Scientists from Curtin University, the Western Australian Museum and Murdoch University have identified three new species of mulgaras — small carnivorous marsupials related to the Tasmanian devil and quoll — and the researchers fear these new species may no longer exist in the wild.
The crest-tailed mulgara (Dasycercus cristicauda). Image credit: Bobby Tamayo / CC BY-SA 4.0 Deed.
Mulgaras (genus Dasycercus) are small carnivorous marsupials found throughout Australia’s arid and semi-arid bioregions.
These creatures prey on a large variety of small fauna, including small mammals, reptiles, and invertebrates.
Throughout their distribution, mulgaras aid in ecosystem management, including via bioturbation (soil turnover) during burrowing and foraging for insect prey, with individuals using multiple burrows over their home range.
Australia lacks many large carnivorous species, owing to the extinction of megafauna at the end of the Pleistocene epoch.
As such, the natural ecological roles of carnivores in many regions are filled by smaller species such as mulgaras.
Since European arrival, mulgaras have experienced declines in their geographic distribution, most likely as a result of domestic cat predation.
Currently there are two recognized species of mulgaras: the crest-tailed mulgara (Dasycercus cristicauda) and the brush-tailed mulgara (Dasycercus blythi).
Dasycercus blythi is known to occur over much of the arid zone, including sympatrically in some areas with Dasycercus cristicauda.
Specimens collected on the Canning Stock Route indicate that Dasycercus cristicauda occurs in sand dune environments, while Dasycercus blythi occupies Spinifex grasslands within the same geographic range.
“Our research had identified six species of mulgaras, as opposed to the previously accepted two and it also concluded that a third previously named mulgara, Dasycercus hillieri, was indeed a valid species,” said Curtin University Ph.D. student Jake Newman-Martin.
“However, Dasycercus hillieri and three new species (Dasycercus woolleyae, Dasycercus archeri and Dasycercus marlowi) appeared to be already extinct.”
In the study, Newman-Martin and colleagues analyzed preserved specimens of mulgaras from museums across the country, including bones found in caves which had previously not been identifiable.
“Known as ‘ecosystem engineers,’ mulgaras are immensely important to the regions they inhabit as they help control the population of insects and small rodents and assist turning over the desert soils by burrowing,” Newman-Martin said.
“By taking precise measurements of the skulls and teeth of preserved mulgara specimens, we were able to differentiate the species, the exact number of which had previously been the source of some debate.”
“Using the skulls and teeth of mulgaras had previously not been achievable because no study had documented and measured the bones in detail.”
“Our study shows that mulgaras are actually far more diverse than previously thought.”
“While the discovery of more species of mulgaras may sound like good news, the fact they were likely already extinct was disconcerting,” said Dr. Kenny Travouillon, curator of mammalogy at the Western Australian Museum.
“While Australia is renowned for its diverse and unique marsupials, it also has the highest mammalian extinction rate in the world, with many species suffering from the impacts of environmental degradation and introduced predators such as foxes and cats.”
“The most at-risk species are often overlooked small marsupials, which have suffered a great drop in their abundance and distribution since European colonization.”
“Mulgaras may even represent the first recorded Australian extinction within the broader family of related animals (Dasyuridae) and are sadly disappearing with even less recognition than their now infamous ‘cousins’ the Tasmanian tiger.”
“It is likely that many more undescribed species have already become extinct before they could be known to science, highlighting the need to better understand Australian wildlife and the growing threats to our ecosystems.”
The discovery is described in a paper in the Alcheringa, an Australasian Journal of Palaeontology.
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Jake Newman-Martin et al. Taxonomic review of the genus Dasycercus (Dasyuromorphia: Dasyuridae) using modern and subfossil material; and the description of three new species. Alcheringa, published online October 22, 2023; doi: 10.1080/03115518.2023.2262083
