These animal migrations are huge — and invisible

Carl Zimmer writes:

Last week, ladybugs briefly took over the news cycle.

Meteorologists at the National Weather Service were looking over radar images in California on the night of June 4 when they spotted what looked like a wide swath of rain. But there were no clouds.

The meteorologists contacted an amateur weather-spotter directly under the mysterious disturbance. He wasn’t getting soaked by rain. Instead, he saw ladybugs. Everywhere.

Radar apparently had picked up a cloud of migrating ladybugs spread across 80 miles, with a dense core ten miles wide floating 5,000 feet to 9,000 feet in the air. As giant as the swarm was, the meteorologists lost track of it. The ladybugs disappeared into the night.

Compared to other animal migrations, the migrations of insects are a scientific mystery. It’s easy to spot a herd of wildebeest making its way across the savanna. Insects, even in huge numbers, move from place to place without much notice. One day you look around, and ladybugs are everywhere.

“The migrations themselves are totally invisible,” said Jason Chapman, an ecologist at the University of Exeter in Britain.

Dr. Chapman and his colleagues are using radar to bring insect migrations to light. The scientists help run a unique network of small radar stations in southern England designed to scan the sky 24 hours a day, spotting insects flying overhead.

“These radars are fantastic,” said Dr. Chapman. “We have a lot of information about every individual insect that flies over overhead, including a measure of the shape and a measure of their size.” [Continue reading…]

‘Frightening’ number of plant extinctions found in global survey

The Guardian reports:

Human destruction of the living world is causing a “frightening” number of plant extinctions, according to scientists who have completed the first global analysis of the issue.

They found 571 species had definitely been wiped out since 1750 but with knowledge of many plant species still very limited the true number is likely to be much higher. The researchers said the plant extinction rate was 500 times greater now than before the industrial revolution, and this was also likely to be an underestimate.

“Plants underpin all life on Earth,” said Dr Eimear Nic Lughadha, at the Royal Botanic Gardens, Kew, who was part of the team. “They provide the oxygen we breathe and the food we eat, as well as making up the backbone of the world’s ecosystems – so plant extinction is bad news for all species.”

The number of plants that have disappeared from the wild is more than twice the number of extinct birds, mammals and amphibians combined. The new figure is also four times the number of extinct plants recorded in the International Union for Conservation of Nature’s red list.

“It is way more than we knew and way more than should have gone extinct,” said Dr Maria Vorontsova, also at Kew. “It is frightening not just because of the 571 number but because I think that is a gross underestimate.” [Continue reading…]

In ecology studies and selfless ants, E.O. Wilson finds hope for the future

Claudia Dreifus writes:

No one else in biology has ever had a career quite like that of Edward O. Wilson. One of the world’s leading authorities on ants, an influential evolution theorist, and a prolific, highly honored author, E. O. Wilson—his first name comes and goes from bylines, but the middle initial is ever-present—has over several decades been at the center of scientific controversies that spilled out of the journals and into wider public awareness. Among activists in the environmental movement, Wilson is the elder statesman, the intellectual patriarch whose writings are foundational to the campaign. Soon to celebrate his 90th birthday, he shows no sign of losing his enthusiasm for the fray.

“I’ll tell you something about Ed—he’s a bit of an intellectual grenade thrower,” observed David Sloan Wilson (no relation), an evolutionary biologist at Binghamton University in New York. “He likes to be a provocateur. That’s unusual in someone as established as he is.”

Edward Osborne Wilson began his career as a teenager, by identifying and classifying every ant species in his home state of Alabama. By the age of 29, he had achieved tenure at Harvard University for his work on ants, evolution, and animal behavior. Wider academic fame came to him in the 1960s, when he and the noted community ecologist Robert MacArthur developed the theory of island biogeography, which posited how life established itself on isolated, barren outcroppings of land in the mid-ocean. That study would become a pillar of the then formative discipline of conservation biology. [Continue reading…]

Puffins are starving to death because of climate change

New Scientist reports:

Hundreds of “severely emaciated” puffin carcasses have washed ashore on an Alaskan island, and researchers believe thousands more have died at sea as warming waters continue to shrink their food supply.

