Australian Geographic: The extinction crisis: Australians call for a radical re-haul of environmental laws

Australia is failing to meet international obligations to protect our unique wildlife, experts say.

Recounting a list of Australian animals on the brink of extinction comes all too easily to Euan Ritchie, an Associate Professor in Wildlife Ecology and Conservation at Deakin University.

“Obvious examples include the orange-bellied parrot, which only has a few individuals left in the wild,” he says, referring to the multi-coloured grass parrot with a total population of less than 50 that migrates between Tasmania and mainland Australia…

Continue reading on the Australian Geographic website

The Conversation: Why the WA government is wrong to play identity politics with dingoes

Western Australian Minister for the Environment Stephen Dawson has declared that the dingo, Australia’s native canine, will no longer be classified as native. Image credit Leo via Flickr.

By Bradley Smith (CQUniversity Australia), Euan Ritchie (Deakin University) and Lily van Eeden, (University of Sydney).

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s Commonwealth Coat of Arms depicts two iconic native animals – the kangaroo and the emu. Both are unquestionably fair dinkum Aussies, unique to this continent and having lived here for a very long time. A “very long time”, according to Australian legislation (the EPBC Act 1999), is any species having been present since before the year 1400.

But in Western Australia, under the state’s Biodiversity Conservation Act 2016, no native animal is guaranteed protection. The Act includes a caveat whereby the relevant minister may determine that a native species is in fact, not.

This week, WA’s environment minister Stephen Dawson did just that, declaring that from January 1, 2019, the dingo, Australia’s native canine, will no longer be classified as native fauna.

The dingo does meet the federal government’s criterion, having lived in Australia as a wild canid for an estimated 5,000 years. But under the planned changes in WA, the dingo will lose its current listing as “unprotected fauna”, and will from next year be considered indistinguishable from either the common domestic dog or feral dogs.

What is a species anyway?

According to the biological species concept, a species is a group that has the ability to interbreed and produce viable, fertile offspring. Dingoes, dogs and other canids do interbreed (or “hybridise”), and indeed this is one of the key reasons why the pure dingo is listed as vulnerable by the International Union for the Conservation of Nature.

But this ability to hybridise is also one of the main justifications cited by the WA government in its decision to revoke the dingo’s citizenship (the fact sheet has since been removed from the website, but can be accessed here). The rationale is that if dingoes and dogs are technically the same species, why should dingoes get special treatment?

However, the biological species concept is problematic when applied to canids. If you lump dingoes and dogs together because they readily interbreed, then logically we must do the same for wolves, coyotes, jackals or other canids that can also interbreed (and have done for millenia).

It’s hard to imagine anyone seriously suggesting that a grey wolf and a pug are the same species. This suggests that this criterion alone is insufficient to solve the conundrum. Indeed, there are at least 32 different species concepts, clearly illustrating the difficulty of defining a single rule by which all organisms should abide.

Despite this, a recent paper that argues the biological species concept should be applied to dingoes, was cited as supporting evidence by the WA government. Adopting this narrow interpretation of taxonomy is perhaps somewhat premature. It ignores other investigations that provide evidence to the contrary. Given the contention around defining species, it seems unwise to determine the species status of dingoes independently of other, more comprehensive evidence and argument.

Distinguishing dingoes

All canids share similarities, but their differences are also many and marked. The dingo can be distinguished from other dogs in various ways: their appearance, anatomy, behaviour, their role in ecosystems, and their genetics (their evolutionary history and degree of relatedness to other species). Dingoes seem to be largely devoid of many of the signs of domestication.

It is therefore reasonable for the dingo to be considered separately from wolves and domestic dogs, while also acknowledging that they all occupy the same broad species classification, Canis lupus.

Having lived in Australia as free-living, wild populations for around 5,000 years almost exclusively under the forces of natural selection, and separately from any other dog lineage until European arrival, there is no notion of the dingo as a domestic animal gone feral. To classify dingoes as nothing more than “feral domestic dogs” expunges their unique, long and quintessentially wild history. Dingoes are not ecologically interchangeable with any other type of dog, either wild or domesticated.

Labelling the dingo as a feral domestic dog changes their legal status and removes any current obligations for developing appropriate management plans. This demotion of status could lead to intensified lethal control. Indeed, control may even be legally mandated.

In the absence of thylacines, mainland Tasmanian devils, and other apex predators, the ecological role that the dingo plays in the Australian landscape is vital. Dingoes help to control kangaroo and feral goat populations, and in some cases foxes and cats as well.

Given WA’s remoteness, it remains one of the few bastions of pure dingoes, and as such it presents an opportunity to seek ways to protect them rather than pave the way for their removal. The WA government’s decision also sets a dangerous precedent for the management of dingoes, and indeed other contentious native wildlife, elsewhere in Australia.

How we choose to classify plants and animals might sound like dry science. But it has genuine implications for policy, management and conservation. Our scientific naming systems are vital for helping to organise and understand the rich biological diversity with which we share the planet, but it is important to remember that these systems are informed not just by biology but also by our values.

In this case, economic and political interests appear to have been favoured over wildlife preservation, and given Australia’s unenviable conservation record this is deeply concerning.
The Conversation

ABC News: Dingoes to remain classified as non-native wild dogs under reform to Western Australian law

Widespread reforms to WA’s Biodiversity Conservation Act, expected next year, will not consider a change to the existing classification of a dingo as a wild dog, not native to Australia.

