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…]

Bacterial complexity revises ideas about ‘which came first?’

Jordana Cepelewicz writes:

Open a basic biology textbook published decades ago or one published a few months ago, and both will define the two major categories of cells in the same way: Eukaryotes have membrane-bound compartments called organelles, including a nucleus where they store their genetic information, while prokaryotes do not. The distinction is even embedded in their names: In Greek, the word “eukaryote” means “true kernel” (a reference to the nucleus), while “prokaryote” means “before kernel.”

As the evolutionary story is usually told, first came the prokaryotes: the archaea and bacteria, which are often envisioned as simple bags of enzymes without an intricate structure. Then, more than 1.5 billion years ago, eukaryotes evolved, marking the advent of unprecedented cellular complexity and permanently transforming life on Earth, allowing for the rise of animals, plants, fungi and protists. The eukaryotes represented a substantial departure from their predecessors, and the transition from an all-prokaryote world to one that contained eukaryotes is often described as abrupt and explosive.

But this version of events ignores the fact that, for the past few decades, researchers have been quietly uncovering many complex structures within prokaryotes, including membrane-bound organelles. In contrast to eukaryotes, which all have a suite of organelles in common, different groups of prokaryotes showcase their own specialized compartments. One kind of bacterial organelle, discovered in 1979, is essentially a little magnet wrapped in a lipid package; another hosts a series of reactions crucial for energy metabolism; still others serve as small storage units for nutrients. [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…]

The biological origins of rhythm

Ferris Jabr writes:

There are moments when we witness an animal do something so far outside its presumed repertoire of behavior — something so uncannily human — that we can never look at that animal, or ourselves, the same way again. For Irena Schulz, one of those moments happened on an otherwise ordinary day in August, 2007. Schulz lived in Schererville, Ind., where she managed a sanctuary for abandoned parrots. A man named Dane Spudic came by with a young male Eleonora cockatoo called Snowball — a striking creature with milk-white plumage and a sweep of lemon feathers on his nape that fanned into a mohawk when he was excited. Spudic explained that his family could no longer give the increasingly cantankerous Snowball the attention and care he needed.

Oh, and by the way, he added, this bird is an incredible dancer. You should see what he can do. Spudic left behind a burned CD of Snowball’s favorite music.

Schulz was someone who already had a deep appreciation for the intelligence and myriad talents of birds. She had even seen some parrots sway and bob to music. But Spudic’s claims seemed a bit hyperbolic. “We were humoring him, saying, ‘Sure, sure,’” Schulz recalls. Later that evening, she and her husband popped Spudic’s CD into the computer in their living room. “Everybody (Backstreet’s Back)” by The Backstreet Boys started playing. Immediately, Snowball, who was perched on Schulz’s arm, began kicking up his feet and bouncing his head with great zeal — and precision. His movements were synced with the beat. “I couldn’t believe my eyes,” Schulz said. “This bird was like a choreographed phenomenon. He wasn’t just picking up his leg and gingerly putting it down. He was literally foot stomping. I thought, ‘My god — the bird is enjoying this.’”

In time, the whole world would delight in Snowball’s exuberant jig. Schulz posted a video of the dancing parrot on the shelter’s blog, which someone else — possibly someone in Russia — copied to YouTube. It went viral, earning more than 200,000 views in one week. (Today, the video, which is now hosted on Snowball’s official YouTube channel, has more than five million views). Snowball appeared on The Late Show with David Letterman, Good Morning America and numerous other talk shows, and starred in commercials for Taco Bell, Geico and Loka bottled water. [Continue reading…]

We taught bees a simple number language – and they got it

Maybe the differences between human and non-human animals are not as great as we might previously have thought.

By Scarlett Howard, Université de Toulouse III – Paul Sabatier; Adrian Dyer, RMIT University, and Andrew Greentree, RMIT University

Most children learn that written numbers represent quantities in pre-school or junior primary school.

