Tag Archives: Species loss

Millions of species face extinction emergency

An extinction emergency unparalleled in the history of life on Earth could soon overtake millions of species – thanks to us.

LONDON, 8 June, 2020 – More than 500 terrestrial vertebrate species – birds, amphibians, mammals, reptiles – are on the brink of a worldwide extinction emergency. These are animal species with surviving populations of fewer than 1,000 individuals. They are to be found in tropical and subtropical regions and, significantly, they are concentrated in regions heavily affected by human activities.

Extinction is a natural part of the evolutionary process. But the number of simultaneously threatened species, and the link to direct human pressure, adds support for the argument that humanity is now witnessing the sixth, and possibly greatest, mass extinction in the history of life.

The same research has identified 388 vertebrate species with fewer than 5000 individuals in the surviving populations. Of these, more than four-fifths cling to survival in the same threatened regions, and may therefore also be heading for the brink of extinction.

Three distinguished scientists report in the Proceedings of the National Academy of Sciences that they analysed the International Union for the Conservation of Nature’s list of threatened species to identify 29,400 terrestrial vertebrates, 1.7% of which had fewer than 1,000 remaining individuals anywhere in the world.

There are many cases of local extinction: for a mix of reasons, birds or butterflies might disappear from places where they once were many, but continue to flourish in other zones. But too many local extinctions soon amount to global obliteration: the researchers identified 237,000 populations of vertebrates that had vanished since 1900.

Massive impact ahead

They see an ecological catastrophe in the making, and they urge governments and international agencies to act.

“What we do to deal with the current extinction crisis in the next two decades will define the fate of millions of species,” said study lead author Gerardo Ceballos, a senior researcher at the National Autonomous University of Mexico’s Institute of Ecology.

“We are facing our final opportunity to ensure that the many services nature provides us do not get irretrievably sabotaged.”

And his co-author Paul Ehrlich of Stanford University in California said: “When humanity exterminates populations and species of other creatures, it is sawing off the limb on which it is sitting, destroying working parts of our own life-support system.

“The conservation of endangered species should be elevated to a national and global emergency for governments and institutions, equal to climate disruption, to which it is linked.”

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes”

Nearly a fourth of all species on the planet could face extinction. In the course of the 11,000 years since the invention of agriculture human numbers have multiplied from about one million to 7.7 billion, and are rising fast. In the last 450 million years there have been at least five major extinctions, each destroying 70% to 90% of all life on Earth.

Although creatures alive on Earth today account for only 2% of all the creatures that have ever lived, the absolute number of species is greater now than ever before. “It is into such a biologically diverse world that we humans evolved, and such a world that we are destroying,” the authors write.

Extinction may be the greatest environmental problem, because it is irreversible. It is now happening at rates perhaps a thousand times faster than the “background rate” over the last tens of millions of years.

When a species disappears, it takes with it a unique set of biological riches, and – perhaps more dangerously – it creates a loss for other species that may in some way depend upon it. Extinction breeds extinction, the authors argue.

And as plants and animals vanish into oblivion, the biosphere’s capacity to recycle atmosphere, water and nutrients, to pollinate and fertilise, and to dispose of the dead and the waste, is diminished.

‘Ecological zombies’

Ecosystems that support and enrich all life also support and enrich humanity. At one stage 60 million bison maintained the prairie ecosystems of North America and in the course of doing so supported the then Native American population.

By 1884 only 325 individuals were left. The prairies are now largely farmland, and the 4000 surviving wild bison can be considered, the authors say, as “ecological zombies.”

Among other steps, they want to see a halt to the trade in wildlife – thought to be linked to the origins of the Covid-19 pandemic. All three have considerable reputations within science and they have all been making much the same argument for many years.

They calculate that in the last century 543 species of land vertebrate were extinguished. The same number could go in the next two decades. Human action created the problem: only human action can repair the damage.

