Guest essay by Eric Worrall
Claims are flying that Global Warming has claimed its first mammal, a kind of rat which used to live on just one small island in the Cyclone prone Torres Strait, off the Northern coast of Australia.
Human-caused climate change appears to have driven the Great Barrier Reef’s only endemic mammal species into the history books, with the Bramble Cay melomys, a small rodent that lives on a tiny island in the eastern Torres Strait, being completely wiped-out from its only known location.
It is also the first recorded extinction of a mammal anywhere in the world thought to be primarily due to human-caused climate change.
An expert says this extinction is likely just the tip of the iceberg, with climate change exerting increasing pressures on species everywhere.
The rodent, also called the mosaic-tailed rat, was only known to live on Bramble Cay a small coral cay, just 340m long and 150m wide off the north coast of Queensland, Australia, which sits at most 3m above sea level.
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.
When its existence was first recorded by Europeans in 1845, it was seen in high density on the island, 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”.
Calling the dead rats a victim of “climate” seems a bit of a stretch. A small population species which precariously clings to existence on a tiny spit of low lying land in the middle of Australia’s Cyclone Alley was never destined to survive for long.
From the Australian Government Website;
There are three threats to the species. Firstly, there is only the single known population of the species and searches on other cays and in adjacent areas of New Guinea have failed to discover other populations. Secondly, the cay is prone to inundation from storm surge and other disturbances. Further compounding risk to the species is that the species appears to be inbred. Therefore, resilience of the species to catastrophic events such as cyclones, introductions of weeds or introduced predators, or the arrival of a novel disease, is very low (Curtis et al. 2012 cited in DEHP 2013e).
The most recent survey for the species in 2012 resulted in no animals being recorded. The most recent verified record of the species is from trapping in 2004. It is possible that a catastrophic inundation of the island has already occurred (DEHP 2013e).