A decade-long research project led by the Western Australian Museum has uncovered two previously unrecognised species of short-nosed (brown) bandicoots, significantly reshaping scientific understanding of one of Australia’s most familiar marsupials.
The project began in 2016 when Western Australian Museum Terrestrial Zoology Curator Dr Kenny Travouillon received a Churchill Fellowship to examine more than a century's worth of Australian bandicoot specimens held in museums across Europe and the United States. The findings from that work led to a larger Australian Biological Resources Study-funded project involving collaborators from the South Australian Museum to revise all Australian bandicoot species.
Researchers examined and measured museum specimens from Australia and overseas and conducted DNA analyses to reassess species and subspecies boundaries within the genus Isoodon (short-nosed bandicoots).
The study identified two additional species, the Little Brown Bandicoot (Isoodon microtis), a species from South Australia that became extinct around 100 years ago, and the New Guinea Brown Bandicoot (Isoodon moresbyensis), which was previously considered a subspecies of the Northern Brown Bandicoot.
The research also revealed a major range extension for the Quenda (Isoodon fusciventer), Western Australia's native brown bandicoot, showing that it historically occurred not only in Western Australia but also around Adelaide, the Nuyts Archipelago and Kangaroo Island in South Australia. As a result, South Australia is now recognised as having supported three Isoodon species rather than just one.
In addition, the team described seven new subspecies across the Golden Bandicoot (Isoodon auratus), Quenda and Northern Brown Bandicoot, highlighting the remarkable diversity that once existed across Australia.
“One of the most surprising discoveries was identifying a species that had already gone extinct before anyone realised it was distinct.
“While it is sad that the Little Brown Bandicoot disappeared more than a century ago, recognising its existence helps tell its story and strengthens our efforts to protect the bandicoot species that remain,” Dr Travouillon said.
The findings have important conservation implications. The newly recognised distributions and species boundaries may require reassessment of conservation status across several bandicoot groups. While the wider historical range of the Quenda suggests it may be less vulnerable than previously thought, South Australian populations remain under pressure. Conversely, the already endangered Southern Brown Bandicoot may be at greater risk than previously recognised.
The completion of the Isoodon revision marks the first stage of a broader effort to revise Australia’s bandicoots. The team will now focus on the genus Perameles (long-nosed bandicoots), a group that has already suffered multiple extinctions since European settlement.
This research was supported by the Winston Churchill Memorial Trust, the Australian Biological Resources Study, and Bioplatforms Australia through the Commonwealth Government National Collaborative Research Infrastructure Strategy, with contributions from researchers and institutions across Australia and assistance from the Wunambal Gaambera Aboriginal Corporation’s Uunguu Rangers in the Kimberley.
The research paper, Genetic and morphological reassessment of the genus Isoodon and description of new species and subspecies, has been published in Australian Journal of Taxonomy and is available to read here.
