The plan to protect wildlife displaced by the Hume Highway has failed

David Lindenmayer, Australian National University; Martine Maron, The University of Queensland; Megan C Evans, The University of Queensland, and Philip Gibbons, Australian National University


Researchers monitored hundreds of nest boxes used to offset habitat loss. Mason Crane, Author provided

It’s no secret that human development frequently comes at a cost to other creatures. As our urban footprint expands, native habitat contracts. To compensate for this, most Australian governments require developers to invest in biodiversity offsetting, where habitat is created or protected elsewhere to counterbalance the impact of construction. The Conversation

Although biodiversity offsetting is frequently used in Australia – and is becoming increasingly popular around the world – we rarely know whether offsets are actually effective.

That’s why we spent four years monitoring the program designed to offset the environmental losses caused by widening the Hume Highway between Holbrook and Coolac, New South Wales. Our research has found it was completely ineffective.

Map courtesy Google/The Conversation, CC BY-ND

Trading trees for boxes

Wild honeybees occupied many nest boxes.
Mason Crane, Author provided

The roadworks required the removal of large, old, hollow-bearing trees, which are critical nesting sites for many animals, including several threatened species. To compensate for these losses, the developer was required to install one nest box for every hollow that was lost – roughly 600 nest boxes were installed.

Many of the boxes were specifically designed for three threatened species: the squirrel glider, the superb parrot and the brown treecreeper. We monitored the offset for four years to see whether local wildlife used the nest boxes.

We found that the nest boxes were rarely used, with just seven records of the squirrel glider, two of the brown treecreeper, and none of the superb parrot. We often saw all three species in large old tree hollows in the area around the boxes we monitored.

Even more worryingly, almost 10% of the boxes collapsed, were stolen or otherwise rendered ineffective just four years after being installed. Perversely, we found that invasive species such as feral bees and black rats frequently occupied the nest boxes.

The offset clearly failed to deliver the environmental outcomes that were promised. Indeed, researchers have been concerned for some time now that offsetting can be misused and abused.

What can be done?

It’s worth noting that research supports using nest boxes as a habitat replacement. However, they may never be effective for species such as the superb parrot. It’s not quite clear why some animals use nest boxes and others don’t, but earlier monitoring projects in the same area found superb parrots consistently avoid them.


An old hollow-bearing river red gum. Trees like this are vital habitat for many species. Peter Halasz/Wikimedia commons, CC BY-SA

Still, concrete steps can – and should – be taken to improve similar offset programs.

First, the one-to-one ratio of nest boxes to tree hollows was inadequate; far more nest boxes needed to be installed to replace the natural hollows that were lost.

Second, nest boxes clearly cannot compensate for the many other key ecological values of large old trees (such as carbon storage, flowering pulses or foraging habitat). This suggests that more effort is needed at the beginning of a development proposal to avoid damaging environmental assets that are extremely difficult to replace – such as large old trees.There also was no requirement to regularly replace nest boxes as they degrade. It can take a hundred years or more for trees to develop natural hollows suitable for nesting wildlife. To truly offset their removal, thousands of boxes may be required over many decades.

Third, where it is simply impossible to protect key features of the environment during infrastructure development, more holistic strategies should be considered. For example, in the case of the woodlands around the Hume Highway, encouraging natural regeneration can help replace old trees.

Tree planting on farms can also make a significant contribution to biodiversity – and some of these may eventually become hollow-bearing trees. A combination of planting new trees and maintaining adequate artificial hollows while those trees mature might be a better approach.

Being accountable for failure

When an offset program fails, it’s unlikely anyone will be asked to rectify the situation. This is because developers are only required to initiate an offset, and are not responsible for their long-term outcomes.

In the case of the Hume Highway development, the conditions of approval specified that nest boxes were to be installed, but not that they be effective.

Despite the ecological failure of the offset (and over A$200,000 invested), the developer has met these legal obligations.

This distinction between offset compliance and offset effectiveness is a real problem. The Australian government has produced a draft policy of outcomes-based conditions, but using these conditions isn’t mandatory.

