Genetic research has revealed the threatened Australian native bilby – with its ridiculously oversized ears and stretched snout – does not only look odd from the outside.
“Bilbies are weird and cool. The genome has been fascinating,” said Prof Carolyn Hogg, of the University of Sydney, who led research that sequenced the greater bilby’s genome for the first time.
“They’ve got the biggest genome of any marsupial – it’s got 3.66bn pieces to it,” Hogg, of the Australasian Wildlife Genomics Group, said.
The genetic sequence would help conservationists target their efforts to save the species that had already disappeared from about 80% of its range, Hogg said.
Quite why the bilby’s genome is so large could, in part, be down to how it has evolved its incredible sense of smell.
“Because they dig in the desert looking for grubs and seeds, they’re really important to the landscape and circulate the soil,” Hogg said.
Published on Monday in the journal Nature Ecology and Evolution, the research is the result of work to sequence the genome that started in 2018 but was held up because of the global pandemic.
The genetic blueprint of the bilby, a culturally important species for many Indigenous communities, includes information on how the elusive nocturnal omnivores grow and evolve.
Hogg said: “It helps us understand what gives bilbies their unique sense of smell and how they survive in the desert without drinking water.”
All 115 genes expressed in the human uterus to produce a placenta are also found in the bilby, Hogg said. “They’ve got so many fascinating genes.”
European invasion and the subsequent spread of feral cats, foxes and rabbits – the latter of which compete for food with bilbies – had seen bilby numbers plummet.
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The only other member of the bilby marsupial family – the lesser bilby – is extinct and is thought to have hung on in the landscape until the 1960s. The team also sequenced the lesser bilby using a scraping from the skull of a specimen collected in 1898.
Greater bilby numbers in the wild are not known, but about 6,000 live in sanctuaries that are either fenced for protection or located on islands.
The genome is already being used to help manage bilbies in zoos, fenced sanctuaries and islands.
Hogg said: “By selecting individuals for translocation and release we maximise their genetic diversity, thus improving the population’s ability to adapt to a changing world.”
A method to track and assess bilby populations using their scat had also been boosted by the genome sequencing, allowing for a more precise way to understand what was happening to wild populations.
Ranger Scott West, of the Kiwirrkurra Indigenous Protected Area in Western Australia, said: “We know a lot about bilbies – where they live, what they eat, and how to track them.
“It’s good to use iPads for mapping, and cameras to monitor them. The DNA work also helps check if bilbies are related, where they are from and how far they travelled.”
