie EG, Alley C, Beranek C, Bugir CK, Callen A, Clulow S, Cove MV, Klop‐Toker K, Lopez OR, Mahony M, Scanlon R, Sharma S, Shute E, Upton R, Guilbault E, Griffin AS, Hernández Pérez E, Howell LG, King J, Lenga D, O Donoghue P, Hayward MW (2020) Beyond species counts for assessing, valuing, and conserving biodiversity: response to Wallach et al. 2019. Conservation Biology PDF DOI

Dietary variation of an endangered mycophagous mammal in novel and remnant habitats in a peri-urban landscape

Authors: Sarah J Maclagan, Terry Coates, Austin O’Malley, and Euan G Ritchie

Published in: Austral Ecology

Abstract

Understanding how fundamental aspects of species’ ecology, such as diet, are affected in human‐dominated landscapes is vital for informing management and conserving biodiversity – particularly where species influence important ecosystem functions. Digging, mycophagous (‘fungus‐eating’) mammals play various such roles, including the dispersal of hypogeal (‘truffle‐like’) fungi.

The endangered, mycophagous southern brown bandicoot (Isoodon obesulus obesulus: Peramelidae) persists in a peri‐urban landscape south‐east of Melbourne, Australia, where it occupies both ‘novel’ habitats (linear strips of vegetation along roadsides, drains and railway lines) and ‘remnant’ habitats (larger blocks of native vegetation) within dedicated conservation areas. It remains unknown how bandicoot diet, including the diversity of hypogeal fungi, varies between these habitat types, yet this could have important conservation implications.

Our study aimed to (i) compare the diet of I. o. obesulus at novel and remnant sites; and (ii) attain knowledge of hypogeal fungal diversity in these different contexts. We collected 133 bandicoot scats over 23 months and examined both broad diet composition and diversity of fungi consumed.

Bandicoot diet differed between site types; in particular, ants were more prominent in scats from remnant sites, while millipedes and seeds were more prominent in scats from novel sites. All scats contained fungal spores, with hypogeal taxa comprising at least 35 of the 78 ‘morphotypes’ found at novel sites and 28 of the 59 detected at remnant sites. Fewer samples were collected at remnant sites, but they appeared to contain a greater richness of hypogeal fungi per scat. We did not detect any differences in fungal composition between site types. However, our sampling effort was insufficient to estimate true morphotype richness at either site type.

Our study highlights the adaptable generalist diet of the southern brown bandicoot, as well as the likely under‐appreciated diversity of hypogeal fungi that can occur in highly modified, novel ecosystems.

Maclagan SJ, Coates T, O’Malley A, Ritchie EG (2020) Dietary variation of an endangered mycophagous mammal in novel and remnant habitats in a peri‐urban landscape. Austral Ecology PDF DOI

A guide to ecosystem models and their environmental applications

Authors: William L Geary, Michael Bode, Tim S Doherty, Elizabeth A Fulton, Dale G Nimmo, Ayesha I T Tulloch, Vivitskaia J D Tulloch, and Euan G Ritchie

Published in: Nature Ecology & Evolution

Abstract

Applied ecology has traditionally approached management problems through a simplified, single-species lens. Repeated failures of single-species management have led us to a new paradigm — managing at the ecosystem level. Ecosystem management involves a complex array of interacting organisms, processes and scientific disciplines. Accounting for interactions, feedback loops and dependencies between ecosystem components is therefore fundamental to understanding and managing ecosystems.

We provide an overview of the main types of ecosystem models and their uses, and discuss challenges related to modelling complex ecological systems. Existing modelling approaches typically attempt to do one or more of the following: describe and disentangle ecosystem components and interactions; make predictions about future ecosystem states; and inform decision making by comparing alternative strategies and identifying important uncertainties.

Modelling ecosystems is challenging, particularly when balancing the desire to represent many components of an ecosystem with the limitations of available data and the modelling objective. Explicitly considering different forms of uncertainty is therefore a primary concern.