Between October 2016 and January 2017, inhabitants of St Paul Island in the Bering sea found the starved bodies of more than 350 seabirds, primarily tufted puffins.

Analysing the location of bird carcasses and wind data, Timothy Jones at the University of Washington in Seattle and his colleagues estimated that between 3000 and 9000 birds died in total.

When they examined some of the bodies, they found no signs of infection or unsafe levels of toxins.

“Collected specimens were severely emaciated, suggesting starvation as the ultimate cause of mortality,” Jones wrote. [Continue reading…]

The fast food of coral reefs

Ed Yong writes:

Although coral reefs are home to bustling communities of gaudy marine life, half the fishes that live there are hardly ever seen. Aptly known as cryptobenthics—literally “hidden bottom-dwellers”—these species are mostly shorter than two inches and usually hidden in crevices. If you snorkel past, they’ll scurry away. But Simon Brandl of Simon Fraser University has made a career of studying them. And he and his team have now shown that cryptobenthics are a crucial component of healthy reefs because they, more so than other fish, are extremely good at dying.

Pretty much every predator on the reef eats cryptobenthics, and a full 70 percent of these tiny morsels are devoured every week. But since they also reproduce, hatch, and grow at equally phenomenal rates, new individuals are constantly replenishing the ones that are consumed. Entire generations can turn over in a matter of weeks. And this extreme life cycle, Brandl found, is the secret engine of the world’s coral reefs, fueling the food webs that allow their inhabitants to flourish in otherwise nutrient-poor waters.

Large, colorful fish such as groupers, wrasses, and parrotfish “are what people focus on because they’re the ones you see when you’re diving,” says Julia Baum, a coral researcher at the University of Victoria. “But I love it when a study like this comes out of the blue and says that maybe these tiny fish might be the ones that are fueling everything else on the reef. That’s very cool.” [Continue reading…]

Humans are killing off most large wild animals as sixth mass extinction advances

The Guardian reports:

Humanity’s ongoing destruction of wildlife will lead to a shrinking of nature, with the average body size of animals falling by a quarter, a study predicts.

The researchers estimate that more than 1,000 larger species of mammals and birds will go extinct in the next century, from rhinos to eagles. They say this could lead to the collapse of ecosystems that humans rely on for food and clean water.

Humans have wiped out most large creatures from all inhabited continents apart from Africa over the last 125,000 years. This annihilation will accelerate rapidly in the coming years, according to the research.

The future extinctions can be avoided if radical action is taken to protect wildlife and restore habitats, and the scientists say the new work can help focus efforts on key species.

Animal populations have fallen by 60% since 1970, suggesting a sixth mass extinction of life on Earth is under way caused by the razing of wild areas, hunting and intensive farming. Scientists said this month that human society was in danger from the decline of the Earth’s natural life-support systems, with half of natural ecosystems now destroyed and a total of a million species at risk of extinction. [Continue reading…]

I’m an evolutionary biologist – here’s why this ancient fungal fossil discovery is so revealing

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Do fungi like this Penicillium mold, which produces the the antibiotic penicillin, trace their origins to an ancestor that lived a billion years ago?
Rattiya Thongdumhyu/Shutterstock.com

By Antonis Rokas, Vanderbilt University

Biologists don’t call them “the hidden kingdom” for nothing. With an estimated 5 million species, only a mere 100,000 fungi are known to scientists. This kingdom, which includes molds, yeasts, rusts and mushrooms, receives far less attention than plants or animals. This is particularly true for fossils of fungi, most of which are discovered while hunting for more charismatic, at least to the eyes of some, plant fossils.

Fungi were key partners of plants during their colonization of land approximately 500 million years ago – an important and well-documented evolutionary transition. Therefore, it is unsurprising that the earliest fungal fossils, found in 450 million-year-old rocks, resemble modern species associated with the roots of plants. But that conflicts with DNA-based estimates, which suggest that fungi originated much earlier – a billion or more years ago. It’s a riddle in the tree of life that evolutionary biologists like me have long been puzzled about.

Fossils versus DNA

For years scientists have tried to reconcile the fungal fossil record with estimates from analyses of fungal DNA. But some of their key morphological characters – that is, the shapes they take – can only be established via microscopic and chemical analyses. That includes the complex networks of microscopic thread-like filaments and cell walls made of chitin, which are also not visible to the naked eye. The effort seemed hopeless, until now.

