No one has seen a Bramble Cay melomys since 2009. And now it seems that no one will ever see it again. In a detailed report issued this week, Australia's Queensland government has announced the extinction of the rare rodent. The cause? Humans.

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Goodbye, Bramble Cay melomys. Image: The State of Queensland, Environmental Protection Agency

Technically known as Melomys rubicola, the diminutive creature was known to inhabit just a tiny spot called Bramble Cay off the tip of Queensland. That’s how report author Ian Gynther and his colleagues can be so sure that the mammal isn’t there anymore. A thorough search of the speck of land, involving 900 small-mammal traps and 60 camera traps, carried out in August and September of 2014 failed to produce any trace of the species.

The immediate cause of the rodent’s extinction was habitat loss. “The key factor responsible for the extirpation of this population was almost certainly ocean inundation of the low-lying cay”, the report states.

Rising waters squeezed the habitat of the Bramble Cay melomys, and possibly even drowned the helpless mammals. But when it comes to the ultimate cause, we can blame the climatic changes happening on a global scale. It's the raising sea levels and storm surges linked to human-caused climate change that ultimately devastated the rodent’s habitat, Gynther and colleagues state.

This is the first time that researchers have been able to directly tie the demise of a species to human-caused climate change. “There is almost no doubt the Bramble Cay melomys is extinct, and there is no doubt that this is caused by habitat loss due to sea level rise,” University of Queensland conservation expert James Watson told New Scientist.

Naturalists have been expecting such an extinction for some time – and this just happens to be one we've noticed. There may be other species driven over the edge by climate change that were not discovered or extensively studied before they disappeared.

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Bramble Cay lies among a group of islands located in the Torres Strait, the waterway separating Australia's Cape York Peninsula and the island of New Guinea.

But while conservation experts are certain that the Bramble Cay melomys has vanished from the island it got its name from, there is still a small sliver of hope – and it might exist on the nearby island of New Guinea. 

Gynther and his team believe there's a slim chance a population of Melomys rubicola (or a closely related species) still survives in the Fly River Delta of Papua New Guinea. That’s because palm trees, mangrove branches and other debris sometimes wash up on Bramble Cay from Papua New Guinea. Along with anecdotes of rodents inhabiting the Fly River Delta, this might mean that the Bramble Cay melomys first evolved on Papua New Guinea before some seafaring rodents accidentally caught a ride on floating vegetation to the tiny Queensland island.

So far, there have been no confirmed sightings on Papua New Guinea, but if any furry survivors are still holding out there, it's possible the species may endure despite being wiped out on Bramble Cay. With luck, future searches might bring the Bramble Cay melomys back from the dead.