Category Archives: Publications

Diversity in Australia’s tropical savannas: An integrative taxonomic revision of agamid lizards from the genera Amphibolurus and Lophognathus (Lacertilia: Agamidae)

Authors: Jane Melville, Euan G Ritchie, Stephanie N J Chapple, Richard E Glor And James A Schulte II

Published in: Memoirs of Museum Victoria, volume 77

Abstract

The taxonomy of many of Australia’s agamid lizard genera remains unresolved because morphological characters have proved to be unreliable across numerous lineages. We undertook a morphological study and integrated this with a recent genetic study to resolve long-standing taxonomic problems in three genera of large-bodied Australian agamid lizards: Amphibolurus, Gowidon and Lophognathus. We had broad geographic sampling across genera, including all currently recognised species and subspecies.

Using an integrative taxonomic approach, incorporating mitochondrial (ND2) and nuclear (RAG1) genetic data, and our morphological review, we found that both generic and species-level taxonomic revisions were required. We revise generic designations, creating one new genus (Tropicagama gen. nov.) and confirming the validity of Gowidon, giving a total of four genera. In addition, we describe a new species (Lophognathus horneri sp. nov.) and reclassify two other species.

Our results provide a significant step forward in the taxonomy of some of Australia’s most iconic and well-known lizards and provide a clearer understanding of biogeographic patterns across Australia’s monsoonal and arid landscapes.

Melville J, Ritchie EG, Chapple SNJ, Glor RE Schulte II JA (2018) Diversity in Australia’s tropical savannas: An integrative taxonomic revision of agamid lizards from the genera Amphibolurus and Lophognathus (Lacertilia: Agamidae). Memoirs of Museum Victoria PDF DOI

Towards meaningful monitoring: A case study of a threatened rodent

Authors: Hayley M Geyle, Gurutzeta Guillera‐Arroita, Hugh F Davies, Ronald S C Firth, Brett P Murphy, Dale G Nimmo, Euan G Ritchie, John C Z Woinarski, and Emily Nicholson

Published in: Austral Ecology

Abstract

Detecting trends in species’ distribution and abundance are essential for conserving threatened species, and depend upon effective monitoring programmes. Despite this, monitoring programmes are often designed without explicit consideration of their ability to deliver the information required by managers, such as their power to detect population changes.

Here, we demonstrate the use of existing data to support the design of monitoring programmes aimed at detecting declines in species occupancy. We used single‐season occupancy models and baseline data to gain information on variables affecting the occupancy and detectability of the threatened brush‐tailed rabbit‐rat Conilurus penicillatus (Gould 1842) on the Tiwi Islands, Australia. This information was then used to estimate the survey effort required to achieve sufficient power to detect changes in occupancy of different magnitudes.

We found that occupancy varied spatially, driven primarily by habitat (canopy height and cover, distance to water) and fire history across the landscape. Detectability varied strongly among seasons, and was three times higher in the late dry season (July–September), compared to the early dry season (April–June). Evaluation of three monitoring scenarios showed that conducting surveys at times when detectability is highest can lead to a substantial improvement in our ability to detect declines, thus reducing the survey effort and costs.

Our study highlights the need for careful consideration of survey design related to the ecology of a species, as it can lead to substantial cost savings and improved insight into species population change via monitoring.

Geyle HM, Guillera-Arroita G, Davies HF, Firth RSC, Murphy BP, Nimmo DG, Ritchie EG, Woinarski JCZ, Nicholson E (2018) Towards meaningful monitoring: A case study of a threatened rodent. Austral Ecology, PDF DOI

Continental patterns in the diet of a top predator: Australia’s dingo

Authors: Tim S Doherty, Naomi E Davis, Chris R Dickman, David M Forsyth, Mike Letnic, Dale G Nimmo, Russell Palmer, Euan G Ritchie, Joe Benshemesh, Glenn Edwards, Jenny Lawrence, Lindy Lumsden, Charlie Pascoe, Andy Sharp, Danielle Stokeld, Cecilia Myers, Georgeanna Story, Paul Story, Barbara Triggs, Mark Venosta, Mike Wysong, and Thomas M Newsome

Published in: Mammal Review

Abstract

Conserving large carnivores is controversial because they can threaten wildlife, human safety, and livestock production. Since large carnivores often have large ranges, effective management requires knowledge of how their ecology and functional roles vary biogeographically.

We examine continental‐scale patterns in the diet of the dingo – Australia’s largest terrestrial mammalian predator. We describe and quantify how dingo dietary composition and diversity vary with environmental productivity and across five bioclimatic zones: arid, semi‐arid, tropical, sub‐tropical, and temperate.

Based on 73 published and unpublished data sets from throughout the continent, we used multivariate linear modelling to assess regional trends in the occurrence of nine food groups (arthropods, birds, reptiles, European rabbits Oryctolagus cuniculus, medium‐sized (25–125 kg) and large (169–825 kg) exotic ungulates (including livestock), and other small (<0.5 kg) medium‐sized (0.5–6.9 kg) and large (≥7 kg) mammals) in dingo diets. We also assessed regional patterns in the dietary occurrence of livestock and the relationship between dietary occurrence of rabbits and small, medium‐sized and large mammals.

Dingoes eat at least 229 vertebrate species (66% mammals, 22% birds, 11% reptiles, and 1% other taxa). Dietary composition varied across bioclimatic zones, with dingo diets in the arid and semi‐arid zones (low‐productivity sites) having the highest occurrence of arthropods, reptiles, birds, and rabbits. Medium‐sized mammals occurred most frequently in temperate and sub‐tropical zone diets (high‐productivity sites), large mammals least in the arid and sub‐tropical zones, and livestock most in the arid and tropical zones. The frequency of rabbits in diets was negatively correlated with that of medium‐sized, but not small or large mammals.

Dingoes have a flexible and generalist diet that differs among bioclimatic zones and with environmental productivity in Australia. Future research should focus on examining how dingo diets are affected by local prey availability and human‐induced changes to prey communities.