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes,” said Peter Raven, president emeritus of the Missouri Botanical Garden, the third of the signatories. – Climate News Network

An extinction emergency unparalleled in the history of life on Earth could soon overtake millions of species – thanks to us.

LONDON, 8 June, 2020 – More than 500 terrestrial vertebrate species – birds, amphibians, mammals, reptiles – are on the brink of a worldwide extinction emergency. These are animal species with surviving populations of fewer than 1,000 individuals. They are to be found in tropical and subtropical regions and, significantly, they are concentrated in regions heavily affected by human activities.

Extinction is a natural part of the evolutionary process. But the number of simultaneously threatened species, and the link to direct human pressure, adds support for the argument that humanity is now witnessing the sixth, and possibly greatest, mass extinction in the history of life.

The same research has identified 388 vertebrate species with fewer than 5000 individuals in the surviving populations. Of these, more than four-fifths cling to survival in the same threatened regions, and may therefore also be heading for the brink of extinction.

Three distinguished scientists report in the Proceedings of the National Academy of Sciences that they analysed the International Union for the Conservation of Nature’s list of threatened species to identify 29,400 terrestrial vertebrates, 1.7% of which had fewer than 1,000 remaining individuals anywhere in the world.

There are many cases of local extinction: for a mix of reasons, birds or butterflies might disappear from places where they once were many, but continue to flourish in other zones. But too many local extinctions soon amount to global obliteration: the researchers identified 237,000 populations of vertebrates that had vanished since 1900.

Massive impact ahead

They see an ecological catastrophe in the making, and they urge governments and international agencies to act.

“What we do to deal with the current extinction crisis in the next two decades will define the fate of millions of species,” said study lead author Gerardo Ceballos, a senior researcher at the National Autonomous University of Mexico’s Institute of Ecology.

“We are facing our final opportunity to ensure that the many services nature provides us do not get irretrievably sabotaged.”

And his co-author Paul Ehrlich of Stanford University in California said: “When humanity exterminates populations and species of other creatures, it is sawing off the limb on which it is sitting, destroying working parts of our own life-support system.

“The conservation of endangered species should be elevated to a national and global emergency for governments and institutions, equal to climate disruption, to which it is linked.”

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes”

Nearly a fourth of all species on the planet could face extinction. In the course of the 11,000 years since the invention of agriculture human numbers have multiplied from about one million to 7.7 billion, and are rising fast. In the last 450 million years there have been at least five major extinctions, each destroying 70% to 90% of all life on Earth.

Although creatures alive on Earth today account for only 2% of all the creatures that have ever lived, the absolute number of species is greater now than ever before. “It is into such a biologically diverse world that we humans evolved, and such a world that we are destroying,” the authors write.

Extinction may be the greatest environmental problem, because it is irreversible. It is now happening at rates perhaps a thousand times faster than the “background rate” over the last tens of millions of years.

When a species disappears, it takes with it a unique set of biological riches, and – perhaps more dangerously – it creates a loss for other species that may in some way depend upon it. Extinction breeds extinction, the authors argue.

And as plants and animals vanish into oblivion, the biosphere’s capacity to recycle atmosphere, water and nutrients, to pollinate and fertilise, and to dispose of the dead and the waste, is diminished.

‘Ecological zombies’

Ecosystems that support and enrich all life also support and enrich humanity. At one stage 60 million bison maintained the prairie ecosystems of North America and in the course of doing so supported the then Native American population.

By 1884 only 325 individuals were left. The prairies are now largely farmland, and the 4000 surviving wild bison can be considered, the authors say, as “ecological zombies.”

Among other steps, they want to see a halt to the trade in wildlife – thought to be linked to the origins of the Covid-19 pandemic. All three have considerable reputations within science and they have all been making much the same argument for many years.

They calculate that in the last century 543 species of land vertebrate were extinguished. The same number could go in the next two decades. Human action created the problem: only human action can repair the damage.

