PhD scholarships: The effects of fire on biodiversity in north-central Victoria
Charles Sturt University, Albury, NSW
Stipend: $26,288 (tax free) per year over 3 years plus a $5,000 top up.
An opportunity exists for a student to undertake a PhD on the effects of fire on biodiversity in the Strathbogie ranges of north-east Victoria. The project will be supervised by Dr Dale Nimmo of the Institute of Land, Water and Society (ILWS) and the School of Environmental Science. Focal taxonomic groups could include mammals, birds, reptiles, plants (with co-supervision from Dr Jodi Price, CSU), or pollinators (with co-supervision from Dr Manu Saunders, CSU).
The project is supported by the Goulburn Broken CMA (Dr Jenny Wilson) and the Department of Environment, Land, Water and Society (Dr Jane Roots), with substantial opportunity for industry engagement.
As well as an annual stipend ($31,288 including top up) and considerable in-kind support, the student will have access to operating funds ($5,000 per year) to support travel and fieldwork.
Applicants must apply through Charles Sturt University for a relevant scholarship for doctoral studies e.g. Australian Post Graduate Award (APA) or CSU University Postgraduate Research Scholarship. Further details are at: http://www.csu.edu.au/research/scholarships
Potential candidates will need a First Class Honours, Masters degree with a research component, or equivalent.
Please contact Dr Dale Nimmo for further information: email: email@example.com (phone: 02 6051 9827).
Originally published on The Conversation. By Tim Doherty, Dale Nimmo, Al Glen, Euan Ritchie and Chris Dickman.
Invasive species are a threat to wildlife across the globe – and invasive, predatory mammals are particularly damaging.
Our research, recently published in Proceedings of the National Academy of Sciences, shows that these predators – cats, rats and foxes, but also house mice, possums and many others – have contributed to around 60% of bird, mammal and reptile extinctions. The worst offenders are feral cats, contributing to over 60 extinctions.
So how can we stop these mammals eating away at our threatened wildlife?
Counting the cost
Our study revealed that invasive predators are implicated in 87 bird, 45 mammal and 10 reptile extinctions — 58% of these groups’ contemporary extinctions worldwide.
Invasive predators also threaten 596 species classed as vulnerable, endangered or critically endangered on the International Union for the Conservation of Nature Red List. Combined, the affected species include 400 birds, 189 mammals and 149 reptiles.
Twenty-three of the critically endangered species are classed as “possibly extinct”, so the number of extinctions above is likely to be an underestimate.
Until now, these shocking statistics have been unknown, and the heavy toll of invasive predators on native biodiversity grossly underappreciated. Species extinctions attributed to invasive predators include the Hawaiian rail (Zapornia sandwichensis) and Australia’s lesser bilby (Macrotis leucura).
Who are the worst offenders?
We found that three canids (including the red fox and feral dogs), seven members of the weasel family or mustelids (such as stoats), five rodents, two primates, two mongooses, two marsupials and nine species from other families negatively impact threatened species. Some of these species, such as hedgehogs and brushtail possums, don’t immediately spring to mind as predators, yet they are known to prey on many threatened species.
Feral cats threaten the most species overall (430), including 63 that have become extinct. This equates to one-quarter of all bird, mammal and reptile extinctions – making the feral cat arguably the most damaging invasive species for animal biodiversity worldwide.
Five species of introduced rodent collectively threaten 420 species, including 75 extinctions. While we didn’t separate out the impacts of individual rodent species, previous work shows that black rats (Rattus rattus) threaten the greatest number of species, followed by brown rats (R. norvegicus) and Pacific rats (R. exulans).
The humble house mouse (Mus musculus) is another interesting case. Despite their small size, house mice have been recorded eating live chicks of albatrosses, petrels and shearwaters.
Other predators that threaten large numbers of species are the domestic dog (Canis familiaris), pig (Sus scrofa), small Indian mongoose (Herpestes auropunctatus), red fox (Vulpes vulpes) and stoat (Mustela erminea).
Island species most at risk
Species found only on islands (insular endemics) account for 81% of the threatened species at risk from predators.
The isolation of many islands and a lack of natural predators mean that insular species are often naive about new predators and lack appropriate defensive responses. This makes them highly vulnerable to being eaten and in turn suffering rapid population decline or, worse, extinction. The high extinction rates of ground-dwelling birds in Hawaii and New Zealand — both of which lack native mammalian predators — are well-known examples.
Accordingly, the regions where the predators threatened the greatest number of species were all dominated by islands – Central America and the Caribbean, islands of the Pacific, the Madagascar region, New Zealand and Hawaii.
Conversely, the continental regions of North and South America, Europe, Africa and Asia contain comparatively few species threatened by invasive predators. While Australia is a continent, it is also an island, where large numbers of native birds and mammals are threatened by cats and foxes.
Managing menacing mammals
Understanding and mitigating the impact of invasive mammal predators is essential for reducing the rate of global biodiversity loss.
Because most of the threatened species studied here live on islands, managing invasive predators on islands should be a global conservation priority. Invasive predators occur on hundreds of islands and predator control and eradication are costly exercises. Thus, it is important to prioritise island eradications based on feasibility, cost, likelihood of success and potential benefits.
On continents or large islands where eradications are difficult, other approaches are needed. This includes predator-proof fencing, top-predator restoration and conservation, lethal control, and maintenance of habitat structure.