We provide some recommended strategies (such as ensemble ecosystem models and multi-model approaches) to aid the explicit consideration of uncertainty while also meeting the challenges of modelling ecosystems.

Geary WL, Bode M, Doherty TS, Fulton EA, Nimmo DG, Tulloch AIT, Tulloch VJD, Ritchie EG (2020) A guide to ecosystem models and their environmental applications. Nature Ecology & Evolution PDF DOI

Consequences of information suppression in ecological and conservation sciences

Authors: Don A Driscoll, Georgia E Garrard, Alexander M Kusmanoff, Stephen Dovers, Martine Maron, Noel Preece, Robert L Pressey, and Euan G Ritchie

Published in: Conservation Letters

Abstract

Suppressing expert knowledge can hide environmentally damaging practices and policies from public scrutiny.

We surveyed ecologists and conservation scientists from universities, government, and industry across Australia to understand the prevalence and consequences of suppressing science communication.

Government (34%) and industry (30%) respondents reported higher rates of undue interference by employers than did university respondents (5%). Internal communications (29%) and media (28%) were curtailed most, followed by journal articles (11%), and presentations (12%). When university and industry researchers avoided public commentary, this was mainly for fear of media misrepresentation, while government employees were most often constrained by senior management and workplace policy. One third of respondents reported personal suffering related to suppression, including job losses and deteriorating mental health.

Substantial reforms are needed, including to codes of practice, and governance of environmental assessments and research, so that scientific advice can be reported openly, in a timely manner and free from interference.

Driscoll DA, Garrard GE, Kusmanoff AM, Dovers S, Maron M, Preece N, Pressey RL, Ritchie EG (2020) Consequences of information suppression in ecological and conservation sciences. Conservation Letters PDF DOI

Identifying and prioritizing human behaviors that benefit biodiversity

Authors: Matthew J Selinske, Georgia E Garrard, Emily A Gregg, Alexander M Kusmanoff, Lindall R Kidd, Meghan T Cullen, Michelle Cooper, William L Geary, Melissa A Hatty, Fern Hames, Sarah Kneebone, Emily M McLeod, Euan G Ritchie, Zoe E Squires, Janelle Thomas, Madelaine A W Willcock, Sera Blair, and Sarah A Bekessy

Published in: Conservation Science and Practice

Abstract

The conservation profession is increasingly seeking effective ways to reduce societal impact on biodiversity, including through targeted behavior change interventions. Multiple conservation behavior change programs exist, but there is also great uncertainty regarding which behaviors are most strategic to target.

Behavioral prioritization is a tool that has been used effectively to support behavior change decision‐making in other environmental disciplines and more recently for a small sub‐set of biodiversity behavior change challenges.

Here, we use behavioral prioritization to identify individual behaviors that could be modified to achieve biodiversity benefits in the state of Victoria, Australia. We use an adapted nominal group technique method to identify potential biodiversity behaviors and, for each behavior, estimate the corresponding plasticity (or capacity for change) and positive impact on biodiversity outcomes.

We elicited 27 behaviors that individuals could undertake to benefit or reduce their negative impact on biodiversity. This list was then used to prioritize 10 behaviors as determined by their likely effect(s) on biodiversity, plasticity, and current prevalence in Victoria. We take a first step in outlining a list of behaviors that can direct Victorian decision‐makers toward increasing positive and reducing negative impacts of society on biodiversity, guide motivated individuals to reduce their own biodiversity footprint, and more broadly, develop a behavior change research agenda for behaviors most likely to benefit biodiversity.

