Humanity is ‘cutting down the tree of life’, warn scientists

The Guardian reports:

Humanity’s ongoing annihilation of wildlife is cutting down the tree of life, including the branch we are sitting on, according to a stark new analysis.

More than 300 different mammal species have been eradicated by human activities. The new research calculates the total unique evolutionary history that has been lost as a result at a startling 2.5bn years.

Furthermore, even if the destruction of wild areas, poaching and pollution were ended within 50 years and extinction rates fell back to natural levels, it would still take 5-7 million years for the natural world to recover.

Many scientists think a sixth mass extinction of life on Earth has begun, propelled by human destruction of wildlife, and 83% of wild mammals have already gone. The new work puts this in the context of the evolution and extinction of species that occurred for billions of years before modern humans arrived.

“We are doing something that will last millions of years beyond us,” said Matt Davis at Aarhus University in Denmark, who led the new research. “It shows the severity of what we are in right now. We’re entering what could be an extinction on the scale of what killed the dinosaurs.

“That is pretty scary. We are starting to cut down the whole tree [of life], including the branch we are sitting on right now.” Ecosystems around the world have already been significantly affected by the extermination of big animals such as mammoths, he said. [Continue reading…]

‘Hyperalarming’ study shows massive insect loss

The Washington Post reports:

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.” [Continue reading…]

Does language spring from the things it describes?

Mark Vernon writes:

In conversation at the Hay Festival in Wales this May, the English poet Simon Armitage made an arresting observation. Discussing the nature of language and why it is so good at capturing the experience of being alive, he said: ‘My feeling is that a lot of the language that we use, and the best language for poetry, comes directly out of the land.’ Armitage was placing himself within the Romantic tradition’s understanding of the origins of language, which argues that words and grammar are not the arbitrary inventions of human brains and minds, but are rather suggested to human beings by nature and the cosmos itself. Language is an excellent way to understand the Universe, because language springs from the things it describes.

The English philosopher Owen Barfield, a member of the Oxford Inklings in the 1930s and ’40s, whose work as a philologist convinced him that the Romantic tradition was broadly right, put it succinctly. Words have soul, he said. They possess a vitality that mirrors the inner life of the world, and this connection is the source of their power. All forms of language implicitly deploy it. Poets are arguably more alert to it because they consciously seek it out.

It’s an insight with radical implications for theories about the origins of language, primarily because the dominant hypotheses in modern science regard words very differently, as soulless signs that act as labels for objects and symbols that facilitate cognitive agility. [Continue reading…]

Scientists fear that insects upon which humans depend are declining

The Associated Press reports:

A staple of summer — swarms of bugs — seems to be a thing of the past. And that’s got scientists worried.

Pesky mosquitoes, disease-carrying ticks, crop-munching aphids and cockroaches are doing just fine. But the more beneficial flying insects of summer — native bees, moths, butterflies, ladybugs, lovebugs, mayflies and fireflies — appear to be less abundant.

Scientists think something is amiss, but they can’t be certain: In the past, they didn’t systematically count the population of flying insects, so they can’t make a proper comparison to today. Nevertheless, they’re pretty sure across the globe there are fewer insects that are crucial to as much as 80 percent of what we eat.

Yes, some insects are pests. But they also pollinate plants, are a key link in the food chain and help decompose life.

“You have total ecosystem collapse if you lose your insects. How much worse can it get than that?” said University of Delaware entomologist Doug Tallamy. If they disappeared, “the world would start to rot.”

He noted Harvard biologist E.O. Wilson once called bugs: “The little things that run the world.” [Continue reading…]

A good place to start raising awareness about the importance of insects for humanity would be to stop calling them “bugs” — and likewise stop calling the soil in which so many of them live, “dirt.”

Why do we love bees but hate wasps?

University College London:

A lack of understanding of the important role of wasps in the ecosystem and economy is a fundamental reason why they are universally despised whereas bees are much loved, according to UCL-led research.

Both bees and wasps are two of humanity’s most ecologically and economically important organisms. They both pollinate our flowers and crops, but wasps also regulate populations of crop pests and insects that carry human diseases.

“It’s clear we have a very different emotional connection to wasps than to bees—we have lived in harmony with bees for a very long time, domesticating some species, but human-wasp interactions are often unpleasant as they ruin picnics and nest in our homes,” explained study author, Dr. Seirian Sumner (UCL Genetics, Evolution & Environment).

