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CLIMATE change is believed to have caused the extinction of a rodent found on a small island in the Great Barrier Reef.

According to Queensland researchers, the species is the first mammal declared extinct due to the worrying global phenomenon.

Extensive searches for the Bramble Cay melomys, a small rat-like animal, have failed to find a single specimen from its only known habitat on a small coral cay, just 340m long and 150m wide in the northern end of the Great Barrier Reef and the edge of the Torres Strait Islands.

In a newly published report, scientists at the University of Queensland detailed how a comprehensive survey in 2014 failed to find any trace of the rodent.

Researchers said the key factor behind the extinction was “almost certainly” ocean inundation of the low-lying cay, likely on several occasions, over the last decade which resulted in dramatic habitat loss.

“Because a limited survey in March 2014 failed to detect the species, Bramble Cay was revisited from August to September 2014, with the explicit aims of establishing whether the Bramble Cay melomys still persisted on the island and to enact emergency measures to conserve any remaining individuals,” researcher Luke Leung said.

Dr Leung is from the University of Queensland’s School of Agriculture and Food Sciences and said the team went to great lengths in hopes of recovering signs of the species.

“A thorough survey effort involving 900 small animal trap-nights, 60 camera trap-nights and two hours of active daytime searches produced no records of the species, confirming that the only known population of this rodent is now extinct,” he said.

Bramble Cay is the only known location of the rodent and the island sits just three metres above sea level.

Available data on sea-level rise and weather events in the Torres Strait region “point to human-induced climate change being the root cause of the loss of the Bramble Cay melomys”, added the study.

Anthony D. Barnosky, a professor at the University of California, Berkeley who is a leading expert on climate change’s effects on the natural world said the claim seems “right on target to me.”

“I think this is significant because it illustrates how the human-caused extinction process works in real time,” he told the New York Times.

The Bramble Cay melomy, considered the Great Barrier Reef’s only endemic (found nowhere else) mammal species, was first discovered on the cay in 1845 by Europeans who shot them for sport. They considered them large rats at the time.

But the last known sighting, by a professional fisherman, was in 2009.

The 2015 IUCN Red List of Threatened Species implicated climate change in the extinction of another mammal, the Little Swan Island hutia (Geocapromys thoracatus), a rodent previously found on a coral atoll in Honduras. But it found the main driver of its demise was an introduced cat, the report said.

Dr Leung said in the case of the Bramble Cay melomy, all signs pointed to the culpability of climate change.

“Available information about sea-level rise and the increased frequency and intensity of weather events producing extreme high water levels and damaging storm surges in the Torres Strait region over this period point to human-induced climate change being the root cause of the loss of the Bramble Cay melomys,” he said.

The study added that the main hope for the species was that another population existed in neighbouring Papua New Guinea.

Environment group WWF-Australia said the fate of the species was a sad reminder of the nation’s extinction crisis.

“Australia officially has the worst rate of mammal extinction in the world,” WWF spokesman Darren Grover said.

Unless governments commit significant funding towards protecting Australia’s threatened species, “we can expect to see more native critters go extinct on our watch”, he added.