More than 14,000 species of invertebrates lost their habitat during Australia’s 2019-20 bushfires, according to a post-fire analysis that recommended doubling the number of threatened species.
the research, created for the federal government by scientists from the National Environmental Science Program (NESP), found that the number of insects, spiders, worms and other invertebrates affected by the disaster was much greater than the number of vertebrates affected.
However, this fact has been largely overlooked due to the focus on more popular animals like the koala.
The NESP study warns that the real number is likely to be well above 14,000, given that so many Australian invertebrates are either undescribed or no data are available to measure declines.
At least one animal, the Banksia montana mealybug in Western Australia, is believed to be likely extinct due to the Black Summer fires in that state.
“If you look at the animals hardest hit by the fires, about 95% of them are invertebrates,” said John Woinarski, a professor at Charles Darwin University and one of the study’s authors. “And it got very little publicity.”
Australia has 111,233 described terrestrial and freshwater invertebrate species. Although they receive less attention than Australia’s unique mammals and birds, they perform important functions in the ecosystem, such as pollination or as a food source for larger animals.
Others are detritivors, which break down ecosystem debris – like leaf litter – which return nutrients to the soil, encourage plant growth, and reduce fuel loads for fires.
Scientists were able to use existing records and fire maps to compile enough data for 32,164 invertebrates, while discovering that for some species they were working with only a record or two of their existence were known.
The scientists found that 14,159 – roughly half of these species – had at least some of their habitat burned by the fires, with 1,209 having either 50% of their known range burned by fires of any severity or 30% by high intensity fires.
Of those 1,209, scientists had enough data to recommend the government add 60 species to Australia’s Nationally Endangered Invertebrate List, which currently includes 63.
Jess Marsh, a researcher on Kangaroo Island and co-author of the study, said the 60 she recommended for listing were “just the ones we know” – meaning there was enough data available to them to question for assessment by the threatened Scientific Committee on Species.
It is the responsibility of the committee to examine these species before issuing a recommendation to the federal government as to whether they should be classified as threatened under the Environmental and Species Protection Act.
“Many of the species that are likely to be most endangered are out of the question because there isn’t enough data,” Marsh said.
Among the invertebrates recommended for listing by scientists were the Kangaroo Island killer spider, a centipede of the genus Atelomastix in Western Australia and a species of caddis fly found in New South Wales and Victoria, the larvae of which live in water and are sensitive to chemical changes caused by fire.
Marsh has been researching the Kangaroo Island killer spider for several years. It is one of several ancient types of assassins found in Australia and so named because they eat other spiders. They are sometimes referred to as pelican spiders because of their unusual appearance, which resembles the shape of the water bird.
They are considered to be prone to fire because they live in leaf litter in low-lying vegetation, which is more likely to burn in bushfires.
Prior to the Kangaroo Island fires, the island’s assassin spider was known only from one location that was completely destroyed in the 2019-20 disaster.
Marsh said two specimens had since been discovered in another location 4 km away.
She said it highlighted a problem common to many invertebrates – that their habitat areas are sometimes so small that a single fire could be enough to affect the entire species.
Libby Rumpff, another co-author from the University of Melbourne, said the work also underscores conservation difficulties for so-called “data-deficient” species that have received little attention or funding.
“If you are found to be a lack of data, you are put in a box and just hoping someone will do something about it,” she said.
“Many invertebrates are little known because they are rare or have a limited range, and because vertebrates and the more charismatic groups are preferred.”
Marsh said she hoped the analysis would lead to a rethinking of conservation approaches to Australia’s invertebrates. This could include landscape-level conservation planning that protects entire habitat areas with high levels of endemic invertebrates, she said.
Such an approach could mean “we can protect species we know but also those we do not know”.
“Invertebrates have been overlooked and not appreciated by public opinion and decision-makers alike. That has to change, ”said Marsh. “We have to find a way to include invertebrates in conservation planning.”
Woinarski said if even the 60 species they recommend were listed as threatened, it would mean a profound change in the conservation status of Australian invertebrates.
He said there are other species Australia could lose without even realizing it.
“Invertebrates are the stuff of life. They are the linchpin of many of Australia’s food webs. If you clutter the invertebrate community, it inevitably has ramifications for things other than just these species. “