Extinction obituary: how the Bramble Cay melomys became the first mammal lost to the climate crisis | climate crisis

No one knows how the Bramble Cay melomyses – rodents with large, liquid eyes and reddish-brown fur, small enough to fit in the palms of your hands – ended up on Bramble Cay.

The cay is speck of land about 50km (31 miles) off the coast of Papua New Guinea, at the northern end of the Great Barrier Reef. Were the melomyses washed there on driftwood in a storm? Did they arrive thousands of years ago on a land bridge that no longer exists?

Those questions may well go unanswered for ever: in 2015, the Bramble Cay melomys became the first mammal to go extinct directly because of human-caused climate breakdown. Their story is part of Extinction Obituaries, a Guardian series that documents the lives of species that have disappeared in living memory.

Bramble Cay is only a little larger than an average US shopping mall. The highest point is about 10 feet above sea level. But it was a lifeboat for the melomyses, who were some of the most isolated mammals in the world.

Life on Bramble Cay for the melomyses appeared simple. They lived in the shelter of the leafy shrubbery they munched on, scampering in the sand of their secluded home – their routine interrupted only by the excitement of visiting humans and birds, or occasional storms.

Their decline was swift and alarming. In reports from 1978, scientists documented several hundred individual melomyses. A 1998 survey report by the Australian government counted just under 100.

The tiny cay and its essentially trapped inhabitants were susceptible to even small changes in the surrounding ocean. Climate change and rising sea levels led to salt-water intrusions throughout the island, choking much of the flora – in the decade between 2004 and 2014, the volume of leafy plants on Bramble Cay shrank by 97%. Storm surges also winnowed down the population, sweeping animals out to sea.

When biologists returned in 2002 and 2004, only about a dozen melomyses could be found. Natalie Waller, a conservation biologist with the Carpentaria Land Council Aboriginal Corporation, was one of the scientists who voyaged to Bramble Cay in 2011 and again in 2014 with the express purpose of trapping, or at least documenting, whatever melomyses were left.

“We didn’t catch any,” she remembers sadly. The team scoured the island, placing rodent traps around the sandy cay and installing cameras for surveillance. “We were planning on setting up a captive insurance population,” Waller says – but there was simply no trace of a single melomys. Even searches for scat and nesting grounds yielded nothing.

The International Union for Conservation of Nature declared the Bramble Cay melomys as extinct in 2015. At some point biologists collected tissue samples of the melomys in order to record its genetic information, but they too now appear to have been lost.

Bramble Cay has been a gathering place for generations of Torres Strait Islanders, says Jimmy John Thaiday, an Indigenous artist. “Our ancestors would go there – our grandfathers, our fathers’ grandfathers.” Torres Strait Islanders have designated land and sea rangers who visit various cays in the area every few months to monitor and manage wildlife. They tend to the plants, tag turtles and document populations. They are trying to maintain Bramble Cay as it is, or at least, slow the progression of its decline.

To help remember and mourn the melomys – called the maizub kaur mukeis in the Aboriginal Meriam Mir language – Thaiday and other artists sculpted a family of melomyses out of ghost nets, largely abandoned debris from the fishing industry, as a comment on the vulnerability of island ecosystems. The art project is an elegy to the mukeisa different way to preserve the species – though a poor substitute for a living creature.