15/06/2016 7:59 AM AEST | Updated 15/07/2016 12:54 PM AEST

The Mosaic-Tailed Rat From The Great Barrier Reef Is Now Extinct Due To Climate Change

The rat's home was the size of three MCGs. Now it's gone.

David Carter / Department of Environment and Heritage Protection
This is the face of climate change -- a now-extinct rat.

The first mammal wiped out from climate change is an Australian rat that lived on a tiny island on the Great Barrier Reef.

Bramble Cay is so small, it's not technically an island, but a cay, at 340m by 150m which is a 20-minute walk from end to end or about the size of three Melbourne Cricket Grounds.

Here it is as seen from Google Maps.

Google Maps

Never the less, this cay was home to a population of Bramble Cay melomys, also known as the mosaic tailed rat but in 2014, a search for the once-endemic rodent revealed nothing.

In a report released in June 2016 by the Queensland Government and the University of Queensland, researchers found the last anecdotal sighting of the rat was from fishermen in the area in 2009.

The report found climate change-exacerbated sea level rise seriously impacted the island, which was only 3m above sea level at its highest point, and the presumption is that the cay was temporarily submerged, killing the rats.

"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."

WWF-Australia spokesperson Darren Grover said threatened species like these rats needed better protection.

"Australia's species extinction crisis is not something that occurred hundreds of years ago, it's happening right now -- Australia officially has the worst rate of mammal extinction in the world," Grover said.

"Unless State Governments and the next Australian Government commit significant amounts of funding towards protecting Australia's threatened species, we can expect to see more native critters go extinct on our watch.

"A dramatic change in funding for the country's Threatened Species Strategy is needed as part of the upcoming election if we are to safeguard our unique wildlife into the future."

The Short-Nosed Sea Snake is critically endangered and had only ever been found in a 10 square-kilometre zone of Ashmore Reef and Hibernia Reefs off the coast of northern Western Australia. They were thought to be extinct until researchers found a breeding pair in 2015.

The Mountain Pygmy Possum is believed to only live in Kosciuszko National Park in NSW as well as three Victorian locations: Bogong High Plains, at Mt Bogong and between Mt Loch and Mt Higginbotham and in the Mt Buller ski resort area.

The critically endangered Mt Lofty spotted quail-thrush only lives in the eponymous Mount Lofty Ranges in South Australia.