Category Archives: Publications

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

The Conversation: Scientific integrity must be defended, our planet depends on it

By Euan Ritchie (Deakin University), James Watson (The University of Queensland), Jeremy Kerr, and Martine Maron (The University of Queensland).

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

To conserve Earth’s remarkable species, such as the violet sabrewing, we must also defend the importance of science. Image credit: Jeremy Kerr via The Conversation.

Science is the best method we have for determining what is likely to be true. The knowledge gained from this process benefits society in a multitude of ways, including promoting evidence-based decision-making and management. Nowhere is this more important than conservation, as the intensifying impacts of the Anthropocene increasingly threaten the survival of species.

But truth can be inconvenient: conservation goals sometimes seem at odds with social or economic interests. As a result, scientific evidence may be ignored or suppressed for political reasons. This has led to growing global trends of attacking scientific integrity.

Recent assaults on science and scientists under Donald Trump’s US administration are particularly extreme, but extend far more broadly. Rather than causing scientists to shrink from public discussions, these abuses have spurred them and their professional societies to defend scientific integrity.

Among these efforts was the recent March for Science. The largest pro-science demonstration in history, this event took place in more than 600 locations around the world.

We propose, in a new paper in Conservation Biology, that scientists share their experiences of defending scientific integrity across borders to achieve more lasting success. We summarise eight reforms to protect scientific integrity, drawn from lessons learned in Australia, Canada and the US.

What is scientific integrity?

Scientific integrity is the ability to perform, use and disseminate scientific findings without censorship or political interference. It requires that government scientists can communicate their research to the public and media. Such outbound scientific communication is threatened by policies limiting scientists’ ability to publish, publicise or even mention their research findings.

Public access to websites or other sources of government scientific data have also been curtailed. Limiting access to taxpayer-funded information in this way undermines citizens’ ability to participate in decisions that affect them, or even to know why decisions are being made.

A recent case of scientific information being suppressed concerns the rediscovery, early in 2017, of the plant Hibbertia fumana in New South Wales. Last seen in 1823, 370 plants were found.

Rather than publicly celebrate the news, the NSW Office of Environment and Heritage was reportedly asked to suppress the news until after a rail freight plan that overlapped with the plants’ location had been approved.

Protecting scientists’ right to speak out

Scientists employed by government agencies often cannot discuss research that might relate to their employer’s policies. While it may not be appropriate for scientists to weigh in on policy recommendations – and, of course, constant media commentaries would be chaos – the balance has tipped too far towards restriction. Many scientists cannot publicly refer to their research, or that of others, let alone explain the significance of the findings.

To counter this, we need policies that support scientific integrity, an environment of transparency and the public’s right to access scientific information. Scientists’ right to speak freely should be included in collective bargaining agreements.

Scientific integrity requires transparency and accountability. Information from non-government scientists, through submitted comments or reviews of draft policies, can inform the policy process.

Although science is only one source of influence on policy, democratic processes are undermined when policymakers limit scrutiny of decision-making processes and the role that evidence plays in them.

Let science inform policy

Independent reviews of new policy are a vital part of making evidence-based decisions. There is room to broaden these reviews, inviting external organisations to give expert advice on proposed or existing policies. This also means transparently acknowledging any perceived or actual vested interests.

Australian governments often invite scientists and others to contribute their thoughts on proposed policy. The Finkel Review, for example, received 390 written submissions. Of course, agencies might not have time to respond individually to each submission. But if a policy is eventually made that seems to contradict the best available science, that agency should be required to account for that decision.

Finally, agencies should be proactively engaging with scientific groups at all stages of the process.

Active advocacy

Strengthening scientific integrity policies when many administrations are publicly hostile to science is challenging. Scientists are stuck reactively defending protective policies. Instead, they should be actively advocating for their expansion.

The goal is to institutionalise a culture of scientific integrity in the development and implementation of conservation policies.

A transnational movement to defend science will improve the odds that good practices will be retained and strengthened under more science-friendly administrations.

