Thursday, October 18, 2018

Things threatened with extinction - black rhino, red panda, our food supply

Look, even if you don’t worry about the black rhino’s fate, you should worry about pollinators going extinct. Those little buggers are responsible for 35% of the world’s plant crops. If the bugs go, we starve. “We are starting to cut down the whole tree [of life], including the branch [humans] are sitting on right now.”

The planet is losing biodiversity. In plain English, critters large and small are disappearing rapidly. To get a sense of the magnitude, the “sixth extinction” we are experiencing (and probably causing) is likely to be on par with the massive extinction that killed off dinosaurs. I raised the alarm back in January 2015 in Signs of the sixth extinction: What happens when apes rule the earth and more recently this month in Thinking in terms of the survival of human society.

Here are two recent features in 538’s significant digits email.

45 percent decrease
Bugs are disappearing. Biologists estimate that the population of invertebrates such as beetles and bees has decreased 45 percent over the past 35 years. The number of flying insects in German nature preserves dropped 76 percent in a similar amount of time. And a new study found the same thing in a “pristine” Puerto Rican national forest. The animals that eat the insects are disappearing, too: The population of the Puerto Rican tody, a bird that eats bugs, dropped by 90 percent. “Holy crap,” an expert in invertebrate conservation said to the Post. [The Washington Post]

The Washington Post sounded a hyperalarm about a threat to human food supply: ’Hyperalarming’ study shows massive insect loss.

Insects around the world are in a crisis, according to a small but growing number of long-term studies showing dramatic declines in invertebrate populations. A new report suggests that the problem is more widespread than scientists realized. Huge numbers of bugs have been lost in a pristine national forest in Puerto Rico, the study found, and the forest’s insect-eating animals have gone missing, too.

In 2014, an international team of biologists estimated that, in the past 35 years, the abundance of invertebrates such as beetles and bees had decreased by 45 percent. In places where long-term insect data are available, mainly in Europe, insect numbers are plummeting. A study last year showed a 76 percent decrease in flying insects in the past few decades in German nature preserves.

The latest report, published Monday in the Proceedings of the National Academy of Sciences, shows that this startling loss of insect abundance extends to the Americas. The study’s authors implicate climate change in the loss of tropical invertebrates.

"This study in PNAS is a real wake-up call — a clarion call — that the phenomenon could be much, much bigger, and across many more ecosystems,” said David Wagner, an expert in invertebrate conservation at the University of Connecticut who was not involved with this research. He added: “This is one of the most disturbing articles I have ever read.”

No matter the cause, all of the scientists agreed that more people should pay attention to the bugpocalypse.

“It’s a very scary thing,” Merrill said, that comes on the heels of a “gloomy, gloomy” U.N. report that estimated the world has little more than a decade left to wrangle climate change under control. But “we can all step up,” he said, by using more fuel-efficient cars and turning off unused electronics. The Portland, Ore.-based Xerces Society, a nonprofit environmental group that promotes insect conservation, recommends planting a garden with native plants that flower throughout the year.

"Unfortunately, we have deaf ears in Washington,” Schowalter said. But those ears will listen at some point, he said, because our food supply will be in jeopardy.

Thirty-five percent of the world’s plant crops require pollination by bees, wasps and other animals. And arthropods are more than just pollinators. They’re the planet’s wee custodians, toiling away in unnoticed or avoided corners. They chew up rotting wood and eat carrion. “And none of us want to have more carcasses around,” Schowalter said. Wild insects provide $57 billion worth of six-legged labor in the United States each year, according to a 2006 estimate.

The loss of insects and arthropods could further rend the rain forest’s food web, Lister warned, causing plant species to go extinct without pollinators. “If the tropical forests go it will be yet another catastrophic failure of the whole Earth system,” he said, “that will feed back on human beings in an almost unimaginable way.”

2.5 billion years’ worth of evolutionary history
According to a new study published in the Proceedings of the National Academy of Sciences, we humans have hastened the extinction of more than 300 species of mammals, thus depriving them of “2.5 billion years’ worth of unique evolutionary history.” Yikes. Sorry about that. The study’s lead author believes we are living in the middle of a sixth mass extinction. For reference, the fifth mass extinction was the one that killed all the dinosaurs. [Huffington Post]

Mammals Will Still Be Recovering From Human Destruction Long After We’re Gone.
A somber new study estimates that it could take several million years for mammal diversity to recover from humanity’s impact.

Humans have helped propel the extinction of more than 300 mammal species — equaling a staggering loss of 2.5 billion years’ worth of unique evolutionary history, according to a grim new study published Monday.

It could take many millions of years for mammals to evolve enough new species to recover from the destruction humans have caused, researchers estimated. The human species, however, won’t likely survive to see the day.

“We are doing something that will last millions of years beyond us,” paleontologist Matt Davis of Denmark’s Aarhus University, who led the new research, told The Guardian of humans’ devastating impact on biodiversity.

The new study, published in the Proceedings of the National Academy of Sciences, estimates that it could take up to 5 to 7 million years for mammal diversity to be restored to the level it was before the arrival of modern humans — and that’s assuming people cease all poaching, pollution and habitat destruction in the next 50 years.

Like many scientists, Davis believes the world is currently in the midst of a sixth mass extinction, also known as the anthropocene extinction or one caused by human activity. Davis told The Atlantic this week that “what we are going through now could have as big an impact as the asteroid” that killed off most of the dinosaurs.

It’s a “pretty scary” situation we’ve created, Davis said. “We are starting to cut down the whole tree [of life], including the branch [humans] are sitting on right now,” he told The Guardian.

Davis said he hopes the new research will help guide conservation work, specifically in helping to identify ― and prioritize ― endangered species with long evolutionary histories. The study, for instance, highlighted the black rhino, red panda and the indri, a large lemur endemic to Madagascar, as endangered animals with particularly long and unique lineages.

“It is much easier to save biodiversity now than to re-evolve it later,” Davis said in a news release.

Ultimately, however, piecemeal conservation efforts won’t be sufficient to stem the tide of extinctions and avert “worst-case scenarios,” Davis stressed.

“It’ll probably get worse, in all honesty,” he told The Atlantic. ”[We need] a massive, ambitious global-scale project that everyone will need to be involved in.”

“It comes down to whether politicians have the political will to make this happen,” he added.


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