The Morrison government has formally recognised the extinction of a tiny island rodent, the Bramble Cay melomys - the first known demise of a mammal because of human-induced climate change.
The changed status of the Melomys rubicola from the government's "endangered" to "extinct" category was included without fanfare in a statement released by federal Environment Minister Melissa Price late on Monday.
Geoff Richardson, an environment department official, told Senate estimates on Monday night that research efforts since 2014 - "including a pretty rushed trip in 2015" - had failed to identify any melomys individuals in their only known location on Bramble Cay, a tiny Torres Strait island near Papua New Guinea .
Declaring its extinction "was not a decision to take lightly," Mr Richardson said. "There's always a delay while the evidence is gathered to be absolutely certain."
The federal extinction listing comes almost three years after the Queensland government reached a similar conclusion, with a finding that the demise of the melomys "probably represents the first recorded mammalian extinction due to anthropogenic climate change".
The limited range of the animal, living on a five-hectare island less than three metres high, left it vulnerable to climate change. However, its 2008 "recovery plan", drawn up when numbers were likely down to just dozens of individuals, downplayed the risks.
"[T]he likely consequences of climate change, including sea-level rise and increase in the frequency and intensity of tropical storms, are unlikely to have any major impact on the survival of the Bramble Cay melomys in the life of this plan," the five-year scheme stated.
The federal policy director for the Wilderness Society, Tim Beshara, said preparation for the plan was limited, and it was never reviewed at its completion in 2013.
“The Bramble Cay melomys was a little brown rat," Mr Beshara said. "But it was our little brown rat and it was our responsibility to make sure it persisted. And we failed."
Kylie Jonasson, another department official, told estimates that "we could have engaged sooner in the case of the [melomys] with the Queensland government, or vice versa".
Leeanne Enoch, Queensland's Environment Minister, said the animal's extinction showed "we are living the real effects of climate change right now".
“We have consistently called on [Prime Minister] Scott Morrison and Melissa Price to show leadership on climate change, instead of burying their heads in the sand," Ms Enoch said. “How many more
species do we have to lose for the federal government to take action?”
Minister Price said it was "incredibly disappointing when any species is formally declared extinct, and everybody has feared the worst for some time, given the Bramble Cay melomys hasn’t been sighted since 2009.
"Our agencies will continue to focus their efforts on protecting species identified as priorities, supported by the Government’s $425 million investment in threatened species programs," she said.
Greens Senator Janet Rice, chair of the Senate inquiry into Australia's animal extinction crisis, said the country already had the worst mammalian extinction rate in the world, and one of the highest overall extinction rates.
"Business as usual is the death warrant for our threatened animals," Senator Rice said, noting the spectacled flying fox was the latest species moved into the endangered category in Monday's update.
"The extinction of the Bramble Cay Melomys should be a national tragedy, and the Morrison government’s failure to protect Australia’s nearly 500 animals threatened with extinction is an absolute disgrace," she said.
"The environment department says it’s learnt from this extinction and takes extinction seriously, but if it was serious it should be conducting an immediate review of how this happened," she said.
John Woinarski, a professor at Charles Darwin University who has published research on the melomys, said failure to assign primary responsibility to one agency appears to be a critical factor in the animal's demise.
“Respective officials didn’t understand the urgency," and how predictable and preventable the extinction was, he said.
“It should be mandatory whenever there is an extinction that there be the equivalent of coronial inquest to figure out the cause, the failings and to develop the systematic improvements so the problems are not repeated," Professor Woinarski said.
One of the main challenges is that much of the loss of biodiversity in Australia is in remote areas, where the threatened species have "a low public profile" and lack the charisma of animals like koalas.
Another is that conservation programs are prone to "fickle" funding cycles when we need to work on decades or generational scales, Professor Woinarski said.
Much of the loss of biodiversity is in remote areas, with low public profile and charisma.
Tony Burke, federal Labor's environment spokesman, said the end of the melomys was "a stark reminder of the need for strong environmental laws".
"It is not enough to put a species on a list," Mr Burke said. "The recovery plan needs to be properly designed, enforced and regularly updated."