The poor results of the Hume Highway offset program are sobering. However, organisations like Roads and Maritime Services are to be commended for ensuring that monitoring was completed and for making the data available for public scrutiny – many agencies do not even do that.

Indeed, through monitoring and evaluation we can often learn more from failures than successes. There are salutary lessons here, critical to ensuring mistakes are not repeated.

David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University; Martine Maron, ARC Future Fellow and Associate Professor of Environmental Management, The University of Queensland; Megan C Evans, Postdoctoral Research Fellow, Environmental Policy, The University of Queensland, and Philip Gibbons, Senior Lecturer, Australian National University

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

New literature on biodiversity offsets from our lab in 2016

More was published about biodiversity offsetting in 2016 than ever before, mirroring the increasing influence of this controversial approach to conservation. Here, we highlight some of the key outputs from our research group working on conservation policy with our collaborators from around the world. Most of these are available freely online but if you’d like a copy email me:

Taming a Wicked Problem: Resolving Controversies in Biodiversity Offsetting

Maron, M., C. D. Ives, H. Kujala, J. W. Bull, F. J. F. Maseyk, S. Bekessy, A. Gordon, J. E. M. Watson, P. E. Lentini, P. Gibbons, H. P. Possingham, R. J. Hobbs, D. A. Keith, B. A. Wintle, and M. C. Evans. 2016. BioScience Biw038

In this review, we sought to summarise the full breadth of challenges faced by biodiversity offsetting – in other words, we asked: why are offsets so polarising? Are they good, bad, or better than nothing? We aimed to provide an accessible overview of the issues being so furiously debated in the world of offsets, including the technical, governance, social and even ethical arguments. Thanks to Joe Bull we were able to include a valuable graphical snapshot of where in the world offsets were happening, and under what guises. We hope this is a valuable go-to paper for those seeking an overview of the messy world of offsetting and a starting point for chasing down key research.

Seeking convergence on the key concepts in ‘no net loss’ policy

Bull, J. W., A. Gordon, J. E. Watson, and M. Maron. 2016.  Journal of Applied Ecology 53:1686-1693.

Offsets, mitigation, compensation…. are all these words interchangeable? And what does ‘no net loss’ actually mean, anyway? Keeping definitions tight and consistent is not just about pedantry; it ensure we are all talking about the same thing, which is pretty important if designing a policy to protect the environment, communicating with the public about the net impacts of a development, or asking developers to spend considerable resources on achieving ‘no net loss’. In this paper, we highlighted a short list of terms that are commonly used in the world of offsets and no net loss, and examine the divergent concepts they have come to be used for. In each case, we suggest a solution to the growing confusion, with reasoning behind each call we have made. My next challenge: to make sure I use the terms consistently myself…

Protecting India’s conservation offsets

Narain, D., and M. Maron. 2016. Science 353:758-758.

Led by Divya Narain, this short article outlines a major risk to the effectiveness of offsets for forest loss in India: lack of additionality. A valid offset must support conservation that would not otherwise happen – you can’t count conservation already planned or under way. But in 2016, the Indian parliament passed laws allowing for funds intended for offsets for forest clearing (compensatory afforestation) to be redirected to a separate afforestation program which forms part of the country’s National Action Plan on Climate Change. In effect, this double counting will mean 1.2 million hectares of deforestation will remain uncompensated for.

A disaggregated biodiversity offset accounting model to improve estimation of ecological equivalency and no net loss

Maseyk, F. J. F., L. P. Barea, R. T. T. Stephens, H. P. Possingham, G. Dutson, and M. Maron. 2016.  Biological Conservation 204, Part B:322-332.

A couple of years ago, Fleur Maseyk led the development of a (voluntary) offset accounting approach for use in New Zealand. One of the important features of that approach was the way in which the different elements of biodiversity that were the focus of the offsets could be disaggregated, ensuring no net loss outcomes for each element. This paper describes this disaggregated model and its development, and notes that despite being designed to estimate biodiversity offset requirements within the largely voluntary New Zealand context, the approach is equally useful for making transparent the set of assumptions behind any offset calculation.