Doherty TS, Davis NE, Dickman CR, Forsyth DM, Letnic M, Nimmo DG, Palmer R, Ritchie EG, Benshemesh J, Edwards G, Lawrence J, Lumsden L, Pascoe C, Sharp A, Stokeld D, Myers C, Story G, Story P, Triggs B, et al. (2018) Continental patterns in the diet of a top predator: Australia’s dingo, Mammal Review, PDF DOI

Species definitions shape policy

Authors: Euan G Ritchie, Bradley P Smith, Lily M van Eeden, and Dale G Nimmo

Published in: Science, volume 361, issue 6,409 (September 2018)

The names we assign to organisms, and why, have important ramifications for our understanding of Earth’s diversity and, more practically, how it is managed. For example, wolves, coyotes, domestic dogs, and other canids are often considered distinct (1), but their members can, and frequently do, interbreed (2). Differing concepts of species—which might take into account morphology, ecology, behaviour, genetics, or evolutionary history (3) —could describe canids as very few or many species, depending on which concepts are used and how strictly they are applied. Which definition scientists adopt can have political and ecological consequences.

The dingo (Canis dingo) has traditionally been considered native in Australia, given evidence of its presence before the year 1400 (4) and indications that it has lived in Australia for at least 5,000 years (5). This designation meant that Western Australia had to have a management strategy in place for the dingo, along with other native fauna. However, a recent paper (6) argues that dingoes are in fact C. familiaris because they don’t satisfy zoological nomenclature protocols nor sufficiently differ genetically or morphologically from other canids, including domestic dogs.

The Western Australian government cited this work in justifying its recent decision to declare the dingo a non-native species under the state’s Biodiversity Conservation Act (BCA) (7). The new order removesthe government requirement to manage the species. As a result, dingoes can now be killed anywhere in the state without a BCA license. A potential increase in lethal control of dingoes could have dire consequences for Australia’s ecosystems. The dingo is Australia’s largest terrestrial top predator (adults typically weigh 15 to 20 kg (8)), it fulfils a crucial ecological role, and it has strong cultural significance for Australia’s Indigenous people (8).

Taxonomy serves a critical purpose for cataloguing and conserving biodiversity, but different interpretations and applications of species concepts can affect management decisions. Policy-makers may use the interpretations that justify their preferred values, such as prioritizing livestock more than biodiversity protection. It is therefore imperative that scientists carefully engage in the policy decision-making process. Scientists must work with policy-makers to convey the multiple dimensions and values that can affect species delineation and make clear the potential consequences of applying such classifications.

  1.  J.Clutton-Brocketal.,Bull.Br.Mus.Nat.Hist.Zool. 29,117 (1976).
  2. Z.Fanetal.,Gen.Res.26,163(2016).
  3. F.E.Zachos, Mammal Rev.10.1111/mam.12121(2018).
  4. Department of the Environment and Energy, Australian Government, “Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)” (1999); http://www.environment.gov.au/epbc
  5. K.M.Cairns, A.N.Wilton, Genetica 144,553(2016).
  6. S.M.Jackson et al., Zootaxa 4317,201(2017).
  7. M.Bamford, “Dingoes to remain classified as non-native wild dogs under reform to Western Australian law,” ABC News (2018); http://www.abc.net.au/news/2018-08-28/dingoes-will-no-longer-be-native-animals-in-western-australia/10172448
  8. M.Letnic et al., Biol.Rev. 87,390(2012).

Ritchie EG, Smith BP, van Eeden LM, Nimmo DG (2018) Species definitions shape policy, Science PDF DOI

Expanding the role of targets in conservation policy

Authors: Tim S Doherty, Lucie M Bland Brett A Bryan, Timothy Neale, Emily Nicholson, Euan G Ritchie, and Don A Driscoll

Published in: Trends in Ecology & Evolution

Conservation targets perform beneficial auxiliary functions that are rarely acknowledged, including raising awareness, building partnerships, promoting investment, and developing new knowledge. Building on these auxiliary functions could enable more rapid progress towards current targets and inform the design of future targets.

Doherty TS, Bland LM, Bryan BA, Neale T, Nicholson E, Ritchie EG, Driscoll DA (2018) Expanding the Role of Targets in Conservation Policy, Trends in Ecology & Evolution, PDF DOI 

Carnivore conservation needs evidence-based livestock protection

Authors: Lily M van Eeden, Ann Eklund, Jennifer R B Miller, José Vicente López-Bao, Guillaume Chapron, Mikael R Cejtin, Mathew S Crowther, Christopher R Dickman, Jens Frank, Miha Krofel, David W Macdonald, Jeannine McManus, Tara K Meyer, Arthur D Middleton, Thomas M Newsome, William J Ripple, Euan G Ritchie, Oswald J Schmitz, Kelly J Stoner, Mahdieh Tourani, Adrian Treves

Published in: PloS Biology

Abstract

Carnivore predation on livestock often leads people to retaliate. Persecution by humans has contributed strongly to global endangerment of carnivores. Preventing livestock losses would help to achieve three goals common to many human societies: preserve nature, protect animal welfare, and safeguard human livelihoods.

Between 2016 and 2018, four independent reviews evaluated >40 years of research on lethal and nonlethal interventions for reducing predation on livestock. From 114 studies, we find a striking conclusion: scarce quantitative comparisons of interventions and scarce comparisons against experimental controls preclude strong inference about the effectiveness of methods.

For wise investment of public resources in protecting livestock and carnivores, evidence of effectiveness should be a prerequisite to policy making or large-scale funding of any method or, at a minimum, should be measured during implementation.

An appropriate evidence base is needed, and we recommend a coalition of scientists and managers be formed to establish and encourage use of consistent standards in future experimental evaluations.

van Eeden LM, Eklund A, Miller JRB, López-Bao JV, Chapron G, Cejtin MR, Crowther MS, Dickman CR, Frank J, Krofel M, Macdonald DW, McManus J, Meyer TK, Middleton AD, Newsome TM, Ripple WJ, Ritchie EG, Schmitz OJ, Stoner KJ, Tourani M, Treveset A (2018) Carnivore conservation needs evidence-based livestock protection, PLOS Biology PDF DOI 

The Conversation: A numbers game: killing rabbits to conserve native mammals

Controlling rabbit populations has a key role in conserving Australia’s native plants and animals

By Euan Ritchie (Deakin University), Damien Fordham (University of Adelaide), and Miguel Lurgi, (Centre national de la recherche scientifique)

This article was originally published on The Conversation. Read the original article.

