This supposedly extinct mouse could hide for decades by switching identity

During its heyday, the Gold rat roamed mainly in New South Wales in Australia. The rodent was slightly smaller than the black rat and lived in groups of four to eight rats. It had brown fur, a white belly, and medium sized ears. In adulthood he weighed about half a kilogram. In the past tense, because it was believed that rodents were extinct.

It has been from 1857 since a live specimen was seen (and captured). But it wasn’t until 1990 that the International Union for Conservation of Nature and Natural Resources (IUCN) officially declared the mouse extinct. Thirty years later, the Golds rat is still alive. The mouse has just exchanged its native habitat (in eastern Australia) for a few islands off the coast of Western Australia and changed its name.

Identification

How does mouse golds suddenly happen? The “extinct” Australian rat has pretended to be a different species of rat for 150 years. “Using genomics from historical museum samples, we showed that the Golds rat is exactly the same as the Alice Springs rat (Bay Mouse Co, Editor),” said lead researcher Emily Roycroft. “It is a typical case of identity change. So Golds rat has been hiding in plain sight all this time, just under a different name.”

So it was a coincidence that Roycroft’s team ran into a mouse. The research design was actually to map the decline of native species since the arrival of the Europeans. By comparing the DNA samples of eight extinct Australian rodents with the DNA of 42 living relatives, the researchers noticed that there was no difference between the Alice Springs mouse and the Golds mouse.

The arrival of the Europeans

According to the researchers, the fact that the habitat of the “new” Golds rat has changed significantly compared to 150 years ago shows that the population has shrunk dramatically. This may have something to do with the arrival of the Europeans. The environment and threats have changed so dramatically after the arrival of the Europeans that these species have not been given a chance to adapt. This has been caused by a number of different factors, including the introduction of wild cats, foxes, and other invasive species, the shift to farmland, inadequate fire control, and the spread of new diseases.”

Roycroft stresses that this is still a major problem for Australia’s native species: “We are at risk of losing a lot of Australia’s biodiversity. Currently, not enough is being done to prevent this.”