Biodiversity offsetting in dynamic landscapes: Influence of regulatory context and counterfactual assumptions on achievement of no net loss

Sonter, L., N. Tomsett, D. Wu, and M. Maron. 2016. Biological Conservation.

Offset benefits usually take decades to accrue, and data about individual offset trades are often hard to come by, so ex-ante evaluation of offset policies is one of the main ways we can actually work out whether they are likely to achieve no net loss. In work led by Laura Sonter and Nicole Tomsett, we evaluated the current offset approach being used in Queensland, Australia, with a focus on an endangered habitat type (Brigalow woodland). Offsets for the loss of habitat in Queensland are topical, not least because of vast proposed coal mines (such as Adani’s Carmichael mine). We showed how sensitive offset outcomes were to the rates of deforestation that are considered to be ‘business as usual’ – a major issue when Queensland’s land clearing laws and rates change dramatically from government to government. Even so, in none of the scenarios that we examined did the current policy achieve a no net loss outcome for either vegetation extent or bird habitat quality.

Reef Trust Offsets Calculator: A prototype calculation approach for determining financial liability
for marine biodiversity offsets voluntarily delivered through the Australian Government Department of the Environment (Reef Trust)

Martine Maron, Melissa Walsh, Nicole Shumway and Jon Brodie. 2016. Final Report for project 3.12 of the NESP Tropical Water Quality Hub.

Controversial as it may be, development continues to impact on Australia’s Great Barrier Reef Marine Park and World Heritage Area. Because of the nature of the marine and coastal environment, offsets delivered directly by proponents can be particularly challenging. We advised the Australian Government on the development of a tool that could assist potential approval holders and relevant agencies in determining appropriate financial payments as offsets under the Reef Trust. It extended the methodology currently used to calculate terrestrial offsets (which our group led the development of in 2012) to the marine setting. Melissa Walsh is now leading the second phase of this project to develop a working calculator.

Scientists unite against accelerated habitat loss in Australia

This article was first published on the ALERT blog, and describes the recent actions by leading scientists to slow the loss of Australia’s native ecosystems.

Hundreds of senior scientists from across Australia and the world, along with four leading scientific societies, have united to express alarm at Australia’s increasing rate of destruction of native vegetation.

Earlier this month, over 500 scientists met in Brisbane for the Society for Conservation Biology Oceania Section meeting.  Unsurprisingly, one of the hottest topics was habitat destruction.

Declaration Against Habitat Destruction

The delegates of the conference voted to support a scientists’ declaration on land clearing in Australia.  Additional signatories included internationally renowned scientists, including several ALERT members, and ecologists and environmental scientists from across Australia.

“Our native vegetation is crucial to our wildlife, our climate, and the Great Barrier Reef,” said President of the Oceania Section of the Society for Conservation Biology, Professor Richard Kingsford.

“If we continue down this path, the cost to society and the economy will be enormous — and largely irreversible.  We will face higher temperatures, more severe droughts, and see iconic species pushed to extinction”.


Habitat loss threatens most of Australia’s over 1,700 threatened species and ecological communities.

In Queensland, deforestation is returning to globally-significant levels. The scale of the problem has tripled in just three years, with woodland and forest loss at nearly 300,000 hectares per year, according to the government’s latest figures. Continue reading

Submission to the NSW Biodiversity legislation review

Megan Evans and Martine Maron recently made a submission to the New South Wales biodiversity legislation review. You can read our full submission here, and key points are summarised below.

We support efforts to reform native vegetation laws to improve outcomes for biodiversity, reduce regulatory burden where possible, and to create new incentives and opportunities for landholders to engage in private land conservation.

However, we are extremely concerned with particular components of the biodiversity legislation package, which will seriously undermine the object of the Act itself, and run directly counter to the recommendations of the independent review of the Native Vegetation Act 2003.