Many regard science as apolitical. Even the suggestion of publicly advocating for integrity or evidence-based policy and management makes some scientists deeply uncomfortable. It is telling that providing factual information for policy decisions and public information can be labelled as partisan. Nevertheless, recent research suggests that public participation by scientists, if properly framed, does not harm their credibility.

Scientists can operate objectively in conducting research, interpreting discoveries and publicly explaining the significance of the results. Recommendations for how to walk such a tricky, but vital, line are readily available.

Scientists and scientific societies must not shrink from their role, which is more important than ever. They have a responsibility to engage broadly with the public to affirm that science is indispensable for evidence-based policies and regulations. These critical roles for scientists help ensure that policy processes unfold in plain sight, and consequently help sustain functioning, democratic societies.

The authors would like to acknowledge the contribution of Dr Carlos Carroll, a conservation biologist at the Klamath Center for Conservation Research.

The Conversation

Defending the scientific integrity of conservation-policy processes

Authors: Carlos Carroll, Brett Hartl, Gretchen T Goldman, Daniel J Rohlf, Adrian Treves, Jeremy T Kerr, Euan G Ritchie, Richard T Kingsford, Katherine E Gibbs, Martine Maron, and James E M Watson

Published in: Conservation Biology (early view)

Abstract

Government agencies faced with politically controversial decisions often discount or ignore scientific information, whether from agency staff or nongovernmental scientists. Recent developments in scientific integrity (the ability to perform, use, communicate, and publish science free from censorship or political interference) in Canada, Australia, and the United States demonstrate a similar trajectory.

A perceived increase in scientific integrity abuses provokes concerted pressure by the scientific community, leading to efforts to improve scientific-integrity protections under a new administration. However, protections are often inconsistently applied and are at risk of reversal under administrations publicly hostile to evidence-based policy.

We compared recent challenges to scientific integrity to determine what aspects of scientific input into conservation policy are most at risk of political distortion and what can be done to strengthen safeguards against such abuses.

To ensure the integrity of outbound communications from government scientists to the public, we suggest governments strengthen scientific integrity policies, include scientists’ right to speak freely in collective-bargaining agreements, guarantee public access to scientific information, and strengthen agency culture supporting scientific integrity. To ensure the transparency and integrity with which information from nongovernmental scientists (e.g., submitted comments or formal policy reviews) informs the policy process, we suggest governments broaden the scope of independent reviews, ensure greater diversity of expert input and transparency regarding conflicts of interest, require a substantive response to input from agencies, and engage proactively with scientific societies.

For their part, scientists and scientific societies have a responsibility to engage with the public to affirm that science is a crucial resource for developing evidence-based policy and regulations in the public interest.

Carroll C, Hartl B, Goldman GT, Rohlf DJ, Treves A, Kerr JT, Ritchie EG, Kingsford RT, Gibbs KE, Maron M, Watson JEM (2017) Defending the scientific integrity of conservation-policy processes. Conservation Biology, PDF DOI 

Shifting public values and what they mean for increasing democracy in wildlife management decisions

Authors: Lily M van Eden, Chris R Dickman, Euan G Ritchie, and Thomas M Newsome

Published in: Biodiversity and Conservation

Abstract

Over the last century, changing public attitudes about the value of wildlife have triggered substantial changes in species management that have both benefited and hindered conservation efforts. Understanding and integrating contemporary public values is therefore critical for effective conservation outcomes.

Using historic and contemporary examples, we highlight how public attitudes—expressed through the media and campaigns—are shaping the management of introduced and native species, as values shift towards animal welfare and mutualism. We focus on the issue of deliberate human-caused killing of wildlife, because protests against such management have disrupted traditional political and management structures that favoured eradication of wildlife across many jurisdictions and ecological contexts. In doing so, we show that it is essential to work with multiple stakeholder interest groups to ensure that wildlife management is informed by science, while also supported by public values. Achieving this hinges on appropriate science communication to build a better-informed public because management decisions are becoming increasingly democratised.

van Eeden LM, Dickman CR, Ritchie EG, Newsome TM (2017) Shifting public values and what they mean for increasing democracy in wildlife management decisions. Biodiversity and Conservation, PDF DOI