Australia’s ‘Ecological Axis of Evil’ triggers native mammal collapse

Dr Mark Ziembicki of James Cook University in Australia has spent much of the last several years chasing an environmental mystery -- the cause of the dramatic collapse of mammal populations in northern Australia.  Here he gives us an update on an emerging biodiversity crisis:

Across the world, biodiversity is being battered by familiar foes.  Habitat loss, overexploitation, invasive species, and impacts of human development are leading us to what many believe may be the sixth great extinction.

A northern quoll.  This native marsupial 'cat' is suffering greatly in northern Australia.

A northern quoll.  This native marsupial 'cat' is suffering greatly in northern Australia.

In contrast to the environmental pressures on other continents, large parts of Australia have undergone only limited modification, and are sparsely settled and remote.  Many areas have substantial nature reserves.

Yet, nonetheless, Australia has the world’s worst record for contemporary mammal extinctions.  One in ten species have disappeared in the last 200 years -- and of those that persist, over a third are now threatened or near threatened.  What’s more, recent analyses suggest the problem is even worse than previously thought.

Greater recent recognition of Australia’s ‘extinction calamity’ and its spread to the tropical north (see here, here and here) has provoked intense interest and stimulated a series of research and management initiatives to study the declines, their causes, and what can be done to halt them.

A new paper I published with a team of coauthors summarizes the research efforts, and assesses the effectiveness of recent conservation-management interventions.

In our view, the loss of Australia’s mammals has been driven primarily by what has been dubbed Australia’s Ecological Axis of Evil -- an unholy trinity comprising the feral cat, altered fire regimes, and grazing impacts.

Just ask George... a conceptual model for an 'Ecological Axis of Evil'

Just ask George... a conceptual model for an 'Ecological Axis of Evil'

Alone, these threats do not explain the declines but there is now some compelling evidence that, when operating in concert, predation by feral cats exacerbated by frequent, intense fires, reduced ground cover from overgrazing, and, in some areas, the control of dingoes are driving the declines.

So what’s to be done?  The demonstration of interacting factors gives conservation managers some options for reducing their impacts.  There are now some examples of rapid recovery of species following threat management.

Priority actions include intensively managing fires, reducing feral livestock in conservation reserves, establishing exclosures to keep feral predators out, enhancing biosecurity for important islands where rare species still persist, and acquiring grazing lands in important mammal areas for conservation purposes.

Despite some progress, we still have much to learn and even more to do, to stop and reverse the devastating declines. 

Equally worrying is that Australia's federal and state governments are planning an ambitious expansion of agriculture, grazing, roads, energy, and irrigation projects in northern Australia.  These developments are likely to intensify threats that have so far been limited in the region, but that have caused much biodiversity loss in other parts of the world.

This is a dangerous time for Australia's biodiversity.  Without effective planning and management actions, a significant component of northern Australia’s mammal fauna could collapse -- contributing further to the continent’s already-woeful record for mammal extinctions.

Australia's shame: World Heritage sites in peril

The world is struggling to protect its most crucial natural areas.  Poorer countries are faring the worst, but even a wealthy nation like Australia isn't doing very well.

Iconic species in trouble... the white lemuroid possum, found only in the Queensland Wet Tropics, was driven to the edge of extinction by a 2005 heat wave  (photo (c) Jonathan Munro)

Iconic species in trouble... the white lemuroid possum, found only in the Queensland Wet Tropics, was driven to the edge of extinction by a 2005 heat wave (photo (c) Jonathan Munro)

In total, 156 sites on the World Heritage List are recognized for their outstanding biodiversity values -- they protect parts of 31 of the world's 35 biodiversity hotspots, and a portion of all of its high-biodiversity wilderness areas.

But the first World Heritage Outlook Report -- released last week at the World Parks Congress in Sydney, Australia -- found that many of these sites are struggling.  Nearly a tenth (8%) are in critical condition, and nearly a third (29%) of 'significant concern'.

Unfortunately for global biodiversity, many of the critical sites are tropical forests.  These include Virunga National Park in the Democratic Republic of Congo -- home to the iconic mountain gorilla -- and the Tropical Rainforests Heritage of Sumatra, Indonesia, the last place on Earth where orangutans, tigers, elephants, and rhinos still coexist.

Also in critical condition is Salonga National Park in the Democratic Republic of Congo, a key refuge for bonobos, the smaller and remarkably placid cousins of chimpanzees.

Developing nations face many governance, economic, and social disadvantages that are creating profound challenges for nature conservation.

But even in wealthy, stable Australia, the picture is not good.  For example, the World Heritage Committee has repeatedly threatened to declare the Great Barrier Reef a World Heritage Site in Danger.

And the Wet Tropics of Queensland World Heritage Area is in the 'significant concern' category.  The site -- renowned for its unique biodiversity and cultural values -- faces a battery of threats, including its extreme vulnerability to climate change, scores of invasive species, growing threats from infrastructure and urbanization, and other perils.

Remarkably, research published last year in the leading journal Science rated the Queensland Wet Tropics the second most irreplaceable World Heritage site globally for its outstanding biodiversity values. 

There be dragons... a Boyd's forest dragon, another unique denizen of the Queensland Wet Tropics  (photo (c) Martin Cohen)

There be dragons... a Boyd's forest dragon, another unique denizen of the Queensland Wet Tropics (photo (c) Martin Cohen)

Notably, World Heritage magazine recently identified the Queensland Wet Tropics site as one of six 'Best Practice' examples globally.  So why is the site now perceived to be in so much danger?

In short, politics.  Both the federal government in Australia and the state government of Queensland are not considered conservation-friendly.  As a result, the Wet Tropics Management Authority, which is responsible for managing and protecting the Queensland rainforests, has been paralyzed.

The board currently has no budget, and only two of its six required non-Executive Board Members.  The federal and Queensland governments have decided not to make any new Board appointments until a Queensland government “review” of World Heritage management.

The news gets worse.  The federal government is now proposing to greatly weaken environmental impact assessments in Queensland.  One shudders to think about the potential implications.

If the Australian and Queensland governments continue down this path, one of the world's most important natural areas could face even greater perils. 

It’s time for the Australian and international communities to demand action from Australia's political leaders.  It's simply shameful to play political football with a site of such outstanding natural and cultural values -- a site that increasingly appears to be in imminent danger.