Invasive species have a devastating effect on biodiversity. In Australia, introduced red foxes and feral cats have been implicated in the majority of the extinctions of the native mammal fauna, which has been decimated since European arrival.

But there’s a herbivore that also causes eco-catastrophe. Rabbits both compete with native animals for food and shelter and act as easy prey for abundant populations of cats and foxes. By over-grazing vegetation and reducing habitat complexity, they make hunting easier for introduced predators.

Food webs are complex. Because of this, once an invasive species is embedded in a food web, simply eradicating them without considering the potential knock-on effects to other species they interact with, could cause unintended and undesirable consequences. We modelled different rates of rabbit population reduction to assess what level of control might be best for aiding the conservation of native mammals and not causing negative outcomes.

Rabbit numbers boom and crash

Rabbits, famously, reproduce rapidly and can cope with a relatively high predation rate. This can cause “hyper-predation”, where rabbit-inflated cat and fox populations indirectly increase the predation pressure on native mammals. This is especially so when rabbit populations intermittently crash due to, for example, extreme environmental events (like severe and prolonged droughts) or disease. This causes predators to switch their diet and eat more native mammals.

This logically suggests that reducing rabbit numbers might thus help reduce cat and fox populations, by removing their abundant prey. Collectively this should benefit native plants and animals, including many threatened mammal species. However, ecosystem and pest management is a complex game.

When controlling rabbits we need to look beyond one or two species. We should consider the potential consequences for the entire ecological community, which ultimately depend on how changes in one species percolate through the network of ecological interactions between them.

Our new research, recently published in the Journal of Applied Ecology, set out to examine these questions in more detail. We consider other key players in Australia’s arid regions, such as kangaroos and dingoes, when looking at the effects of rabbit control on small native mammals. Our aim was to provide a better understanding of how changes in rabbit populations might affect other species via the food web.

We developed a multi-species ecological network model to describe and quantify how changing rabbit abundance can affect species on different feeding levels. In addition to rabbits, small native mammals, and mesopredators (cats and foxes), our model also considers apex predators (dingo) and large herbivores (kangaroo) as part of the Australian arid food web. This model allowed us to examine changes in predator-prey interactions (including potential prey switching and hyper-predation) and how these could affect the survival of native prey through time.

We found that removing rabbits at rates between 30-40% appeared to benefit small mammals. This is approximately the rate at which rabbits are currently managed in Australia using biocontrol agents (introduced diseases).

Rabbit control in Australia typically involves a “press and pulse” approach. Rabbit populations are suppressed via biocontrol (press) and periods of warren destruction and poisoning (pulse). Finding that reducing rabbit populations by around 40% seems most beneficial to small mammals is important, as it informs how and when we combine these strategies.

The 40% rate corresponds well with the disease-induced (press) mortality rate in rabbit populations due to rabbit haemorrhagic disease and myxomatosis. These are the primary biocontrol agents used in arid Australia to control rabbit populations.

Our study supports rabbit-reduction strategies that involve sustained “press” control, that kill a moderate portion of a rabbit population, with less frequent removal at higher proportions of the population.

To effectively manage invasive species, it’s important to focus on entire communities. Targeting single species might not be enough – every animal exists within a complex web of interactions.

There has been much focus by the current government on controlling feral cats, as a way to conserve many of Australia’s unique and threatened mammal species.

However, more focus could be devoted to protecting habitat cover and complexity, by reducing the land clearing and over-grazing that makes hunting easier. We can also manage rabbits sensibly to reduce competition for resources, and indirectly control cats and foxes.
The Conversation

Eradicating abundant invasive prey could cause unexpected and varied biodiversity outcomes: The importance of multispecies interactions

Authors: Miguel Lurgi, Euan G Ritchie, and Damien A Fordham

Published in: Journal of Applied Ecology

Abstract

Abundant and widely distributed invasive prey can negatively affect co‐occurring native species by competing for food and/or shelter, removing vegetation cover and reducing habitat complexity (changing predation risk), and by sustaining elevated abundances of invasive mesopredators. However, information regarding the community and trophic consequences of controlling invasive prey and their temporal dynamics remain poorly understood.

We used multispecies ecological network models to simulate the consequences of changing European rabbit Oryctolagus cuniculus abundance in an arid mammalian community. We quantified how changes in the dominant prey (rabbits) affected multiple trophic levels, examining changes in predator–prey interactions through time and how they affected native prey persistence.

Our results suggest that removal of rabbits can benefit native biodiversity immediately at removal rates between 30% and 40%. However, beyond these levels, densities of small native mammals will decline in the short term. The processes underpinning these declines are: (a) increased competition for resources (vegetation) with kangaroos Macropus spp., whose numbers increase due to their release from competition with rabbits and (b) increased predation (prey switching) by feral cats Felis catus. Both effects are mediated by dingoes Canis dingo, a native apex predator.

Importantly, native mammal abundance recovers after a time delay, which is prolonged when high rates of rabbit control are applied. This is likely due to a reduction in hyperpredation by invasive feral cats and red foxes Vulpes vulpes following rabbit removal.

Continued eradication of rabbits in arid Australia will benefit native species due to a decrease in apparent competition for resources and by alleviating hyperpredation from invasive mesopredators. Furthermore, ecosystem‐level conservation benefits of reducing invasive prey abundance are as important as direct control of invasive mesopredators.

Synthesis and applications: Multispecies ecological network models provide wildlife managers with tools to better understand and predict the complex effects of species removal and control on both intact and modified ecosystems. Our results show that management of the Australian arid zone can benefit from controlling invasive prey as well as invasive predators. However, invasive species control can cause unexpected outcomes on native biodiversity. This extends to other systems where dominant prey may play fundamental roles in ecosystem structure and function.

