A mouse that was thought to have been extinct for 150 years in Australia has been found alive, thanks to a new genetic study. The experts report that Gould’s mouse did, in fact, disappear from the mainland yet persists on islands in Western Australia.
In an effort to investigate the decline of native species since the arrival of Europeans in Australia, the researchers analyzed DNA samples from eight extinct Australian rodents and from more than 40 of their living relatives.
The study revealed that the Gould’s mouse was indistinguishable from the Shark Bay mouse, which is still found on several small islands off the coast of Western Australia.
Study lead author Dr. Emily Roycroft is a postdoctoral researcher in the College of Science at Australian National University (ANU). She described the discovery as both exciting and sobering.
“The resurrection of this species brings good news in the face of the disproportionally high rate of native rodent extinction, making up 41 percent of Australian mammal extinction since European colonization in 1788,” said Dr. Roycroft.
“It is exciting that Gould’s mouse is still around, but its disappearance from the mainland highlights how quickly this species went from being distributed across most of Australia, to only surviving on offshore islands in Western Australia.It’s a huge population collapse.”
The seven other extinct native species that were sampled were found to have all had high genetic diversity immediately before they were wiped out. These levels of genetic diversity indicate that the rodents had large, widespread populations prior to the arrival of Europeans, said the researchers.
“This shows genetic diversity does not provide guaranteed insurance against extinction,” said Dr.Roycroft. “The extinction of these species happened very quickly.”
“They were likely common, with large populations prior to the arrival of Europeans. But the introduction of feral cats, foxes, and other invasive species, agricultural land clearing and new diseases have absolutely decimated native species.”
“We still have a lot of biodiversity to lose here in Australia and we’re not doing enough to protect it.”
The study is published in the journal Proceedings of the National Academy of Sciences.
By Chrissy Sexton, Earth.com Staff Writer