It's official in the eyes of Australia: A small brown rat is the first known mammal to be eradicated as a result of human-induced climate change. Bramble Cay melomys were declared extinct by Queensland's government in 2016 after a series of research trips failed to locate the animal in its only known home: a five-hectare sand island in the Torres Strait, which separates Australia's northernmost tip and the southern coast of Papua New Guinea, per the BBC. The federal government's decision to follow suit—revealed Monday—"was not a decision to take lightly," an environment official says, per the Age, noting "there's always a delay while the evidence is gathered to be absolutely certain." There is a chance that a similar or identical species resides in a nearby region of Papua New Guinea, but little research has been done there.
Queensland's government noted the main factor in the extinction "was almost certainly ocean inundation of the low-lying cay ... causing dramatic habitat loss and perhaps also direct mortality of individuals," per Fox News. "Rising sea levels and an increased incidence of extreme weather events ... point to human-induced climate change being the root cause," added the 2016 report. It came eight years after a recovery plan criticized as downplaying risks to the animal in a country with one of the highest overall extinction rates. While the federal government touts a $425 million investment in threatened species programs, others are in mourning. "The Bramble Cay melomys was a little brown rat," says the Wilderness Society's Tim Beshara. "But it was our little brown rat and it was our responsibility to make sure it persisted. And we failed." (Read more extinction stories.)