Lurgi M, Ritchie EG, Fordham DA (2018) Eradicating abundant invasive prey could cause unexpected and varied biodiversity outcomes: The importance of multispecies interactions, Journal of Applied Ecology, PDF DOI 

Evaluating the efficacy of predator removal in a conflict-prone world

Authors: Robert J Lennox, Austin J Gallagher, Euan G Ritchie, and Steven J Cooke

Published in: Biological Conservation, volume 224 (August 2018)

Abstract

Predators shape ecosystem structure and function through their direct and indirect effects on prey, which permeate through ecological communities. Predators are often perceived as competitors or threats to human values or well-being. This conflict has persisted for centuries, often resulting in predator removal (i.e. killing) via targeted culling, trapping, poisoning, and/or public hunts. Predator removal persists as a management strategy but requires scientific evaluation to assess the impacts of these actions, and to develop a way forward in a world where human-predator conflict may intensify due to predator reintroduction and rewilding, alongside an expanding human population.

We reviewed literature investigating predator removal and focused on identifying instances of successes and failures. We found that predator removal was generally intended to protect domestic animals from depredation, to preserve prey species, or to mitigate risks of direct human conflict, corresponding to being conducted in farmland, wild land, or urban areas. Because of the different motivations for predator removal, there was no consistent definition of what success entailed so we developed one with which to assess studies we reviewed. Research tended to be retrospective and correlative and there were few controlled experimental approaches that evaluated whether predator removal met our definition of success, making formal meta-analysis impossible. Predator removal appeared to only be effective for the short-term, failing in the absence of sustained predator suppression. This means predator removal was typically an ineffective and costly approach to conflicts between humans and predators.

Management must consider the role of the predator within the ecosystem and the potential consequences of removal on competitors and prey. Simulations or models can be generated to predict responses prior to removing predators. We also suggest that alternatives to predator removal be further developed and researched.

Ultimately, humans must coexist with predators and learning how best to do so may resolve many conflicts.

Lennox RJ, Gallagher AJ, Ritchie EG, Cooke SJ (2018) Evaluating the efficacy of predator removal in a conflict-prone world, Biological Conservation, PDF DOI

Crowdfunded campaigns are conserving the Earth’s environment

Crowdfunded campaigns to save the orange-bellied parrot are a rare ray of hope. Image credit: Fatih Sam

By Eduardo Gallo-Cajiao (University of Queensland), Carla Archibald (University of Queensland), Euan Ritchie (Deakin University), Rachel Friedman (University of Queensland), Richard Fuller (The University of Queensland), Rochelle Steven (University of Queensland), and Tiffany Morrison (James Cook University)

This article was originally published on The Conversation. Read the original article, including reader comments.

If not for the public’s generosity, the iconic Statue of Liberty might not have the solid and impressive footing she does today. In the late 1800s, government funds for the monument were exhausted. Yet through a fundraising campaign, the New York World newspaper garnered support from over 160,000 residents to cover the pedestal costs.

Just as large monuments need solid bases to ensure their long-term existence, so too does the environment. In the case of nature conservation, it requires money to support diverse research projects, on-ground activities, and outreach aimed at protecting and managing species and habitats.

While the health of the environment continues to decline globally, in most regions government funding falls short of what is required to stem the losses. Crowdfunding plays an important and under-appreciated role for biodiversity conservation.

Our new research presents a global analysis of how crowdfunding, still a relatively novel and minor financial mechanism in the conservation community, is contributing to conservation around the world.

Show me the money. What’s being funded and why?

Crowdfunding offers a powerful mechanism for mobilising resources for conservation across borders. We recorded 577 conservation-oriented projects (from 72 crowdfunding platforms), which have raised around US$4.8 million since 2009. The people leading these projects were based in 38 countries, but projects took place across 80 countries.

This pattern has important implications for conservation, because there is often a mismatch between high-priority areas for global conservation and countries with the greatest financial and technical capacity. For instance, we discovered that a third of the projects were delivered in different countries to where their proponents were based. The USA, UK and Australia were the countries with the highest outflow of projects (“project exporters”). Indonesia, South Africa, Costa Rica and Mexico had the highest inflow (“project importers”).

Crowdfunding could be supporting conservation work of actors that do not have as much capacity for raising funds.

The people leading projects were primarily from non-governmental organisations (35%) or universities (30%), or were freelancers (26%). Importantly, among non-governmental organisations, we discovered organisations operating at sub-national levels proposed a majority of projects.

Additionally, crowdfunding for conservation is not all about research. While most of the projects we reviewed focused on research (40%), many tackled raising awareness of conservation-related issues (31%) or boots-on-the-ground activities (21%). This expands the sphere of anecdotal evidence and commentary about crowdfunding related to conservation, which has so far revolved around research. For the first time, we’ve systematically unpacked how these funds are being used for additional activities to support conservation.

Crowdfunding can also support innovative projects that traditional funding agencies deem too risky or unconventional. For example, one project supported buying and training two Maremma sheepdogs to protect penguins against predatory foxes in southeastern Australia. (That might sound familiar to those who’ve seen the movie Oddball.)

Such opportunities for innovation can have important consequences for conservation worldwide; crowdfunding could be considered an incubator for novel ideas before widespread dissemination.

More than half of the projects we recorded (around 58%) largely focused on species. These included a disproportionate number of threatened bird and mammal species.

Prominent projects to save orange-bellied parrots or Papua New Guinea’s endangered tree kangaroos are important success stories.

This is not to underplay crowdfunding’s importance for ecosystems – whether land-based (20%), marine (9%) or freshwater (4%). Crowfunding is supporting projects ranging from protection of wilderness areas in remote Tasmania to research informing the conservation of the Californian coast.

Crowdfunding benefits extend beyond dollars and cents

The amount of money for conservation via crowdfunding has so far been relatively modest compared to more traditional conservation finance mechanisms. However, the benefits of crowdfunding extend well beyond dollars and cents. Crowdfunding helps communicate environmental issues and empower researchers and communities.

The figure below shows the reach of a single tweet during the Big Roo Count campaign. It shows how conservation-related messages can spread widely and engage communities via social media.

Crowdfunding is an exciting new tool in the conservation toolbox. But, ultimately, traditional funding sources, like government agencies, still have a major role and duty to invest adequately in environmental protection and nature conservation. Considering the current extinction crisis, governments must avoid further outsourcing of such responsibilities.

