The Bramble Cay melomys, also called the mosaic-tailed rat, has been completely wiped-out from its only known location - a small coral cay off the north coast of Queensland, Australia. It had the most isolated and restricted range of any Australian mammal, and was considered the only mammal species endemic to the Great Barrier Reef. This is also the first recorded extinction of a mammal anywhere in the world thought to be primarily due to human-caused climate change. Researchers concluded the “root cause” of the extinction was sea-level rise. As a result of rising seas, the island was inundated on multiple occasions killing the animals and also destroying their habitat.
For low-lying islands like Bramble Cay, the destructive effects of extreme water levels resulting from severe meteorological events are compounded by the impacts from anthropogenic climate change-driven sea-level rise. It was estimated the area of the cay above high tide has decreased from 4ha in 1998 to 2.5ha in 2014. The melomys lost 97% of their habitat in just 10 years.
Globally, averaged sea level has risen by almost 20cm between 1901 and 2010, a rate unparalleled in any period during the last 6,000 years. But around the Torres Strait, sea level appears to have risen at almost twice the global average rate between 1993 and 2014.
When its existence was first recorded by Europeans in 1845, the Bramble Cays melanomys was seen in high density on the tiny island in the eastern Torres Strait, with sailors reporting they shot the “large rats” with bows and arrows. In 1978, it was estimated there were several hundred on the small island. But the melomys were last seen in 2009, and after an extensive search for the animal in 2014, a report has recommended its status be changed from “endangered” to “extinct”. Researchers concluded the “root cause” of the extinction was sea-level rise. As a result of rising seas, the island was inundated on multiple occasions, they said, killing the animals and also destroying their habitat.