Selinske MJ, Garrard GE, Gregg EA, Kusmanoff AM, Kidd LR, Cullen MT, Cooper M, Geary WL, Hatty MA, Hames F, Kneebone S, McLeod EM, Ritchie EG, Squires ZE, Thomas J, Willcock MAW, Blair S, Bekessy SA (2020) Identifying and prioritizing human behaviors that benefit biodiversity. Conservation Science and Practice PDF DOI

Evaluation of camera placement for detection of free-ranging carnivores; implications for assessing population changes

Authors: Hayley M Geyle, Michael Stevens, Ryan Duffy, Leanne Greenwood, Dale G Nimmo, Derek Sandow, Ben Thomas, John White, and Euan G Ritchie

Published in: Ecological Solutions and Evidence

Abstract

Introduced carnivores are often cryptic, making it difficult to quantify their presence in ecosystems, and assess how this varies in relation to management interventions. Survey design should thus seek to improve detectability and maximize statistical power to ensure sound inference regarding carnivore population trends. Roads may facilitate carnivore movements, possibly leading to high detectability. Therefore, targeting roads may improve inferences about carnivore populations.

We assessed our ability to monitor feral cats Felis catus and red foxes Vulpes vulpes on‐ and off‐road, with explicit consideration of the location of monitoring sites on our ability to detect population changes. We also assessed whether there was evidence of spatial or temporal interaction between these species that might influence their road‐use.

Surveys were conducted in a conservation reserve in south‐eastern Australia between 2016 and 2018. At each of 30 sites, we deployed two motion‐sensor cameras, one on‐road, and the other off‐road. Using occupancy models, we estimated cat and fox occupancy and detectability, and conducted a power analysis to assess our ability to detect declines in occupancy under three monitoring regimes (efforts targeted equally on‐ and off‐road, efforts targeted entirely off‐road and efforts targeted entirely on‐road).

On average, on‐road detectability was seven times higher for cats and three times higher for foxes. Targeting survey effort on‐road yielded the greatest power for detecting declines in both species, but our ability to detect smaller declines decreased with decreasing initial occupancy probability. No level of decline was detectable for cats when survey efforts were targeted off‐road, while only large declines (>50%) were detectable for foxes (assuming high initial occupancy probabilities). We found little evidence of spatial or temporal segregation, suggesting limited avoidance or suppression between the two species within this landscape.

Our results suggest that targeting monitoring on roads may be an effective approach for detecting declines in introduced carnivore populations, particularly following management intervention (e.g. lethal control), and in the face of resource limitations. We provide a framework that can help assist land managers to make informed decisions, which balance monitoring efforts and resource constraints with sufficient statistical power to assess management objectives.

Geyle HM, Stevens M, Duffy R, Greenwood L, Nimmo DG, Sandow D, Thomas B, White J, Ritchie EG (2020) Evaluation of camera placement for detection of free‐ranging carnivores; implications for assessing population changes. Ecological Solutions and Evidence PDF DOI

Run rabbit run: spotted-tailed quoll diet reveals invasive prey is top of the menu

Authors: Grant D Linley, Annette Rypalski, Georgeanna Story, and Euan G Ritchie

Published in: Australian Mammalogy

Abstract

Information about the ecological functional roles of native predators may help inform the conservation of wildlife and pest management.

If predators show preferences for certain prey, such as invasive species, this could potentially be used as a conservation tool to help restore degraded (e.g. overgrazed) ecosystems via the reintroduction of native predators and suppression of exotic prey (e.g. introduced herbivores).

The diet of spotted-tailed quolls was studied in a fenced reserve in south-eastern Australia where native mammals have been reintroduced, foxes and cats removed, but invasive European rabbits still persist.

A total of 80 scats were collected over 12 months and analysis of macroscopic prey remains was conducted to determine diet.

Rabbits were by far the most commonly consumed prey species by volume (~76%) and frequency (~60%), followed by brushtail possums (~11% for both volume and frequency), and other small and medium-sized native mammals in much smaller amounts. Quoll scat analysis revealed 10 mammal species in total, eight of which were native. Bird, reptile and invertebrate remains were uncommon in quoll scats.