The discussion over novel sources and recipients of conservation funding continues. At the same time, transparency and oversight remain critical for managing expectations and overall effectiveness of funding. Crowdfunding contributes one more building block to democratising conservation funding and increasing transparency.

The authors would like to acknowledge the contribution of Edward Game.
The Conversation

Animal recognition and identification with deep convolutional neural networks for automated wildlife monitoring

Authors: Hung Nguyen, Sarah J Maclagan, Tu Dinh Nguyen, Thin Nguyen, Paul Flemons, Kylie Andrews, Euan G Ritchie, and Dinh Phung

Published in: 2017 IEEE International Conference on Data Science and Advanced Analytics

Abstract

Efficient and reliable monitoring of wild animals in their natural habitats is essential to inform conservation and management decisions. Automatic covert cameras or “camera traps” are being an increasingly popular tool for wildlife monitoring due to their effectiveness and reliability in collecting data of wildlife unobtrusively, continuously and in large volume. However, processing such a large volume of images and videos captured from camera traps manually is extremely expensive, time-consuming and also monotonous. This presents a major obstacle to scientists and ecologists to monitor wildlife in an open environment.

Leveraging on recent advances in deep learning techniques in computer vision, we propose in this paper a framework to build automated animal recognition in the wild, aiming at an automated wildlife monitoring system. In particular, we use a single-labeled dataset from Wildlife Spotter project, done by citizen scientists, and the state-of-the-art deep convo- lutional neural network architectures, to train a computational system capable of filtering animal images and identifying species automatically.

Our experimental results achieved an accuracy at 96.6% for the task of detecting images containing animal, and 90.4% for identifying the three most common species among the set of images of wild animals taken in South-central Victoria, Australia, demonstrating the feasibility of building fully automated wildlife observation. This, in turn, can therefore speed up research findings, construct more efficient citizen science- based monitoring systems and subsequent management decisions, having the potential to make significant impacts to the world of ecology and trap camera images analysis.

Nguyen H, Maclagan SJ, Nguyen TD, Nguyen T, Flemons P, Andrews K, Ritchie EG, Phung D (2017) Animal recognition and identification with deep convolutional neural networks for automated wildlife monitoring, 2017 IEEE International Conference on Data Science and Advanced Analytics PDF DOI 

Futurecasting ecological research: the rise of technoecology

Authors: Blake M Allan, Dale G Nimmo, Daniel Ierodiaconou, Jeremy VanDerWal, Lian Pin Koh, and Euan G Ritchie

Published in: Ecosphere, volume 9, issue 5 (May 2018)

Abstract

Increasingly complex research questions and global challenges (e.g., climate change and biodiversity loss) are driving rapid development, refinement, and uses of technology in ecology. This trend is spawning a distinct sub‐discipline, here termed “technoecology.”

We highlight recent ground‐breaking and transformative technological advances for studying species and environments: bio‐batteries, low‐power and long‐range telemetry, the Internet of things, swarm theory, 3D printing, mapping molecular movement, and low‐power computers. These technologies have the potential to revolutionize ecology by providing “next‐generation” ecological data, particularly when integrated with each other, and in doing so could be applied to address a diverse range of requirements (e.g., pest and wildlife management, informing environmental policy and decision making).

Critical to technoecology’s rate of advancement and uptake by ecologists and environmental managers will be fostering increased interdisciplinary collaboration. Ideally, such partnerships will span the conception, implementation, and enhancement phases of ideas, bridging the university, public, and private sectors.

Allan BM, Nimmo DG, Ierodiaconou D, VanDerWal J, Koh LP, Ritchie EG (2018) Futurecasting ecological research: the rise of technoecology, Ecosphere PDF DOI

Don’t judge habitat on its novelty: Assessing the value of novel habitats for an endangered mammal in a peri-urban landscape

Authors: Sarah J Maclagan, Terry Coates, and Euan G Ritchie

Published in: Biological Conservation, volume 223 (July 2018)

Abstract

Novel ecosystems are increasingly common worldwide, particularly in areas heavily impacted by humans such as urban and peri-urban landscapes. Consequently, interest in their potential contribution to biodiversity conservation is growing, including their ability to sustain populations of threatened species. However, few studies have explored whether novel habitats can support viable populations over time and how they compare to less modified, remnant habitats.

We investigated the capacity for novel habitats to support an endangered mammal, the southern brown bandicoot (Isoodon obesulus obesulus: Peramelidae), in a highly-modified landscape near Australia’s second largest city, Melbourne. We compared bandicoot abundance and body condition between five novel and two remnant sites, and examined whether novel sites support residency and key demographic processes necessary for bandicoot population persistence. We found that bandicoot abundance was higher at novel than remnant sites, with the highest abundance at the novel site with the most urbanised surroundings. Female body condition was similar between novel and remnant sites. The majority of bandicoots at novel sites were resident, and breeding activity, recruitment of first-year adults, and survival of mature adults were observed at all novel sites.

Our results demonstrate the potential significance of novel habitats for conserving threatened species within heavily-modified landscapes, and encourage us not to judge the quality of habitats on their novelty alone. Broadening our appreciation of the potential value of novel ecosystems could increase off-reserve species conservation opportunities, a key priority within the context of the Anthropocene and unprecedented global change and biodiversity loss.

Maclagan SJ, Coates T, Ritchie EG (2018) Don’t judge habitat on its novelty: Assessing the value of novel habitats for an endangered mammal in a peri-urban landscape, Biological Conservation PDF DOI 

Testing the assumptions of the pyrodiversity begets biodiversity hypothesis for termites in semi-arid Australia

Authors: Hayley Davis, Euan G Ritchie, Sarah Avitabile, Tim Doherty, and Dale G Nimmo

Published in: The Royal Society Open Science (April 2018)

Abstract

Fire shapes the composition and functioning of ecosystems globally. In many regions, fire is actively managed to create diverse patch mosaics of fire-ages under the assumption that a diversity of post-fire-age classes will provide a greater variety of habitats, thereby enabling species with differing habitat requirements to coexist, and enhancing species diversity (the pyrodiversity begets biodiversity hypothesis). However, studies provide mixed support for this hypothesis.