“It’s up to us to decide what kind of a world we want to leave to coming generations – a sustainable one, or a desolate one in which the civilisation we have built disintegrates rather than builds on past successes,” said Peter Raven, president emeritus of the Missouri Botanical Garden, the third of the signatories. – Climate News Network

Threats to the insect world are growing

The insect world is dwindling. By 2100, half of all insects could be gone. But there could be gainers too.

LONDON, 30 April, 2020 − The butterflies are quietly flying away, the beetles are buzzing off, and the insect world is shrinking. The Earth’s  land-based insects are in steady decline, their numbers falling by around a quarter every three decades.

And although there could be a whole world of reasons for the global loss of a vital class of animals, European scientists have pinpointed at least one, in one location.

Insect food plants are being lost in the Swiss canton of Zurich, and with them, many of the hoverflies, bumblebees, bees and butterflies that depend on them.

Scientists from Germany and Russia report in the journal Science that they examined the bigger story told by data from 166 surveys of insects and arachnids – that is, not just flies but spiders too – across 1,676 sites worldwide, over periods from 1925 to 2018, and many of them of around 20 years.

Largely missed

They found that those insects that based their lives on land rather than water were slipping away at an average of 0.92% per year. “0.92% might not sound like much, but in fact it means 24% fewer insects in 30 years’ time and 50% fewer over 75 years,” said Roel van Klink of the German Centre for Integrative Biodiversity Research and based at the University of Leipzig.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next. It’s like going back to the place where you grew up. It’s only because you haven’t been there for years that you suddenly realise how much has changed, and all too often not for the better.”

He is not the first to draw attention to insect loss: other groups have warned of dramatic instances of decline and imminent extinction, along with the changes in insect populations and the disappearance of the habitat on which so many species depend.

But the researchers found the decline wasn’t uniform. Those insects – midges and mayflies, for example – that are essentially aquatic were actually increasing in number, on average by more than 1% a year. Flying insects overall however are in decline, and ground-dwellers and grassland insects too are slowly losing the battle for survival, while the numbers of insects in the woodland treetops remain about the same.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next”

Insect declines in Europe and the US West and Midwest were marked, but those insects that live for part of their lives in water in northern Europe and the western US showed a 38% increase over 30 years: this may reflect national and international attempts to limit pollution of the waterways. In both decline and revival, the scientists at work see the impact of human handling of natural habitat.

“Insect populations are like logs of wood that are pushed under water,” Dr van Klink said. “They want to come up while we keep pushing them down. But we can reduce the pressure so they rise again.

“The freshwater insects have shown us this is possible. It’s just not always easy to identify the causes of declines, and thus the most effective measures to reverse them. And these may also differ between locations.”

But within a day of the publication of the Science analysis, German and Swiss scientists had identified the cause of decline in one closely-observed area. They report in the journal Ecological Applications that over the past century there had been an overall decline in wild food plants for all kinds of insects in the Zurich canton.

Urban spread

Wetlands had shrunk by around 90%, the cities and towns had expanded, intensive farming had meant the loss of meadows and farmland habitats.
With help from 250 volunteers, researchers had made detailed studies of the 1,719 seed plant species in 1km plots of land at 3km intervals across the whole canton, between 2012 and 2017.

They then identified 966 of those plants visited by daytime pollinators, and compared their findings with highly-detailed data assembled about the vegetation of the canton before 1930.

Some specialised groups of insects evolved in partnership with equally specialised insects. The scientists found that, for instance, greater knapweed or Centaurea scabiosa was in decline, which was bad news for those bumblebees, bees and butterflies with tongues long enough to reach the nectar. The poisonous plant aconite, or Aconitum napellus, is pollinated by a bumblebee impervious to its toxin. Once again, the loss of floral variety and insect life even in one much-occupied place may not have been obvious.

