The first mammal driven extinct by climate change

Environment · Rudi Bressa · 2016-06-16

The Bramble Cay melomys was the only species endemic to the Great Barrier Reef. The rodent is extinct due to rising sea levels.

It is the first mammal to be declared extinct due to climate change. Specifically, it is Melomys rubicola, a small rodent endemic (that is, exclusive) to Australia's Great Barrier Reef.

mammifero — A specimen of the grassland melomys, closely related to Melomys rubicola. Image courtesy of Diete Rebecca and Luke Leung.

The announcement comes from the latest report published by the University of Queensland, which presents the results of research conducted in 2014 that led to the Bramble Cay melomys being considered extinct in the wild.

The small rodent lived on a tiny coral island 340 metres long and 150 metres wide, in the Torres Strait, between the Australian state of Queensland and Papua New Guinea. The last recorded sightings are from 2009, by a fisherman who had been visiting the island annually for ten years. "Since a first survey in March 2014 had produced no sightings," explains University of Queensland scientist Luke Leung in a press release, "Bramble Cay was visited from August to September 2014, with the aim of establishing whether the Bramble Cay melomys persisted on the island and of implementing emergency measures to conserve any remaining individuals."

A specimen of the Bramble Cay melomys (Melomys rubicola), November 2002 (Ian Bell, EHP)

Bramble Cay in 2011 - photo by Natalie Waller

Bramble Cay islet, in 2011. Photo via Natalie Waller

Elliott traps were used to survey the melomys during three survey periods - photo by Natalie Waller

The traps used to capture the melomys during the research period. Photo via Natalie Waller.

Natalie Waller checking elliott traps in 2011 - photo by karen evans

Researcher Natalie Waller checks the traps in 2011. Photo via Karen Evans.

The first mammal driven extinct by rising sea levels

"The survey, conducted using 900 traps for small animals, 60 night-vision cameras and two hours of daytime searches, produced no sightings of the species whatsoever, confirming that the only known population of this rodent is now extinct," states University of Queensland scientist Luke Leung.

According to the study, the key factor appears to be precisely the rise in sea levels and the increase in extreme weather events, which would have flooded the burrows over and over again throughout the years, killing several individuals and destroying their habitat. "This probably represents the first case of a mammal being driven to extinction by human-induced climate change," confirms Leung.

Aumento del livello dei mari. Immagine via Epa. — Rising sea levels. Image via Noaa.

According to data collected by the Epa (the United States Environmental Protection Agency) and published last June, since 1993 sea levels have been rising by between 0.28 and 0.35 centimetres per year, marking a rate twice as fast as the long-term trend recorded (from approximately 1880). Between the early 1900s and 2010, the figure stands at an average of 20 centimetres.