A tiny Australian rodent considered as the only endemic mammal species in the Great Barrier Reef may be the first documented victim of man-made climate change, a new report revealed.
During extensive searches, scientists failed to find even a single individual of the Bramble Cay melomys (Melomys rubicola) in its only known habitat, an island off the eastern Torres Strait.
Also known as the mosaic-tailed rat, the Bramble Cay melomys were last seen by a fisherman in 2009. Experts attempted to trap the rodent in 2014 but to no avail. This led them to believe that the animals have been wiped out.
Shrinking Island
Researchers from the 2014 study laid 150 traps on Bramble Cay for six nights and measured the island and its vegetation.
Bramble Cay is a tiny coral cay that is just 10 feet (3 meters) above sea level. Europeans first saw the rodents on this island in 1845, and by 1978, the animal's population grew to several hundreds.
However, since 1998, scientists say part of Bramble Cay has disappeared. From 4 hectares (9.8 acres), it shrunk to 2.5 hectares (6.2 acres).
And as the island's vegetation shrank, the rodents lost 97 percent of their home.
The main factor behind the animals' extinction was sea-level rise over the last 10 years, researchers concluded in their report [PDF]. As a result, the island was inundated multiple times, destroying the habitat and killing the rodents.
Is There Still Hope?
Across the globe, sea level has increased by almost 20 centimeters (8 inches) since the start of the 20th century, which scientists say is unparalleled in the last 6,000 years.
Around the Torres Strait, the sea level rise was double the global average rate between 1993 and 2014, researchers said.
With that, authors warn that the Bramble Cay melomys is only the first of many species threatened to go extinct due to a warming climate.
"We knew something had to be first," says senior scientist Lee Hannah from Conservation International. "But this is still stunning news."
The Queensland government suggests that no recovery actions be taken as the species is now gone.
"No recovery actions for this population can be implemented," the government wrote on its website.
Still, Ian Gynther from Queensland's Department of Environment and Heritage Protection and his colleagues mentioned in their study that although the species is extinct in Australia, there still may be hope: another population is allegedly located in Papua New Guinea.
"At this stage, it may be premature to declare the Bramble Cay melomys extinct on a global scale," the new study added.
