The first recorded mammal extinction due to human-induced climate change has just been confirmed. Scientists from the University of Queensland in Australia have verified that the Bramble Cay melomys, Melomys rubicola, has most likely gone extinct. The Bramble Cay melomys, also known as the Bramble Cay mosaic-tailed rat, was a small, brown rodent that lived in fields. The Bramble Cay melomys had a limited range in Queensland and dug burrows into the ground. They lived in areas below sea level, something that contributed to their extinction.
The authors of the paper, intended for the Department of Environment and Heritage Protection, had first done a survey in March 2014 but didn’t find any of the rodents. The last possible sighting of a Bramble Cay melomys had been back in late 2009 so these surveys were an effort to protect any remaining melomys. When the first survey didn’t detect any of the rodents, a much larger, more intensive survey was conducted in August and September of that same year. The researchers set 900 live traps each night, utilized 60 night vision cameras, and conducted extensive daytime surveys on foot. They didn’t find any signs of the Bramble Cay melomys and have therefore recommended that the species be marked as extinct.
The researchers believe that recent human-induced climate change is to blame. Rapidly rising sea levels in the areas the melomys lived in caused extreme habitat loss and frequent severe storms made things even worse for the rodents. Many were likely killed directly from the rising water and storms while the survivors had nowhere to go. This is not the first species to go extinct due to recent climate change (the golden toad, for example, was the first documented extinction attributed to global warming). The Bramble Cay melomys, however, represents the first recorded mammal extinction due to human-caused climate change.
The authors do want to do another survey, this time in the Fly River region of Papua New Guinea. Previously, there had been research supporting a hypothesis that this area may be where the melomys originated. There’s a small chance that Bramble Cay melomys or a closely-related species could still live there. Therefore, while the authors recommend the species be marked as “extinct”, they also point out the need for more surveys. The researchers also recommend that we take action to protect other species in the Bramble Cay area since the rising sea levels could affect the turtle and seabird populations.
Gynther, I., Waller, N. & Leung, L.K.-P. Confirmation of the extinction of the Bramble Cay melomys Melomys rubicola on Bramble Cay, Torres Strait: results and conclusions from a comprehensive survey in August–September 2014. Department of Environment and Heritage Protection (2016).