This suggests that spotted-tailed quolls may show a preference for preying on invasive European rabbits in certain contexts, and this could potentially be used as part of quoll reintroductions to aid rabbit population suppression and ecosystem restoration.

Linley GD, Rypalski A, Story G, Ritchie EG (2020) Run rabbit run: spotted-tailed quoll diet reveals invasive prey is top of the menu. Australian Mammalogy PDF DOI

Living with the enemy: a threatened prey species coexisting with feral cats on a fox-free island

Authors: Vivianna Miritis, Anthony R Rendall, Tim S Doherty, Amy L Coetsee, and Euan G Ritchie

Published in: Wildlife Research

Abstract

Context

Feral domestic cats (Felis catus) have contributed to substantial loss of Australian wildlife, particularly small- and medium-sized terrestrial mammals. However, mitigating cat impacts remains challenging.

Understanding the factors that facilitate coexistence between native prey and their alien predators could aid better pest management and conservation actions.

Aims

We estimated feral cat density, examined the impact of habitat cover on long-nosed potoroos (Potorous tridactylus tridactylus), and assessed the spatial and temporal interactions between cats and potoroos in the ‘Bluegums’ area of French Island, south-eastern Australia.

Materials and methods

We operated 31 camera stations across Bluegums for 99 consecutive nights in each of winter 2018 and summer 2018/19. We used a spatially explicit capture–recapture model to estimate cat density, and two-species single-season occupancy models to assess spatial co-occurrence of cats and potoroos.

We assessed the influence of vegetation cover and cat activity on potoroo activity by using a dynamic occupancy model. We also used image timestamps to describe and compare the temporal activities of the two species.

Key results

Bluegums had a density of 0.77 cats per km² across both seasons, although this is a conservative estimate because of the presence of unidentified cats.

Cats and long-nosed potoroos were detected at 94% and 77% of camera stations, respectively.

Long-nosed potoroo detectability was higher in denser vegetation and this pattern was stronger at sites with high cat activity.

Cats and potoroos overlapped in their temporal activity, but their peak activity times differed.

Conclusions

Feral cat density at Bluegums, French Island, is higher than has been reported for mainland Australian sites, but generally lower than in other islands.

Long-nosed potoroos were positively associated with cats, potentially indicating cats tracking potoroos as prey or other prey species that co-occur with potoroos.

Temporal activity of each species differed, and potoroos sought more complex habitat, highlighting possible mechanisms potoroos may use to reduce their predation risk when co-occurring with cats.

Implications

Our study highlighted how predator and prey spatial and temporal interactions, and habitat cover and complexity (ecological refuges), may influence the ability for native prey to coexist with invasive predators.

We encourage more consideration and investigation of these factors, with the aim of facilitating more native species to persist with invasive predators or be reintroduced outside of predator-free sanctuaries, exclosures and island safe havens.

Miritis V, Rendall AR, Doherty TS, Coetsee AL, Ritchie EG (2020) Living with the enemy: a threatened prey species coexisting with feral cats on a fox-free island. Wildlife Research PDF DOI

Moon phase and nocturnal activity of native Australian mammals

Authors: Grant D Linley, Yvette Pauligk, Courtney Marneweck, and Euan G Ritchie

Published in: Australian Mammology

Abstract

Moon phase and variation in ambient light conditions can influence predator and prey behaviour. Nocturnal predators locate prey visually, and prey may adjust their activity to minimise their predation risk. Understanding how native mammals in Australia respond to varying phases of the moon and cloud cover (light) enhances knowledge of factors affecting species’ survival and inference regarding ecological and population survey data.

Over a two-year period within a fenced conservation reserve, in south-eastern Australia, with reintroduced native marsupial predator and prey species (eastern barred bandicoot, southern brown bandicoot, long-nosed potoroo, rufous bettong, Tasmanian pademelon, brush-tailed rock-wallaby, red-necked wallaby, eastern quoll, spotted-tailed quoll, and naturally occurring swamp wallaby, common brushtail possum, common ringtail possum), we conducted monthly spotlight surveys during different moon phases (full, half and new moon).

