Extinction of Australian rodent blamed on climate
The extinction of a tiny brown rodent in Australia is being blamed on climate change and described as a "national tragedy" by environmentalists and scientists who say it could have been avoided.
The Melomys rubicola, or Bramble Cay melomys mosaic-tailed rat, inhabited the small, barren island of Bramble Cay in northeastern Torres Strait near Papua New Guinea.
Professor John Woinarski of Charles Darwin University, an expert on the tiny mammal, said early intervention by the government could have prevented the extinction. He said an effort could have been made years ago as sea levels began to rise due to climate change. Because the island was low lying, it was slowly being eroded by high tides and storm surges, giving this small creature little chance of survival.
Australian Environment Minister Amanda Price announced the rodent's shift from the "endangered" to "extinct" category on Feb 18. Since the European settlement in Australia more than 200 years ago, 34 species of mammals are known to have become extinct, though this is the first attributed to climate change.
The earlier extinctions were mainly due to imports of predator cats and foxes. Yet 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 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 say, 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 in Australia. "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.
Main drivers
The main drivers have been habitat loss and conversion to intensive agriculture and urbanization; pollution, mainly from 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," the study said.
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.
"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."
She said some species will die out, but others will replace them. "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."