Corentin Loron, a graduate student at the University of Liege in Belgium and colleagues, discovered microscopic, fossilized specimens of a fungus called Ourasphaira giraldae in shale rock from the Grassy Bay Formation in the Northwest Territories of Canada. Given that Ourasphaira is found on 1,000- to 900-million-year-old rocks, the new fossil pushes back the origin of fungi by half a billion years.

[Read more…]

‘Wood wide web’ — the underground network of microbes that connects trees — mapped for first time

Science reports:

Trees, from the mighty redwoods to slender dogwoods, would be nothing without their microbial sidekicks. Millions of species of fungi and bacteria swap nutrients between soil and the roots of trees, forming a vast, interconnected web of organisms throughout the woods. Now, for the first time, scientists have mapped this “wood wide web” on a global scale, using a database of more than 28,000 tree species living in more than 70 countries.

“I haven’t seen anybody do anything like that before,” says Kathleen Treseder, an ecologist at the University of California, Irvine. “I wish I had thought of it.”

Before scientists could map the forest’s underground ecosystem, they needed to know something more basic: where trees live. Ecologist Thomas Crowther, now at ETH Zurich in Switzerland, gathered vast amounts of data on this starting in 2012, from government agencies and individual scientists who had identified trees and measured their sizes around the world. In 2015, he mapped trees’ global distribution and reported that Earth has about 3 trillion trees.

Inspired by that paper, Kabir Peay, a biologist at Stanford University in Palo Alto, California, emailed Crowther and suggested doing the same for the web of underground organisms that connects forest trees. Each tree in Crowther’s database is closely associated with certain types of microbes. [Continue reading…]

Loss of biodiversity is just as catastrophic as climate change

Robert Watson writes:

A colleague recently described how fish would swim into her clothing when she was a child bathing in the ocean off the coast of Vietnam, but today the fish are gone and her children find the story far-fetched.

Another recalled his experiences just last year in Cape Town – one of the world’s most attractive tourism and leisure destinations – when more than 2 million people faced the nightmare prospect of all taps, in every home and business, running dry.

These instances, on opposite sides of the world, are two faces of the same problem; the relentless pressure we are putting on biodiversity and the contributions that nature makes to our wellbeing, and the way we humans are changing the Earth’s climate.

The rich variety of nature provides us with the food we eat, the water we drink and the air we breathe, and countless moments of personal inspiration spent in forests and mountains, exploring beaches and rivers, or even listening to a simple birdsong in a quiet moment.

We have all assumed that nature would always be here for us and our children. However, our boundless consumption, shortsighted reliance on fossil fuels and our unsustainable use of nature now seriously threaten our future.

Environmentalists, scientists and indigenous peoples have been sounding the alarm for decades. Our understanding of the overexploitation of the planet has advanced with grim, sharp clarity over that time.

We have entered an era of rapidly accelerating species extinction, and are facing the irreversible loss of plant and animal species, habitats and vital crops, while coming face to face with the horrific impacts of global climate change. [Continue reading…]

Biodiversity crisis is about to put humanity at risk, UN scientists to warn

The Guardian reports:

The world’s leading scientists will warn the planet’s life-support systems are approaching a danger zone for humanity when they release the results of the most comprehensive study of life on Earth ever undertaken.

Up to 1m species are at risk of annihilation, many within decades, according to a leaked draft of the global assessment report, which has been compiled over three years by the UN’s leading research body on nature.

The 1,800-page study will show people living today, as well as wildlife and future generations, are at risk unless urgent action is taken to reverse the loss of plants, insects and other creatures on which humanity depends for food, pollination, clean water and a stable climate.

The final wording of the summary for policymakers is being finalised in Paris by a gathering of experts and government representatives before the launch on Monday, but the overall message is already clear, according to Robert Watson, the chair of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

“There is no question we are losing biodiversity at a truly unsustainable rate that will affect human wellbeing both for current and future generations,” he said. “We are in trouble if we don’t act, but there are a range of actions that can be taken to protect nature and meet human goals for health and development.” [Continue reading…]