Here, using termite communities in a semi-arid region of southeast Australia, we test four key assumptions of the pyrodiversity begets biodiversity hypothesis:

  1. that fire shapes vegetation structure over sufficient time frames to influence species’ occurrence,
  2. that animal species are linked to resources that are themselves shaped by fire and that peak at different times since fire,
  3. that species’ probability of occurrence or abundance peaks at varying times since fire, and
  4. that providing a diversity of fire-ages increases species diversity at the landscape scale.

Termite species and habitat elements were sampled in 100 sites across a range of fire-ages, nested within 20 landscapes chosen to represent a gradient of low to high pyrodiversity. We used regression modelling to explore relationships between termites, habitat and fire.

Fire affected two habitat elements (coarse woody debris and the cover of woody vegetation) that were associated with the probability of occurrence of three termite species and overall species richness, thus supporting the first two assumptions of the pyrodiversity hypothesis. However, this did not result in those species or species richness being affected by fire history per se. Consequently, landscapes with a low diversity of fire histories had similar numbers of termite species as landscapes with high pyrodiversity.

Our work suggests that encouraging a diversity of fire-ages for enhancing termite species richness in this study region is not necessary.

Davis H, Ritchie EG, Avitabile S, Doherty T, Nimmo DG (2018) Testing the assumptions of the pyrodiversity begets biodiversity hypothesis for termites in semi-arid Australia, Royal Society Open Science PDF DOI 

Quantifying extinction risk and forecasting the number of impending Australian bird and mammal extinctions

Authors: Hayley M Geyle, John CZ Woinarski, G Barry Baker, Chris R Dickman, Guy Dutson, Diana O Fisher, Hugh Ford, Mark Holdsworth, Menna E Jones, Alex Kutt, Sarah Legge, Ian Leiper, Richard Loyn, Brett P Murphy, Peter Menkhorst, April E Reside, Euan G Ritchie, Finley E Roberts, Reid Tingley and Stephen T Garnett

Published in: Pacific Conservation Biology

Abstract

A critical step towards reducing the incidence of extinction is to identify and rank the species at highest risk, while implementing protective measures to reduce the risk of extinction to such species. Existing global processes provide a graded categorisation of extinction risk.

Here we seek to extend and complement those processes to focus more narrowly on the likelihood of extinction of the most imperilled Australian birds and mammals. We considered an extension of existing IUCN and NatureServe criteria, and used expert elicitation to rank the extinction risk to the most imperilled species, assuming current management.

On the basis of these assessments, and using two additional approaches, we estimated the number of extinctions likely to occur in the next 20 years. The estimates of extinction risk derived from our tighter IUCN categorisations, NatureServe assessments and expert elicitation were poorly correlated, with little agreement among methods for which species were most in danger – highlighting the importance of integrating multiple approaches when considering extinction risk.

Mapped distributions of the 20 most imperilled birds reveal that most are endemic to islands or occur in southern Australia. The 20 most imperilled mammals occur mostly in northern and central Australia.

While there were some differences in the forecasted number of extinctions in the next 20 years among methods, all three approaches predict further species loss.

Overall, we estimate that another seven Australian mammals and 10 Australian birds will be extinct by 2038 unless management improves.

Geyle HM, Woinarski JCZ, Baker GB, Dickman CR, Dutson G, Fisher DO, Ford H, Holdsworth M, Jones ME, Kutt A, Legge S, Leiper I, Loyn R, Murphy BP, Menkhorst P, Reside AE, Ritchie EG, Roberts FE, Tingley R, Garrett ST (2018) Quantifying extinction risk and forecasting the number of impending Australian bird and mammal extinctions, Pacific Conservation Biology PDF DOI 

A biodiversity-crisis hierarchy to evaluate and refine conservation indicators

Authors: Don A Driscoll, Lucie M Bland, Brett A Bryan, Thomas M Newsome, Emily Nicholson, Euan G Ritchie, and Tim S Doherty

Published in: Nature Ecology & Evolution

Abstract

The Convention on Biological Diversity and its Strategic Plan for Biodiversity 2011–2020 form the central pillar of the world’s conservation commitment, with 196 signatory nations; yet its capacity to reign in catastrophic biodiversity loss has proved inadequate. Indicators suggest that few of the Convention on Biological Diversity’s Aichi targets that aim to reduce biodiversity loss will be met by 2020. While the indicators have been criticized for only partially representing the targets, a bigger problem is that the indicators do not adequately draw attention to and measure all of the drivers of the biodiversity crisis.

Here, we show that many key drivers of biodiversity loss are either poorly evaluated or entirely lacking indicators. We use a biodiversity-crisis hierarchy as a conceptual model linking drivers of change to biodiversity loss to evaluate the scope of current indicators. We find major gaps related to monitoring governments, human population size, corruption and threat-industries.

We recommend the hierarchy is used to develop an expanded set of indicators that comprehensively monitor the human behaviour and institutions that drive biodiversity loss and that, so far, have impeded progress towards achieving global biodiversity targets.

Driscoll DA, Bland LM, Bryan BA, Newsome TM, Nicholson E, Ritchie EG, Doherty TS (2018) A biodiversity-crisis hierarchy to evaluate and refine conservation indicators, Nature Ecology & Evolution PDF DOI 

Incorporating disturbance into trophic ecology: fire history shapes mesopredator suppression by an apex predator

Authors: William L Geary, Euan G Ritchie, Jessica A Lawton, Thomas R Healey and Dale G Nimmo

Published in: Journal of Applied Ecology

Abstract

Apex predators can suppress smaller bodied ‘mesopredators’. In doing so, they can provide refuge to species preyed upon by mesopredators, which is particularly important in regions where mesopredators are invasive. While most studies of mesopredator suppression focus on the response of mesopredators to human control of apex predators, other factors –including natural and anthropogenic disturbance – also drive the occurrence of apex predators and, in doing so, might shape spatial patterns of mesopredator suppression.

We examined the role of fire in shaping the occurrence of an apex predator and, by extension, mesopredators and small mammals in a fire-prone region of semi-arid Australia. We measured the activity of an apex predator (the dingo, Canis dingo); an invasive mesopredator it is known to suppress, the red fox (Vuples vuples); and two species of native small mammal (Mitchell’s hopping mouse, Notomys mitchelli; silky mouse, Pseudomys apodemoides) that are potential prey, across 21 fire mosaics (each 12.56 km2). We used piecewise structural equation modelling and scenario analysis to explore the interactions between fire, predators and prey.

