The Bramble Cay melomys was thriving when European explorers first discovered the rodent species in 1845. By 2002, only a few dozen remained.
By Madeleine Thomas
(Photo: Luke Leung)
It’s official: The Bramble Cay melomys, a rat-like, long-whiskered rodent, is the first known mammal to go extinct because of human-induced climate change. Researchers from the University of Queensland and the Queensland Government confirmed the news in a report released this week.
The culprit? Sea-level rise. Bramble Cay, the melonys’ only known habitat, is a small, low-elevation island sitting atop a coral reef in the Torres Strait — a stretch of water sandwiched between Queensland, Australia, and Papua New Guinea. The entire cay sits less than 10 feet above the ocean and measures just roughly 1,100-by-500 feet wide. Over the last decade, rising waters have likely destroyed much of the melomys’ habitat — or have swept them out to sea. Vegetation cover, crucial food, and shelter for the rodents has declined by as much as 97 percent over the last 10 years, the University of Queensland researchers found. And humans are to blame.
“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,” Luke Leung, a University of Queensland researcher and the study’s lead author, said in a statement. “Significantly, this probably represents the first recorded mammalian extinction due to anthropogenic climate change.”
Humans are to blame.
When the Bramble Cay melomys was first discovered by European explorers in 1845, the rodents numbered so high that seamen shot them with bows and arrows from aboard their ships just for fun. Yet, by 1978, melomys’ numbers had already dropped to just a few hundred. By 2002, as few as several dozen remained on all of Bramble Cay. The rodent is the only mammal endemic to Australia’s Great Barrier Reef.
In March 2014, scientists re-visited Bramble Cay to scour the island for a trace of the melomys — without any luck. They searched the site again the following August as a last attempt to locate and rehabilitate any remaining melomys. After some 900 small animal traps and 60 camera traps still couldn’t generate proof of the rodent’s existence, the researchers decided to throw in the towel. It appeared that the Bramble Cay melomys had gone extinct.
Researchers believe the melomys ultimately disappeared sometime between 2009 and 2011. This time frame was corroborated by local fishermen who have spent the last several decades visiting Bramble Cay to fish for mackerel, they noted in their report. One fisherman claimed the last time he caught a glimpse of the melomys on the island was in 2009, when he saw one or two of the rodents scurry out from underneath of dug-out canoe.
Although the Bramble Cay melomys isn’t known to live on any other islands in the Torres Strait or in the Great Barrier Reef, researchers have yet to confirm whether the species is extinct on a full-fledged, global level. It is believed that the rodent, or at least a few of its close relatives, could exist on the Fly River delta of Papua New Guinea, an area where the melomys may have originated. There may be hope for the little creature yet.