“It’s hard for us to imagine what vegetation looked like 100 years ago,” said Michael Kessler, a botanist at the University of Zurich. “But our data showed that about half of all species have experienced significant decline in their abundance, while only about 10% of the species have increased.” − Climate News Network

The insect world is dwindling. By 2100, half of all insects could be gone. But there could be gainers too.

LONDON, 30 April, 2020 − The butterflies are quietly flying away, the beetles are buzzing off, and the insect world is shrinking. The Earth’s  land-based insects are in steady decline, their numbers falling by around a quarter every three decades.

And although there could be a whole world of reasons for the global loss of a vital class of animals, European scientists have pinpointed at least one, in one location.

Insect food plants are being lost in the Swiss canton of Zurich, and with them, many of the hoverflies, bumblebees, bees and butterflies that depend on them.

Scientists from Germany and Russia report in the journal Science that they examined the bigger story told by data from 166 surveys of insects and arachnids – that is, not just flies but spiders too – across 1,676 sites worldwide, over periods from 1925 to 2018, and many of them of around 20 years.

Largely missed

They found that those insects that based their lives on land rather than water were slipping away at an average of 0.92% per year. “0.92% might not sound like much, but in fact it means 24% fewer insects in 30 years’ time and 50% fewer over 75 years,” said Roel van Klink of the German Centre for Integrative Biodiversity Research and based at the University of Leipzig.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next. It’s like going back to the place where you grew up. It’s only because you haven’t been there for years that you suddenly realise how much has changed, and all too often not for the better.”

He is not the first to draw attention to insect loss: other groups have warned of dramatic instances of decline and imminent extinction, along with the changes in insect populations and the disappearance of the habitat on which so many species depend.

But the researchers found the decline wasn’t uniform. Those insects – midges and mayflies, for example – that are essentially aquatic were actually increasing in number, on average by more than 1% a year. Flying insects overall however are in decline, and ground-dwellers and grassland insects too are slowly losing the battle for survival, while the numbers of insects in the woodland treetops remain about the same.

“Insect declines happen in a quiet way and we don’t take much notice from one year to the next”

Insect declines in Europe and the US West and Midwest were marked, but those insects that live for part of their lives in water in northern Europe and the western US showed a 38% increase over 30 years: this may reflect national and international attempts to limit pollution of the waterways. In both decline and revival, the scientists at work see the impact of human handling of natural habitat.

“Insect populations are like logs of wood that are pushed under water,” Dr van Klink said. “They want to come up while we keep pushing them down. But we can reduce the pressure so they rise again.

“The freshwater insects have shown us this is possible. It’s just not always easy to identify the causes of declines, and thus the most effective measures to reverse them. And these may also differ between locations.”

But within a day of the publication of the Science analysis, German and Swiss scientists had identified the cause of decline in one closely-observed area. They report in the journal Ecological Applications that over the past century there had been an overall decline in wild food plants for all kinds of insects in the Zurich canton.

Urban spread

Wetlands had shrunk by around 90%, the cities and towns had expanded, intensive farming had meant the loss of meadows and farmland habitats.
With help from 250 volunteers, researchers had made detailed studies of the 1,719 seed plant species in 1km plots of land at 3km intervals across the whole canton, between 2012 and 2017.

They then identified 966 of those plants visited by daytime pollinators, and compared their findings with highly-detailed data assembled about the vegetation of the canton before 1930.

Some specialised groups of insects evolved in partnership with equally specialised insects. The scientists found that, for instance, greater knapweed or Centaurea scabiosa was in decline, which was bad news for those bumblebees, bees and butterflies with tongues long enough to reach the nectar. The poisonous plant aconite, or Aconitum napellus, is pollinated by a bumblebee impervious to its toxin. Once again, the loss of floral variety and insect life even in one much-occupied place may not have been obvious.

“It’s hard for us to imagine what vegetation looked like 100 years ago,” said Michael Kessler, a botanist at the University of Zurich. “But our data showed that about half of all species have experienced significant decline in their abundance, while only about 10% of the species have increased.” − Climate News Network