We found an interaction between cloud cover and moon phase, and an interaction of the two depending on the mammal size and class. Increased activity of prey species corresponded with periods of increasing cloud cover. Predators and medium-sized herbivores were more active during times of low illumination.

Our findings suggest that moon phase affects the nocturnal activity of mammal species and that, for prey species, there might be trade-offs between predation risk and foraging. Our findings have implications for: ecological survey design and interpretation of results for mammal populations across moon phases, understanding predator and prey behaviour and interactions in natural and modified (artificial lighting) ecosystems, and potential nocturnal niche partitioning of species.

Linley GD, Pauligk Y, Marneweck C, Ritchie EG (2020) Moon phase and nocturnal activity of native Australian mammals. Australian Mammalogy PDF DOI

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

Authors: Michael L Wysong, Gwenllian D Iacona, Leonie E Valentine, Keith Morris, and Euan G Ritchie

Published in: Wildlife Research

Abstract

Context

To 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.

Aims

We 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.

Method

We deployed 80 remotely triggered camera traps over the 2,410-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 results

Cameras 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.

Conclusions

Camera 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.

Implications

Management 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).

Wysong ML, Iacona GD, Valentine LE, Morris K, Ritchie EG (2020) On the right track: placement of camera traps on roads improves detection of predators and shows non-target impacts of feral cat baiting. Wildlife Research PDF DOI

Space use and habitat selection of an invasive mesopredator and sympatric, native apex predator

Authors: Michael L Wysong, Bronwyn A Hradsky, Gwenllian D Iacona, Leonie E Valentine, Keith Morris, and Euan G Ritchie

Published in: Movement Ecology

Abstract

Background

Where mesopredators co-exist with dominant apex predators, an understanding of the factors that influence their habitat and space use can provide insights that help guide wildlife conservation and pest management actions.

A predator’s habitat use is defined by its home range, which is influenced by its selection or avoidance of habitat features and intra- and inter-specific interactions within the landscape. These are driven by both innate and learned behaviour, operating at different spatial scales.

We examined the seasonal home ranges and habitat selection of actively-managed populations of a native apex predator (dingo Canis dingo) and invasive mesopredator (feral cat Felis catus) in semi-arid Western Australia to better understanding their sympatric landscape use, potential interactions, and to help guide their management.

Methods

We used kernel density estimates to characterise the seasonal space use of dingoes and feral cats, investigate inter- and intra-species variation in their home range extent and composition, and examine second-order habitat selection for each predator. Further, we used discrete choice modelling and step selection functions to examine the difference in third-order habitat selection across several habitat features.

Results

The seasonal home ranges of dingoes were on average 19.5 times larger than feral cats. Feral cat seasonal home ranges typically included a larger proportion of grasslands than expected relative to availability in the study site, indicating second-order habitat selection for grasslands.

In their fine-scale movements (third-order habitat selection), both predators selected for roads, hydrological features (seasonal intermittent streams, seasonal lakes and wetlands), and high vegetation cover. Dingoes also selected strongly for open woodlands, whereas feral cats used open woodlands and grasslands in proportion to availability.

Management recommendations

Based on these results, and in order to avoid unintended negative ecological consequences (e.g. mesopredator release) that may stem from non-selective predator management, we recommend that feral cat control focuses on techniques such as trapping and shooting that are specific to feral cats in areas where they overlap with apex predators (dingoes), and more general techniques such as poison baiting where they are segregated.

Wysong ML, Hradsky BA, Iacona GD, Valentine LE, Morris K, Ritchie EG (2020) Space use and habitat selection of an invasive mesopredator and sympatric, native apex predator. Movement Ecology PDF DOI