When Australia was settled by Europeans, about 180 species of mammals lived in the northern savannahs of the continent. The landscape teemed with animals, from microbats to rock-wallabies and northern quolls. Many of these mammals have not been found anywhere else on Earth.
An unidentified account from the Normanton district in northwest Queensland, dating from 1897, recounts the abundance:
“There were thousands of millions of these rats (Rattus villosissimus), and as most Gulf identities remember, after them came a plague of native cats (the Quoll of the North).
These extended from 18 miles west of the Flinders (river) to less than 40 miles from Normanton, and they cleaned out all of our tucker.
But tragically, in the years that followed, many of these mammals disappeared. Four species have disappeared and nine will suffer the same fate over the next two decades.
And we know relatively little about this local crisis. Monitoring of these species has been lacking for many decades – and as mammal numbers have declined, knowledge gaps have widened.
A precipitous decline
Australia’s Northern Savanna includes the upper half of Queensland and the Northern Territory and the upper quarter of Western Australia. It covers 1.9 million square kilometres, or 26% of Australia’s landmass.
Species already extinct in northern Australia are:
- burrow betong
- Nabarlek of the Victoria River District (possibly extinct)
- capricorn rabbit-rat
- Melomys of Bramble Cay.
Northern Australian species identified as being at risk of becoming extinct within 20 years are:
- northern jumping mouse
- carpenter rock rat
- black-footed tree rat (Kimberley and Top End)
- High-end Nabarlek
- Kimberley’s brush-tailed phascogale
- brush-tailed rabbit-rat (Kimberley and Top End)
- northern brush-tailed phascogale
- Tiwi Islands brush-tailed rabbit-rat
- betong from the north.
Many other mammal species have been added to the endangered species list in recent years, including koalas, northern spot-tailed quolls and spectacled flying foxes.
So what is causing the decline? For some animals, we don’t know the exact reasons. But for others, they include global warming, pest species, altered fire regimes, grazing by introduced herbivores, and disease.
Read more: Our laws have failed every moment in the face of these endangered flying foxes. On Saturday Cairns Council will put another nail in the coffin
Follow-up is crucial
There is no doubt that some northern Australian mammal species are heading towards extinction. But information is limited because the monitoring of these populations and their ecosystems is sorely lacking.
Monitoring is crucial for species conservation. It allows scientists to protect an animal’s habitat and understand the rate of decline and the processes that drive it.
Our research revealed that much of northern Australia lacks species or ecosystem monitoring.
Monitoring primarily involves long-term projects in three National Parks in the Northern Territory. Mammal trends in the region must be estimated from these few sites.
More recent monitoring sites have been established in the Kimberley in Western Australia. There are very few wildlife monitoring programs in the Queensland savannahs.
Lack of monitoring hampers conservation efforts. For example, researchers do not know the status of the Queensland tree rat subspecies because the species is not monitored at all.
Research and monitoring efforts have declined significantly over the past two decades. Reasons for this include, but are not limited to:
a massive reduction in federal environmental funding since 2013 and substantial reductions in environmental funding for some states and territories
reduced capacity of government institutions dedicated to research on ecosystems and species
the existence of only two universities in northern Australia with a focus on ecological research
a reliance on remote sensing and vegetation condition monitoring, which does not detect animal trends.
Read more: Australia’s endangered species plan has failed on several counts. Without change, more extinctions are assured
The Lesson of Bramble Cay Melomys
A flurry of research shows increasing rates of animal population declines and extinctions. Australia has the worst mammal extinction rate of any country.
Yet Australian governments have largely stayed on their heels as the biodiversity crisis deepens.
A Senate committee was tasked in 2018 to investigate Australia’s wildlife extinctions. It has not yet produced its final report.
In September last year, the Federal Environment Ministry announced that 100 “priority species” would be selected to help focus recovery actions. But more than 1,800 species are listed as threatened in Australia. Prioritizing just 100 is unlikely to help the rest.
The lack of monitoring of endangered species in Australia creates a political banner that prevents vital action to prevent extinctions.
Nowhere is this truer than in the case of Bramble Cay Melomys. The nocturnal rodent was confirmed extinct in 2016 due to flooding of its home island in the Torres Strait caused by global warming.
The species had previously been recognized as one of the rarest mammals on Earth – but a plan to recover its numbers was never properly implemented.
A crisis before our eyes
Conservation scientists and recovery teams work across northern Australia to help species and ecosystems recover. But they need resources, policies and a long-term commitment from governments.
Indigenous guardians working on the land can provide important skills and resources to save species. If traditional owners could combine forces with non-indigenous researchers and conservation managers – and with the right support and incentives – we could gain ground.
Indigenous protected areas, national parks and private conservation areas provide some protection, but this network needs to be expanded.
We propose to establish a network of monitoring sites by prioritizing particular bioregions – large, geographically distinct tracts of land with common characteristics.
Building a network of monitoring sites would not only help prevent extinctions, but would also support livelihoods in remote parts of northern Australia.
The policies driving investment research and tracking need to be reset and new approaches implemented urgently. Basically, the funding must be sufficient for the task.
Without these measures, more species will disappear on our watch.