Adorable potoroo on the brink of extinction as Australian bushfires destroy 6 million hectares of its habitat
Approximately 70 nationally threatened species have had at least 50% of their range burnt, while nearly 160 threatened species have had more than 20% of their range burnt, says a new report.
An estimated 99% of the area burned in the devastating Australian fires is a potential habitat for at least one nationally listed threatened species. Accordingly, about six million hectares of threatened species habitat has been burned, say researchers from multiple institutions in Australia.
“To delve deeper into the conservation impact, we used publicly available satellite imagery to look at the burnt areas (up to January 7, 2020) and see how they overlapped with the approximate distributions of all the threatened animals and plants listed under the Environment Protection and Biodiversity Conservation Act. We restricted our analysis to the Mediterranean and temperate zone of the south-east and south-west Australia,” says the report by researchers from The University of Queensland, University of Sydney, and La Trobe University, published in The Conservation.
The current study says approximately 70 nationally threatened species have had at least 50% of their range burnt, while nearly 160 threatened species have had more than 20% of their range burnt.
Many animals and plants have been incinerated or suffocated by smoke and ash. Others may have escaped the blaze only to die of exhaustion or starvation, or be picked off by predators.
More than 50% of the habitat of several species known to be susceptible to fire has been burnt, which includes the long-footed potoroo and Littlejohn’s tree frog.
“For fire-sensitive threatened species, these fires could have substantially increased the probability of extinction by direct mortality in the fires or reducing the amount of suitable habitat,” say researchers.
Other species that have been severely impacted include the Kangaroo Island dunnart and the Kangaroo Island glossy black cockatoo. “These species’ entire populations numbered only in the hundreds before these bushfires that have burned more than 50% of their habitat,” says the research team.
Glossy black cockatoos have a highly specialized diet: they eat the seeds of the drooping sheoak (Allocasuarina verticillata). According to the researchers, these trees may take anywhere from 10 to 50 years to recover enough to produce sufficient food for the black cockatoos.
The figures do not account for the cumulative impacts of previous fires. For example, the critically endangered western ground parrot had around 6,000 hectares of potential habitat burnt in these fires, which exacerbates the impact of earlier extensive fires in 2015 and early 2019.
The researchers caution that the number of species affected and the extent of the impact might change since many fires are still burning.
“What we do know is that these species are already on the brink of extinction due to other threats, such as land clearing, invasive species, climate change, disease, or previous fires,” they say.
Australia supports a rich and impressive diversity of mammals, with over 300 native species. Some 34 species and subspecies of native mammals have become extinct in Australia over the last 200 years, the highest rate of loss for any region in the world.
In an estimate released on January 8, Professor Dickman, from the University of Sydney’s Faculty of Science had said that more than one billion animals have been killed in Australian bushfires.
The researchers of the current study say more threatened plants have been affected than other groups: 209 threatened plant species have had more than 5% of their range burnt compared to 16 mammals, 10 frogs, six birds, four reptiles and four freshwater fish.
“Twenty-nine of the 30 species that have had more than 80% of their range burnt are plants. Several species have had their entire range consumed by the fires, such as the Mountain Trachymene, a fire-sensitive plant found in only four locations in the South Eastern Highlands of NSW,” says the report.
According to the experts, the populations of many species will need “careful management and protection” to give their habitats enough time to recover and re-supply critical resources.
“After the embers settle, with enough investment and conservation actions, guided by evidence-based science, it may be possible to help threatened species recover,” say researchers.
The experts recommend that management of threatening processes such as weeds, feral predators, introduced herbivores, and habitat loss through logging or thinning must occur both at key sites as well as across the landscapes they sit in. “Maintaining only small pockets of habitat in a landscape of destruction will lock many species on the pathway to extinction,” the team explains.
They say in some cases, rigorous post-fire restoration will be necessary to allow species to re-colonize burnt areas. “This may include intensive weed control and assisted regeneration of threatened flora and specific food sources for fauna, installing nest boxes and artificial cover, or even targeted supplementary feeding,” says the research team.