Mouse believed to be extinct for 150 years is found on remote islands

A species of mouse believed to have been extinct for more than 150 years has been discovered alive in a cluster of remote islands off Western Australia.

Gould’s mouse was once common across a vast stretch of mainland Australia but declined rapidly after European colonisation started in 1788.

It had disappeared by the 1850s, possibly due to hunting by feral cats or competing species of rat and mouse introduced by settlers.

Scientists comparing DNA samples from dozens of living and extinct native rodents found that the Shark Bay mouse, known to exist on small islands off the coast of Western Australia, is identical to Gould’s mouse.

The discovery allowed them to ‘taxonomically resurrect’ the rodent, which was written off as one of many species wiped out by the influx of Europeans.

The researchers said the find ‘brings good news in the face of the disproportionally high rate of native rodent extinction’.

Emily Roycroft, an evolutionary biologist from the Australian National University who authored the study, said: ‘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.’

Native mice account for more than two-fifths of all Australian mammals to have become extinct since 1788, according to the study.

The researchers were able to sequence genes from 50 species dating back 184 years using specimens from museum collections.

The wide range of species enabled them to reconstruct in more detail how and when populations declined.

Whereas some native Australian animals, such as the Tasmanian tiger, had become extinct on the mainland before British settlement, the study reveals rodents were flourishing.

It said the sudden disappearance of several native rodents was clearly linked with man-made pressures, such as ‘predation by feral cats and foxes, competition with introduced rodents, anthropogenic environmental disturbance, habitat destruction by introduced herbivores, inappropriate fire management, the introduction of novel diseases, and climate change’.

Ms Roycroft added: ‘The loss of so many species of native rodents means a loss of integral parts of Australian ecosystems.

‘Native rodents feed on many plants, fungi, and invertebrates, and in turn are a source of prey for many native carnivores. In the absence of native rodents, entire Australian ecosystems are potentially at risk of collapse.’