Now our new study shows that honeybees too can learn to match symbols and numerosities, much like we humans do with Arabic and Roman numerals.

[Read more…]

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…]

Green monkeys borrow vervet monkeys’ eagle warning call when threatened by drones reports:

Some 40 years ago, scientists discovered that East African vervet monkeys (Chlorocebus pygerythrus) produce distinct alarm calls when they encounter their three main predators: leopards, snakes and eagles. Their cousins in West Africa, green monkeys (Chlorocebus sabaeus), are also known to cry out at the sight of leopard and snakes, but for some unknown reason, they don’t seem to emit a unique call for birds of prey. A team of researchers recently discovered, however, that the sight of a drone prompts green monkeys to emit an alarm call that is strikingly similar to their vervet cousins’ eagle warning—a finding that suggests such vocalizations are evolutionarily “hard-wired,” the researchers write in Nature Ecology & Evolution.

For the new study, the researchers first tried to get green monkeys in Senegal’s Niokolo-Koba National Park to respond to papermaché models of eagles, without any success.

“Perhaps our artwork was unconvincing,” writes study co-author Julia Fischer, a primatologist at the University of Goettingen in Germany. So the team decided to expose the monkeys to drones, an aerial threat that the animals had not encountered before.

Over the course of several months in 2016 and 2017, the researchers conducted drone flights over three different green monkey groups, using audio equipment to record the sounds they made. Each group was exposed to a drone between one and three times.

When they saw the strange flying object, the monkeys emitted a warning call and ran to hide. Upon conducting acoustic analyses of the drone response call, the researchers found that it was distinct from the monkeys’ leopard and snake warning signal. What’s more, the green monkeys’ drone call was remarkably similar to the vervet monkeys’ eagle alarm—a fascinating discovery, given that green monkeys and vervet monkeys diverged from a common ancestor around 3.5 million years ago. Producing the warning call, perhaps, is not a learned response, but a genetically innate one that has been conserved over a lengthy evolutionary history. [Continue reading…]

The myth of the eight-hour sleep

Stephanie Hegarty writes:

We often worry about lying awake in the middle of the night – but it could be good for you. A growing body of evidence from both science and history suggests that the eight-hour sleep may be unnatural.

In the early 1990s, psychiatrist Thomas Wehr conducted an experiment in which a group of people were plunged into darkness for 14 hours every day for a month.

It took some time for their sleep to regulate but by the fourth week the subjects had settled into a very distinct sleeping pattern. They slept first for four hours, then woke for one or two hours before falling into a second four-hour sleep.

Though sleep scientists were impressed by the study, among the general public the idea that we must sleep for eight consecutive hours persists.

In 2001, historian Roger Ekirch of Virginia Tech published a seminal paper, drawn from 16 years of research, revealing a wealth of historical evidence that humans used to sleep in two distinct chunks. [Continue reading…]

Like humans, ravens mirror the distress they witness in others, study suggests

Katherine J. Wu reports:

Seeing someone else suffer a big disappointment can have a pretty damaging effect on your own morale. That’s definitely the case with people—and it might be true for ravens, too.

New research suggests that, like humans and many other mammals, common ravens (Corvus corax) can read and internalize the emotional states of others. In the study, published today in the journal PNAS, ravens watch their friends grapple with a frustrating task in which they’re denied a tasty treat. Though the onlookers aren’t deprived of anything, they then seem to mirror their partners’ discontent, and start behaving pessimistically themselves.

Unlike people, ravens can’t speak freely about their emotional distress. But these results hint at the tantalizing possibility that humans aren’t alone in their interconnectedness, and could provide early evidence of something akin to empathy in birds.

“This paper is a tremendous step forward in being able to understand the evolutionary roots of empathy,” says Kaeli Swift, an animal behaviorist and corvid expert at the University of Washington who was not involved in the study. “I think it would be too far to say that [this paper shows] ravens are empathetic…but this work could be foundational in eventually arriving at that conclusion.” [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…]