Despite the shocking statistics we have revealed, there remain many unknowns. For example, only around 40% of reptile species have been assessed for the Red List, compared to 99% for birds and mammals. Very little is known about the impact of invasive predators on invertebrate species.
We expect that the number of species affected by invasive predators will climb as more knowledge becomes available.
This article was co-authored by Al Glen from Landcare Research, New Zealand. Landcare Research is a government-funded research organisation that conducts research into a range of conservation issues, including pest management. It did not provide funding for this research
I’m excited to say that the Hermon Slade Foundation has thrown support behind my research for a second consecutive year. Last year it was for a project examining the long-term recovery of woodland bird communities following southern Australia’s Millennium Drought (2001-2009), building on previous work in the region that documented shorter-term responses (see here, here,here, and a perspective piece it inspired here).
This time it is to initiate a study on the capacity for traditional Indigenous fire management to restore mammal communities. The project is in collaboration with Rebecca and Doug Bird from the Human Environmental Dynamics Lab at Penn State, USA, and Euan Ritchie from Deakin University. We will work in remote parts of the Western Desert of Western Australia, where Rebecca and Doug have done ground-breaking work (see here, here, here) on the fire regimes maintained by Indigenous communities and their impacts on native species. We will compare areas under active Indigenous fire management with areas where such management has long ceased to reveal the ecological consequences of an active, traditional fire regime. We are extremely grateful to the Hermon Slade Foundation for supporting this work, and I can’t wait for this collaboration to begin later in the year.
A new paper from PhD student Mark Hall. This is actually Mark’s honours work, so it’s great to see it published (far too few honours theses make it to publication). Well done Mark!
In agricultural regions worldwide, linear networks of vegetation such as hedges, fencerows and live fences provide habitat for plant and animal species in heavily modified landscapes. In Australia, networks of remnant native vegetation along roadsides are a distinctive feature of many rural landscapes. Here, we investigated the richness and composition of woodland-dependent bird communities in networks of eucalypt woodland vegetation along roadsides, in an agricultural region in which >80% of native woodland and forest vegetation has been cleared. We stratified sites in a) cross sections and b) linear strips of roadside vegetation, to test the influence on woodland birds of site location and configuration in the linear network (the ‘intersection effect’). We also examined the influence of tree size at the site, the amount of wooded vegetation surrounding the site, and the abundance of an aggressive native species, the noisy miner Manorina melanocephala. Birds were surveyed at 26 pairs of sites (cross section or linear strip) on four occasions. A total of 66 species was recorded, including 35 woodland species. The richness of woodland bird species was influenced by site configuration, with more species present at cross sections, particularly those with larger trees (>30 cm diameter). However, the strongest influence on species richness was the relative abundance of the noisy miner. The richness of woodland birds at sites where noisy miners were abundant was ~20% of that where miners were absent. These results recognise the value of networks of roadside vegetation as habitat for woodland birds in depleted agricultural landscapes; but highlight that this value is not realised for much of this vast vegetation network because of the dominance of the noisy miner. Nevertheless, roadside vegetation is particularly important where the configuration of networks create nodes that facilitate movement. Globally, the protection, conservation and restoration of such linear networks has an important influence on the persistence of biota within human-dominated landscapes.
I’ve recently been hopeful about a possible revival of landscape-scale research. To me, conservation science went a bit like this: general principles were being established in the 1960; reserves were advocated in the 1970s; reserve planning was perfected in the 80s and 90s; the “matrix” outside protected areas attracted attention in the 1990s, along with a rise in landscape ecology; ecosystem services arose as a new field of enquiry in the 2000s; and protected areas…
Unfortunately, mass coral bleaching is just one example of a far broader problem. Although it represents a rapid and extensive example of ecosystem degradation, coral bleaching is not surprising: it is consistent with many changes that are occurring now across Australia’s natural environments.
Our iconic trees – including the world’s tallest flowering plant, the Mountain Ash, and the most widely distributed eucalypt, the River Red Gum – are among the hardest hit.
A stark example is the floodplain forests of the Murray-Darling Basin. Reduced rainfall and water extraction for human needs have deprived River Red Gums of the flooding integral to their existence. The consequence is that 79% of forests on the Murray River have dieback. Tree graveyards are a common sight.
On the back of historic declines (primarily due to land clearing), two-thirds of species declined substantially as the drought took hold. The assumption, or perhaps hope, was that these declines were part of a natural cycle, and that the drought’s end would bring a return to normal. This did not happen.
The result is that our bird communities have dramatically changed in as little as two decades. As we enter another period of drying, there is grave concern about the future of southern Australia’s birds.
What do Australians value?
These are just a few examples of massive ecosystem degradation. Sadly, there are many more. The battle for Australia’s biodiversity can still be won, but this requires decisive action on climate change and serious investment over many election cycles.
The budget allocation for the federal Department of the Environment is shrinking and is now less than 0.5% of the government’s spending. It is hard not to draw comparisons with the recent announcement that Australia will spend A$50 billion on submarines.
By contrast, avoiding extinctions of Australian birds would cost around A$10 million per year — a cost we are, at the moment, unwilling to meet.
“Don’t tell me what you value; show me your budget, and I’ll tell you what you value.”
On May 3, Australia’s government will present its 2016 budget and, with an election looming, we will also soon learn about the opposition’s spending commitments. The coming months will expose how major parties value Australia’s environment, and the election to follow will measure the degree to which Australians accept it.