We found that dingoes were affected by fire history at the landscape scale, showing a preference for recently burned areas. While foxes were not directly affected by fire history, a negative association between dingoes and foxes meant that fire had an indirect impact on foxes, mediated through dingoes. Despite the suppression of foxes by dingoes, we did not observe a trophic cascade as small mammals were not negatively associated with foxes or positively associated with dingoes.

Synthesis and applications. Disturbance regimes have the capacity to shape patterns of mesopredator suppression when they alter the distributions of apex predators. Environmental change that promotes native predators can therefore help suppress mesopredators – a common conservation objective in regions with invasive mesopredators. The indirect consequences of disturbance regimes should be considered when managing disturbance (e.g. fire) for biodiversity conservation.

Geary WL, Ritchie EG, Lawton JA, Healey TR, Nimmo DG (2018) Incorporating disturbance into trophic ecology: fire history shapes mesopredator suppression by an apex predator, Journal of Applied Ecology PDF DOI 

The Conversation: Australia’s species need an independent champion

By Euan Ritchie (Deakin University), Dale Nimmo (Charles Sturt University), Don Driscoll (Deakin University), Geoffrey Heard (Charles Sturt University), James Watson (The University of Queensland), Megan C Evans (The University of Queensland) and Tim Doherty (Deakin University).

This article was originally published on The Conversation. Read the original article, including reader comments.

Furore erupted last week among many Australians who care for our native species.

First we heard that land clearing in Queensland soared to a staggering 400,000 or so hectares in 2015-16, a near 30% increase from the previous year. Second, the federal government’s outgoing Threatened Species Commissioner, Gregory Andrews, implied on national radio that land clearing was not a pressing issue for Australia’s threatened species.

This is a troubling public message, particularly as the government’s own State of the Environment Report 2016 lists “clearing, fragmentation and declining quality of habitat” as a primary driver of biodiversity decline across the continent.

What’s more, loss of vegetation cover can exacerbate threats to wildlife, by making it easier for cats and other invasive predators to kill native animals.

These comments highlight key issues with the Threatened Species Commissioner’s current remit, made more pressing due to timing: the federal government will soon appoint a new commissioner, a “TSC 2.0”, if you will.

Threatened Species Commissioner 1.0

The commissioner’s role was established in 2014 to address the dire state of threatened species; a key initiative of the then environment minister, Greg Hunt. The remit was sixfold, including bringing a new national focus to conservation efforts; raising awareness and support for threatened species in the community; and taking an evidence-based approach to ensure conservation efforts are better targeted and co-ordinated and more effective.

Did TSC 1.0 meet the objectives?

We can confidently say “yes” in relation to the objectives of collaboration, public awareness and promotion of threatened species conservation. Andrews travelled widely and engaged directly with stakeholders, maintained active social media feeds, developed a YouTube channel, and had numerous media engagements.

Also laudable was the 2015 Threatened Species Summit, attended by some 250 delegates from a diverse set of stakeholders, which garnered significant media coverage.

But elsewhere progress has been mixed. The development of the Threatened Species Strategy is welcome, but the plan does not go nearly far enough. Key targets by 2020 are improvements in the population trajectories of 20 mammals, 20 birds and 30 plants. But this represents a mere 4% of Australia’s threatened species, excluding all threatened reptiles, amphibians, fishes and invertebrates, and most of our threatened flora.

The focus on threatening processes is equally narrow. The science tells us that habitat loss is a top threat to Australia’s biodiversity. Land clearing has been listed as a key threatening process under federal legislation since 2001.

Yet the Threatened Species Strategy mentions land clearing zero times and habitat loss just twice. Feral cats, on the other hand, are mentioned 78 times, with the plan overwhelmingly focused on culling this one invasive species. Other major introduced pests – foxes, rabbits, feral pigs and goats – are mentioned 10 times between them.

An on-ground focus and mobilising of financial and logistical resources to support threatened species recovery was a welcome development during Andrews’s tenure. His second progress report cites AU$131 million in funding for projects in support of threatened species since 2014.

This is a significant sum. But it is just 0.017% of the government’s AU$416.9 billion annual revenue – well short of what’s needed to reverse species declines.

Likewise, funding for threatened species must be better targeted. Of the 499 projects cited in the TSC second progress report, 361 were those of the Green Army and 20 Million Trees programs (costing AU$78 million, 60% of total funding). Neither program is specifically devoted to threatened species, and their benefit in this regard is doubtful.

The next commissioner’s checklist

Australians and democratic societies should have access to reliable, independent and objective information about the current state of our natural heritage, and how government decisions influence its trajectory. That’s a critical role that TSC 2.0 should play.

Expertise will be crucial for the new appointee. Given the complex science of species conservation, a background in environmental science is a clear requirement, just as a background in economics would be expected for the chair of the Productivity Commission, or a grounding in law for a human rights commissioner.

For a commissioner to work effectively, they must also be willing to comment on politically sensitive issues and put themselves at odds with the government when necessary. Commissioners typically work as the head of an independent statutory body, such as the Productivity Commission, the Australian Securities and Investments Commission, and the Australian Electoral Commission.

However, the TSC position sits within the Department of Environment and Energy and so, like any public servant, the commissioner is restricted in what they can say in public forums. A more accurate name for the current position would be Threatened Species Ambassador.

But if the TSC 2.0 is to be a truly informed and independent voice for Australia’s threatened species, the role must sit within a statutory authority, at arm’s length from government. This is the case in New Zealand, where an independent environment commission has operated since 1986. It’s time for Australia to follow suit.
The Conversation

Bayesian networks elucidate interactions between fire and other drivers of terrestrial fauna distributions

Authors: Bronwyn A Hradsky, Trent D Penman, Dan Ababei, Anca Hanea, Euan G Ritchie, Alan York, and Julian Di Stefano

Published in: Ecosphere, volume 8, issue 8 (August 2017)

Abstract

Fire is a major driver of community composition and habitat structure and is extensively used as an ecological management tool in flammable landscapes. Interactions between fire and other processes that affect animal distributions, however, cause variation in faunal responses to fire and limit our ability to identify appropriate fire management regimes for biodiversity conservation.