“Despite this, we need to actively overhaul the negative image of wasps to protect the ecological benefits they bring to our planet. They are facing a similar decline to bees and that is something the world can’t afford.” [Continue reading…]

A growing wave of extinctions is sweeping across the continents

The Guardian reports:

Spix’s macaw, a brilliant blue species of Brazilian parrot that starred in the children’s animation Rio, has become extinct this century, according to a new assessment of endangered birds.

The macaw is one of eight species, including the poo-uli, the Pernambuco pygmy-owl and the cryptic treehunter, that can be added to the growing list of confirmed or highly likely extinctions, according to a new statistical analysis by BirdLife International.

Historically, most bird extinctions have been small-island species vulnerable to hunting or invasive species but five of these new extinctions have occurred in South America and are attributed by scientists to deforestation.

Stuart Butchart, BirdLife International’s chief scientist, said the new study highlighted that an extinction crisis was now unfolding on large continents, driven by human habitat destruction.

“People think of extinctions and think of the dodo but our analysis shows that extinctions are continuing and accelerating today,” he said. “Historically 90% of bird extinctions have been small populations on remote islands. Our evidence shows there is a growing wave of extinctions washing over the continent driven by habitat loss from unsustainable agriculture, drainage and logging.”

More than 26,000 of the world’s species are now threatened, according to the latest “red list” assessment, with scientists warning that humans are driving a sixth great extinction event. [Continue reading…]

Wildlife preservation depends on saving animals, their habitats, and their cultures

Ed Yong writes:

In the 1800s, there were so many bighorn sheep in Wyoming that when one trapper passed through Jackson Hole, he described “over a thousand sheep in the cliffs above our campsite.” No such sights exist today. The bighorns slowly fell to hunters’ rifles, and to diseases spread from domestic sheep. Most herds were wiped out, and by 1900, a species that once numbered in the millions stood instead in the low thousands.

In the 1940s, the Wyoming Game and Fish Department began trying to move bighorns back into their historic habitats. Those relocations continue today, and they’ve been increasingly successful at restoring the extirpated herds. But the lost animals aren’t just lost bodies. Their knowledge also died with them—and that is not easily replaced.

Bighorn sheep, for example, migrate. They’ll climb for dozens of miles over mountainous terrain in the spring, “surfing” the green waves of newly emerged plants. They learn the best routes from one another, over decades and generations. And for that reason, a bighorn sheep that’s released into unfamiliar terrain is an ecological noob. It’s not the same as an individual that lived in that place its whole life and was led through it by a knowledgeable mother.

“The translocated animals were literally let out of a livestock trailer and started looking around at their new environment,” says Matthew Kauffman from the University of Wyoming. “And they almost entirely failed to migrate.”

Kauffman knows this because the translocated sheep were often fitted with radio collars, allowing him and his colleagues to compare their movements to those of bighorns that lived in the same place for centuries. Within those longstanding herds, between 65 and 100 percent of the sheep migrated. But in the translocated herds, fewer than 9 percent migrated—only the sheep that had been moved into established populations that already knew the land. [Continue reading…]

The human domination of the face of the Earth

By Rhett A. Butler

Despite ongoing deforestation, fires, drought-induced die-offs, and insect outbreaks, the world’s tree cover actually increased by 2.24 million square kilometers — an area the size of Texas and Alaska combined — over the past 35 years, finds a paper published in the journal Nature. But the research also confirms large-scale loss of the planet’s most biodiverse ecosystems, especially tropical forests.

The study, led by Xiao-Peng Song and Matthew Hansen of the University of Maryland, is based on analysis of satellite data from 1982 to 2016. The researchers broke land cover into three categories: tall vegetation consisting of trees of at least five meters (16 feet) in height; short vegetation under five meters in height including shrubs, grass, and agricultural crops; and “bare ground”, including urban areas, sand, tundra, and rock. While the classification may seem simplistic, powerful conclusions can be drawn from the data, including assessing agricultural expansion, climate-driven expansion and contraction of ecosystems, and forest clearing and recovery.

“The results of this study reflect a human-dominated Earth system,” the researchers write. “Direct human action on landscapes is found over large areas on every continent, from intensification and extensification of agriculture to increases in forestry and urban land uses, with implications for the maintenance of ecosystem services.”

[Read more…]

California burning

William Finnegan writes:

On the northwestern edge of Los Angeles, where I grew up, the wildfires came in late summer. We lived in a new subdivision, and behind our house were the hills, golden and parched. We would hose down the wood-shingled roof as fire crews bivouacked in our street. Our neighborhood never burned, but others did. In the Bel Air fire of 1961, nearly five hundred homes burned, including those of Burt Lancaster and Zsa Zsa Gabor. We were all living in the “wildland-urban interface,” as it is now called. More subdivisions were built, farther out, and for my family the wildfire threat receded.