New South Wales has a significant opportunity to reform its biodiversity and native vegetation laws to enhance positive social, economic and environmental outcomes. The draft Biodiversity Conservation Act in its current form is unlikely to deliver these outcomes. Indeed, in absence of rigorous policy monitoring, evaluation and compliance enforcement, it is not likely we will know what, if any, outcomes the new Act will achieve. Crucially, the many exemptions provided for under the Act will very likely facilitate an increase broad-scale clearing in New South Wales, which would be a significant backward step for environmental policy in Australia.

Continue reading

Better offsets for threatened species

Below is a summary of our NESP-TSR project which Martine Maron, Megan Evans and Fleur Maseyk are involved with.

When species are threatened by development such as urban growth or mining, environmental offsets are often used to help counterbalance the impact.

The idea is to generate an environmental benefit equal to the loss – achieving a neutral net outcome, says Associate Professor Martine Maron from The University of Queensland, who leads the TSR Hub’s ‘Better offsets for threatened species’ Project (5.1).

“Some of the traditional area-based offsets, which may involve creating new habitat and putting protection around it, or restoring the condition of vegetation on other land, can be very expensive but not as effective as we’d hoped,” says Associate Professor Maron.

Flickr_Swift Parrot_heatherw

Image credit: Swift Parrot, courtesy of Heather W (Flickr).

Project 5.1 will explore alternative strategies for providing offset benefits, particularly for threatened species often affected by unavoidable development, such as the Swift Parrot, Regent Honeyeater, Growling Grass Frog and cave-dwelling microbats.

Continue reading

Queensland land clearing is undermining Australia’s environmental progress

Increases in land clearing rates were confirmed in a report released by the Queensland Government late last year. The latest SLATS report, which documents change in woody vegetation in Queensland between 2012-14, shows that the increased rates of clearing are evident across the board: in old-growth vegetation, mature regrowth of threatened ecosystems, and catchments that drain to the Great Barrier Reef – not just young regrowth vegetation. While these land clearing rates increase, they undermine Australia’s environmental programs. Read our recent article in The Conversation here.

Bushfires pushing species to extinction

Climate change is increasing the frequency, severity and extent of bushfires across southern Australia (and in many other parts of the world). Along with Tim Doherty and Rob Davis, Emma Burgess (who has recently graduated form our lab with her PhD) and Martine Maron recently coauthored a story for The Conversation illustrating some of the most recent impacts of bushfires and how the increasing severity is interacting with landscape change to threaten plant and animal species. The paper complements a recent paper by Maron on how increasing climate variability will increase resource bottlenecks for a large range of species globally – see the abstract here and contact if you’d like a reprint.

Postdoctoral position available: better biodiversity offsets for threatened species

We are looking for an outstanding early-career researcher to join our lab as a postdoctoral research fellow. The successful applicant will work collaboratively with a team of people across several universities and organisations in the National Environmental Science Program’s Threatened Species Recovery Hub on the project, “Better offsets for threatened species“.

Offsetting is a relatively new and still-controversial conservation tool. Significant challenges to offset effectiveness for threatened species remain. For example, the vast majority of offsets to date have involved land protection and traditional restoration, which can be expensive, and often have limited and uncertain benefits, which are slow to accrue. This project will identify a suite of Australian threatened species and habitats that most commonly trigger a requirement for offsets, but for which traditional ‘land-based’ offsets are not cost-effective, or for which uncertainty is high. For this suite of species, we will evaluate approaches focussed more directly on threat abatement, including several threat abatement interventions that will be trialled on-ground through linked TSR Hub projects. We will also explore how best to design delivery approaches for such novel offsets, particularly when they require contributions from multiple proponents and investment in threat abatement over the long term.

Click here for all the details on how to apply for this or one of several other postdocs that are now available through The University of Queensland as part of the Threatened Species Recovery Hub. If your interest is in the area of biodiversity offsets, and you have specific questions about the role, you can also contact me by email directly after getting in touch with the central contact person (Hub COO Melanie King). Applications close: 25 Sep 2015 (11:55 PM) E. Australia Standard Time