The highest point on the cay is 3 meters (10 feet) above the regular high-tide mark. A rise of 10 centimeters (4 inches) in sea level at nearby locations between 1993 and 2010 has done away with whatever safety margin the rat had, shrinking its area by almost 40 percent. Extreme weather events in the region in recent years have probably put the entire island under water during storm surges.
Even if the animal inhabitants survived inundation, their food supply would not, with plants at the south end of the cay flattened, apparently in a recent storm.
“Significantly, this probably represents the first recorded mammalian extinction due to anthropogenic climate change,” the report notes.
Researchers left no stone unturned in the search for Melomys rubicola. Natallie Waller
Sadly, there appears to be no evidence that these rats left a sinking island for higher ground, although the report adds that M. rubicola may have arrived at the island from Papua New Guinea's Fly River Delta 53 kilometers (33 miles) away, and relatives may survive on islands there.
The discovery is bad news for other local species, with the report noting: “Bramble Cay is the most important rookery in Torres Strait for green turtles (Chelonia mydas) and a variety of seabirds.”
According to one estimate last year, one in six living species will soon follow in its tiny footsteps.
[H/T: The Guardian]