Bayesian networks (BNs) have not previously been used to examine terrestrial faunal distributions in relation to fire, but offer an alternative statistical framework for modeling complex environmental relationships as they explicitly capture interactions between predictor variables.

We developed a conceptual model of the interactions between drivers of faunal distributions in fire-affected landscapes, and then used a non-parametric BN modeling approach to describe and quantify these relationships for a suite of terrestrial native mammal species. We also tested whether BNs could be used to predict these species’ distributions using only remote-sensed or mapped variables.

Data were collected at 113 sites across 47,000 ha of continuous eucalypt forest in the Otway Ranges, southeastern Australia; time-since-fire (TSF) ranged from six months to 74 years.

Habitat complexity increased with TSF and forest wetness. Critical-weight-range (35–5500 g) marsupials and rodents were generally more likely to occur at long unburnt sites with high habitat complexity, and in wetter forest types. In contrast, large grazers and browsers preferred less complex habitats and younger or drier forest. Species occurrences were more strongly affected by habitat complexity than TSF, coarse woody debris cover, or invasive predator (Vulpes vulpes or Felis catus) occurrence.

Bayesian network models effectively discriminated between the presence and absence of most native mammal species, even when only provided with data on remote-sensed or mapped variables (i.e., without field-assessed data such as habitat complexity). Non-parametric BNs are an effective technique for explicitly modeling the complex and context-dependent influence of fire history on faunal distributions, and may reduce the need to collect extensive field data on habitat structure and other proximate drivers.

Hradsky BA, Penman TD, Ababei D, Hanea A, Ritchie EG, York A and Di Stefano J (2017) Bayesian networks elucidate interactions between fire and other drivers of terrestrial fauna distributions. Ecosphere PDF DOI 

Save Australia’s ecological research

Authors: David B Lindenmayer, Emma L Burns, Christopher, Dickman, Peter T Green, Ary A, Hoffmann, David A Keith, John W, Morgan, Jeremy Russell-, Smith, Glenda M, Wardle, Graeme G R, Gillespie, Saul, Cunningham, Charles Krebs, Gene Likens, Johan Pauw, Tiffany G Troxler, William H McDowell, Jane A Catford, Richard Hobbs, Andrew Bennett, Emily Nicholson, Euan Ritchie, Barbara Wilson, Aaron C Greenville, Thomas Newsome, Rick Shine, Alex Kutt, Ayesha Tulloch, Nicole Thurgate, Alaric Fisher, Kate Auty, Becky Smith, Richard Williams, Barry Fox, Graciela Metternicht, Xuemei Bai, Samuel Banks, Rebecca Colvin, Mason Crane, Liz Dovey, Ceridwen Fraser, Claire Foster, Robert Heinsohn, Geoffrey Kay, Katherina Ng, Chris MacGregor, Damian Michael, Luke, O’Loughlin, Thea, O’Loughlin, Luciana Porfirio, Libby Robin, David Salt, Chloe Sato, Ben Scheele, Janet Stein, John Stein, Brian Walker, Martin Westgate, George Wilson, Jeffrey Wood, Susanna Venn, Michael Vardon, Sarah Legge, Robert Costanza, Danny Kenny, Peter Burnett, Alan Welsh, Joslin Moore, Carla Sgrò, and Mark Westoby

Published in: Science, volume 357, issue 6351 (August 2017)

Australia will lose its integrated long-term ecological research (LTER) network at the end of 2017 (1). The network comprises more than 1100 long-term field plots within temperate forests, rainforests, alpine grass- lands, heathlands, deserts, and savannas, with an unparalleled temporal depth in biodiversity data. Its many achievements include Australia’s first published trend data for key ecosystems (2) and a suite of IUCN ecosystem risk assessments (3).

Long-term ecological data are critical for quantifying environmental and biodiversity change and identifying its causes. LTER is especially important in Australia because many of the country’s ecosystems are subject to frequent climatic extremes. Continuity of long-term research and monitoring, and broader use of existing time series data by science and policy communities, are crucial for measuring impacts of current unprecedented global environmental change and reliably predict- ing future impacts.

Long-term research and monitoring is also essential to understanding relation- ships between the economy, ecosystems, and risks to human well-being (4). The loss of Australia’s LTER network will substantially diminish resource managers’ ability to judge the effectiveness of management interventions on which billions of dollars are spent annually (such as vegetation restoration and invasive species control). Ending the network will also jeopardize sustainability assessments of resource-based industries such as agriculture and forestry. Moreover, Australia’s capacity to participate effectively in global initiatives such as the International LTER will be impaired. The LTER network is part of the Terrestrial Ecosystem Research Network (TERN), funded by Australia’s government (5). TERN’s inclusion of existing LTER capability provided a template that others in Europe, China, and South Africa have followed. Discontinuing the LTER net- work within TERN will therefore undermine global cohesion in environmental research and monitoring.

At a time when the United States is increasing funding for its LTERs by US$5.6M annually (6), and other nations are rapidly building substantial LTER capacity, terminating Australia’s LTER network is totally out of step with interna- tional trends and national imperatives. To prevent the collapse of the LTER network and prevent the resulting irreversible impacts of breaking current time-series, urgent and direct investment by the Australian government is crucial.

  1. TERN, Quarterly Newsletter, Issue 16 (2017); http://www.ozflux.org.au/publications/newsletter/SuperSitesOzFluxCZONewsletter_Issue16_July2017.pdf.
  2. D. B. Lindenmayer, E. Burns, N. Thurgate, A. Lowe, Eds., Biodiversity and Environmental Change: Monitoring, Challenges and Direction (CSIRO Publishing, Melbourne, Australia, 2014).
  3. D. A. Keith, Austral. Ecol. 40, 337 (2015).
  4. D. B. Lindenmayer et al., Austral. Ecol. 40, 213 (2015).
  5. Long Term Ecological Research Network (www.ltern.org.au).
  6. Nature 543, 469 (2017).

Lindenmayer D, et al. (2017) Save Australia’s ecological research. Science PDF DOI