Tens of millions of Americans live in that fire-prone interface today—the number keeps growing—and the wildfire threat has become, for a number of political and environmental reasons, immensely more serious. In LA, fire season now stretches into December, as grimly demonstrated by the wildfires that burned across Southern California in late 2017, including the Thomas Fire, in Santa Barbara County, the largest in the state’s modern history. Nationally, fire seasons are on average seventy-eight days longer than they were in 1970, according to the US Forest Service. Wildfires burn twice as many acres as they did thirty years ago. “Of the ten years with the largest amount of acreage burned in the United States,” Edward Struzik notes in Firestorm: How Wildfire Will Shape Our Future, nine have occurred since 2000. Individual fires, meanwhile, are bigger, hotter, faster, more expensive and difficult to fight, and more destructive than ever before. We have entered the era of the megafire—defined as a wildfire that burns more than 100,000 acres.

In early July 2018, there were twenty-nine large uncontained fires burning across the United States. “We shouldn’t be seeing this type of fire behavior this early in the year,” Chris Anthony, a division chief at the California Department of Forestry and Fire Protection, told The New York Times. It has been an unusually dry winter and spring in much of the West, however, and by the end of June three times as much land had already burned in California as burned in the first half of 2017, which was the state’s worst fire year ever. On July 7, my childhood suburb, Woodland Hills, was 117 degrees. On the UCLA campus, it was 111 degrees. Wildfires broke out in San Diego and up near the Oregon border, where a major blaze closed Interstate 5 and killed one civilian. The governor, Jerry Brown, has declared yet another state of emergency in Santa Barbara County.

How did this happen? One part of the story begins with a 1910 wildfire, known as the Big Burn, that blackened three million acres in Idaho, Montana, and Washington and killed eighty-seven people, most of them firefighters. Horror stories from the Big Burn seized the national imagination, and Theodore Roosevelt, wearing his conservationist’s hat, used the catastrophe to promote the Forest Service, which was then new and already besieged by business interests opposed to public management of valuable woodlands. The Forest Service was suddenly, it seemed, a band of heroic firefighters. Its budget and mission required expansion to prevent another inferno.

The Forest Service, no longer just a land steward, became the federal fire department for the nation’s wildlands. Its policy was total suppression of fires—what became known as the 10 AM rule. Any reported fire would be put out by 10 AM the next day, if possible. Some experienced foresters saw problems with this policy. It spoke soothingly to public fears, but periodic lightning-strike fires are an important feature of many ecosystems, particularly in the American West. Some “light burning,” they suggested, would at least be needed to prevent major fires. William Greeley, the chief of the Forest Service in the 1920s, dismissed this idea as “Paiute forestry.”

But Native Americans had used seasonal burning for many purposes, including hunting, clearing trails, managing crops, stimulating new plant growth, and fireproofing areas around their settlements. [Continue reading…]

Support for the Endangered Species Act remains high as Trump administration and Congress try to gut it

File 20180719 142423 19mmu9o.jpg?ixlib=rb 1.1
The endangered Sierra Nevada bighorn sheep.
USFWS

By Jeremy T. Bruskotter, The Ohio State University; John A Vucetich, Michigan Technological University, and Ramiro Berardo, The Ohio State University

The Endangered Species Act, or “the Act,” is arguably the most important law in the United States for conserving biodiversity and arresting the extinction of species.

Congress passed the ESA in 1973 with strong bipartisan support (the House voted 355-4 in favor of the law) at the behest of a Republican president, Richard Nixon. Nixon had come to believe existing protections for threatened and endangered species were insufficient.

Since its passage, the Act has helped reverse and stop declines in numerous species – from bald eagles to Lake Erie watersnakes – and served as a model for similar laws around the world.

Nevertheless, criticism of the law has been a persistent feature of debates about whether and how to protect imperiled species. That criticism often comes from business and agricultural interests, who argue that the Act’s provisions excessively limit their ability to develop and manage private property.

Such criticisms led to a proposal by the Trump Administration this week to severely curtail the scope of the Act. And they have prompted recent congressional hearings and raised concern that support for the law may be waning.

We are ecologists and social scientists whose work often intersects with the Endangered Species Act. We wanted to know: Is public support for the Act declining? And if so, why?

[Read more…]