The iconic animals are considered no different to wild dogs and can be trapped or killed without permission in many places.

Dingoes are currently classed as unprotected native fauna and a declared pest, but the animals will be listed as non-fauna under widespread reform to the Act…

Continue reading on the ABC News website

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

Passing the brumby bill is a backward step for environmental protection in Australia

With the passing of the so-called “brumby bill” against scientific advice, feral horses will continue to damage the internationally significant Kosciuszko National Park.

By Don Driscoll, Euan Ritchie, and Tim Doherty (Deakin University)

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

Late on Wednesday night the so-called “brumby bill” was passed without amendment in the New South Wales Parliament. The controversial Coalition bill, supported by the Christian Democrats and the Shooters, Fishers and Farmers Party, means that feral horses must be kept in Kosciuszko National Park.

It also creates a community advisory panel, with no scientific experts appointed, to advise the minister on how to manage the horse population in the alpine ecosystem.

The NSW government has attracted accusations of a conflict of interest. Former Nationals member Peter Cochran, who now runs a commercial venture offering brumbie-spotting rides through the National Park (and who has donated extensively to Deputy Premier John Barilaro) reportedly commissioned lawyers to draft the bill. Peter Cochran, John Barilaro and Gladys Berejiklian have denied all accusations of conflict of interest and underhanded conduct.

The bill has also been criticised by scientific bodies. In a letter to NSW Premier Gladys Berejiklian this week, the Australian Academy of Science noted that the legislation removes consideration of scientific advice, and called for the bill to be withdrawn or substantially amended.

In a rare move, the International Union for the Conservation of Nature has also written to the NSW government, expressing concern over the potential degradation of this internationally significant national park.

Out of step with other states

The NSW Labor Party does not support the bill and has pledged to repeal the legislation if elected next March. The legislation represents a radical change in NSW’s management of feral horses, coming after a 2016 draft strategy that recommenced reducing their population by 90% over 20 years.

NSW now stands in contrast to other Australian states. Last Saturday, Victoria launched its Feral Horse Strategic Action Plan. That plan aims to protect native species and ecosystems in national parks by removing or controlling feral horses and is a welcome step in the right direction. Victorian environment minister Lily D’Ambrosio called on the NSW and federal governments to support a unified approach to feral horse management in Australia’s alpine regions.

Is culling in or out?

The Victorian plan excludes aerial culling but will revisit horse control methods if the proposed trapping methods don’t reduce environmental impacts. Aerial culling is widely practised throughout Australia, including Western Australia, the Northern Territory, Queensland (where culling was used to improve road safety), and the Australian Capital Territory, which borders Kosciuszko National Park.

Barilaro argued against aerial culling when he presented the Brumby bill to parliament, calling it cruel and barbaric. He reiterated that the bill is meant to prevent lethal control in his response to Victoria’s announcement. But surprisingly, the draft legislation makes no mention of control methods, lethal or otherwise.

The deputy premier also referred to the Guy Fawkes National Park horse cull in northern NSW in 2000 to support his argument against aerial culling. But an independent enquiry found that the cull was an appropriate humane response to the situation, where horses were starving to death and causing environmental damage after a fire. The RSPCA and independent reports show that aerial culling is an acceptable and humane way to manage horse numbers.

Further, the brumby bill now locks in the predictable outcome that thousands of horses are likely to starve to death in the next drought or after large fires. It is therefore puzzling that actions likely to increase horse suffering are not of great concern to many within the pro-brumby lobby.

Greater emphasis, instead, has been put on a cultural argument for protecting feral horses: for example, by claiming that feral horses made enormous contributions to Australia’s World War One effort. However, the cultural heritage report prepared for the NSW National Parks Service says “there is no definitive evidence that remount horses were directly taken from the brumby population of what is now Kosciusko National Park”.

The Sydney Olympics opening ceremony was also offered as evidence that brumbies are integral to Australian culture. However, Australian Stock horses, not brumbies, were showcased at the Sydney Olympics – a distinct breed, established by horse enthusiasts in the 1970s.

That said, it is true that horses in the snowy mountains do have local cultural value. But so too does the native fauna and flora threatened by feral horses, many of which only occur in Australia’s high country. This includes species such as the southern corroboree frog, alpine she-oak skink, broad-toothed rat, Raleigh sedge and mauve burr-daisy.

Can we compromise?

Is a compromise possible, in which both cultural and conservation goals can be accommodated? We think so. The feral horse population can be removed from the national parks and sensitive ecosystems. Brumby herds can thrive on extensive private property in the region, an approach already proven in South Australia’s Coffin Bay National Park.

The brumby bill was written and presented to parliament by groups with at best a perceived conflict of interest, and promoted by using inaccurate information about culling and heritage. It has been roundly criticised by leading national and international scientific bodies for not taking adequate account of science and the key role of national parks in conserving biodiversity.

That this bill has now passed the NSW upper house is a further backward step for conservation goals and Australia’s international reputation for environmental protection, and sets a dangerous precedent by undermining prominent national and state environmental policy. It remains to be seen how this legislation aligns with the federal Environment Protection and Biodiversity Conservation Act, given that it literally tramples over several matters of national environmental significance.

The Conversation