1 June 2014

A three-year national review has found that Australia’s mammal extinction rate is higher than previously thought, and will increase rapidly unless a plan to protect all native species is prioritised.

The Action Plan for Australian Mammals was coordinated over three years by Professor John Woinarski, Dr Andrew Burbidge and Professor Peter Harrison, and draws on the contributions of more than 200 experts. It has found that more than 10% of the country’s endemic species have become extinct since European settlement, and a further 20% of land mammals should now be recognised as threatened.

Professor Woinarski noted that Australia’s mammal extinction rate is the highest in the world, with the rate of extinction continuing more or less unabated since the 1840s. “At least one, and probably two, Australian mammals have been made extinct in the last decade, and if current trends continue, many of the 55 threatened species will disappear within our lifetimes,” Professor Woinarski said.

Even iconic and previously widespread species such as the koala and platypus are now in serious decline.

“Australia’s mammal fauna is the most distinctive in the world. Eighty-six per cent of Australia’s 315 land mammal species occur nowhere else in the world,” Professor Woinarski said.

“People recognise and regret the extinction of the Thylacine [Tasmanian Tiger], but how many Australians could name many of the other mammals lost in the last few generations, like the Lesser Bilby, Toolache Wallaby, Desert Bettong, Long-tailed Hopping-mouse, Crescent Nailtail Wallaby or Pig-footed Bandicoot? We see now only a faint shadow of the richness and abundance of what existed when Europeans arrived in Australia.

“These species were part of the fabric of our country, and they had lived here for at least tens of thousands of years. This scale of loss shows that our society is not fitting well into the land.”

The review analysed the factors most responsible for past and current mammal decline, and concluded that predation by feral cats and foxes was the primary cause of terrestrial mammal decline. Fire, habitat destruction and climate change also play a part.

“If we had to choose one key action to conserve Australia’s biodiversity it would be the control or eradication of feral cats, which currently threaten at least 100 mammal species,” Dr Burbidge said.

The review also considered the status of Australia’s 58 marine mammal species.

“For most of these species it is impossible to assign a conservation status, because so little is known about their population size and trends, threats or ecology. This severely inhibits our ability to manage or conserve them,” Professor Harrison said.

“One welcome finding was that some whales and seals are continuing to increase in numbers and have a more secure conservation status, because bans on whaling and hunting have allowed some species to start recovering from overexploitation.”

The review’s authors believe the analogy of ‘medical triage’, which suggests we should give up on some threatened species, is a defeatist mentality.

“There is hope for Australian mammals. Over recent decades, dedicated management effort has achieved substantial increases in population size for some threatened mammals. If we can control the threats many will bounce back,” Professor Woinarski said.

“In a society as affluent as ours, we have an opportunity to conserve all of our native species, for the benefit and enrichment of future generations. Education and shared obligation are central to this.”

The review was supported by the Australian Wildlife Conservancy, Norman Wettenhall Foundation, Northern Australian Hub of the National Environmental Research Program and the Australian Department of the Environment.

The Action Plan for Australian Mammals is now available through CSIRO Publishing.

Fast facts:

• 29 mammal species have become extinct since European settlement – more than 10% of Australia’s endemic mammal fauna.
• 55 mammal species are now considered threatened – more than 20% of Australia’s land mammal fauna.
• 86% of Australia’s 315 land mammals occur nowhere else in the world.
• Six of Australia’s 58 marine mammal species are known to be threatened but more than half the total species are ‘Data Deficient’ and at least some of these are likely to be declining.
• A few marine mammal species including the humpback whale are recovering from previous whaling.
• The 1,038-page Action Plan includes contributions and peer review by more than 200 experts on Australian mammals.