Extinct Australian rodent offers lessons in lost opportunity

The extinction of a tiny brown rodent in Australia, blamed on climate change, has been described as a "national tragedy" by environmentalists and scientists who said it could have been avoided.

The rodent, known as the Bramble Cay melomys, had inhabited the small, barren island of Bramble Cay in the northeast of the Torres Strait near Papua New Guinea.

Professor John Woinarski of Charles Darwin University, a specialist on the tiny mammal, said the extinction could have been prevented with some early intervention by the government. The mammal was doomed largely due to climate change as the island it lived on was virtually at sea level and open to wild fluctuations in weather and the rise in sea level, he said.

An effort to save it could have been made years ago as sea levels began to rise due to climate change, he said. The fact that the island was low lying means it was slowly being eroded with high tides and storm surges, giving the small creature little chance of survival.

The announcement that the Bramble Cay melomys was extinct was made in an official press release on Feb 18. Since the European settlement in Australia more than 200 years ago, 34 species of mammals have become extinct.

The fact, due mainly to imported cats and foxes in the past, is an appalling statistic considering that only one animal in North America has become extinct in the same period, according to Woinarski. Another 450 species of Australian animals are now on the endangered list along with 1,400 plant species, and the list is growing.

Perhaps more alarming is the number of disappearing insects. According to a study published in the latest issue of the conservation biology journal Biological Conservation, more than 40 percent of insect species (globally) may become extinct "over the next few decades".

"Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades," the study warned. It was conducted jointly by researchers from universities in Australia and the Chinese Academy of Agricultural Sciences in Beijing.

Why should we be worried about the loss of insects? Insects are by far the most varied and abundant creatures, outweighing humanity by 17 times. They are "essential" for the functioning of all ecosystems, researchers involved in the study said, as food for other creatures, pollinators and recyclers of nutrients.

"There is reason to worry," said lead author Francisco Sanchez-Bayo, a researcher at the University of Sydney. "If we don't stop it, entire ecosystems will collapse due to starvation."

The study, the first global survey of research on insect populations around the world, singles out a few groups of insects that are particularly threatened: moths and butterflies; pollinators like bees; and dung beetles, along with other insects that help decompose feces and detritus.

The main drivers have been habitat loss and conversion to intensive agriculture and urbanization; pollution, mainly that by synthetic pesticides and fertilizers; biological factors, including pathogens and introduced species; and climate change.

"If insect species losses cannot be halted, this will have catastrophic consequences for both the planet's ecosystems and for the survival of mankind," according to the study.

Dr Tanya Latty, an entomologist with the School of Life and Environmental Sciences at the University of Sydney, said entomologists have long suspected a decline in insect numbers.

"It's the one thing you tend to notice in your career, but the problem is we do not have that much data which cover insect numbers over a long period of time and in one place. And that is down to funding," Latty said.

"You can get funding for cuddly animals but who wants to sit down and count cockroaches for years in one place?

"There have been some studies done which have shown major declines in certain areas but nothing definitive and on a global scale," Latty said.

Some species will die out but others will replace them, she said. "But I don't think you can start talking about ecological collapse. There is a lot of space between everything being fine and collapse," she said. "The environment is complex."

Professor Philip Weinstein, professorial research fellow with the School of Biological Sciences at the University of Adelaide, said the study highlighted an issue that had been known for some time.

Weinstein, who is also president of the Australian Entomological Society, said the "single most important issue in insect conservation is to protect habitat".

The phenomenon of a global insect decline has been "studied in professional circles for many years, which is why the authors have been able to review the existing body of work", he said.

karlwilson@chinadailyapac.com

(China Daily 03/01/2019 page3)