I scream, you scream, bees scream too
News and notes about science
Bees do not scream with their mouths, but with their bodies. When giant hornets draw near and threaten their colony, Asian honeybees cock their abdomens into the air and run while vibrating their wings. The noise can sound eerily like a human scream.
In a paper published in the journal Royal Society Open Science, researchers describe the Asian honeybee’s unique acoustic signal, which is called an anti-predator pipe. The researchers colloquially refer to it as a “bee scream.”
“It’s like a shriek,” said Hongmei Li-byarlay, an entomologist at Central State University in Ohio, who was not involved with the new research. Li-byarlay added that her colleagues who have observed the sounds before compared the noise to “crying.”
The bees make this sound as their nests are threatened by the Vespa soror hornet, which hunts in packs and can dispatch a bee hive in a matter of hours.
Heather Mattila, a behavioral ecologist at Wellesley College in Massachusetts and an author on the study, first heard the bee scream in Vietnam in 2013. She was studying how Asian honeybees smear animal dung around their nests to ward off V. soror and Vespa mandarinia, more famously known as the murder hornet. The behavior showed the bees’ highly evolved social organization, said Lien Thi Phuong Nguyen, a wasp researcher at the Vietnam Academy of Science and Technology in Hanoi and an author on the new paper.
Mattila noticed the hives exploded in sound when V. soror hornets drew near. When she stuck a recorder at the entrance of a hive fringed by hornets, she heard a cacophony of noise.
While she recognized some sounds bees are known to make — hisses, beeps and pipes — Mattila, who has studied European honeybees for 24 years, had never heard anything as loud and frenzied as this.
Mattila brought the recordings back to the United States, where Hannah Kernen, now a research technician at the University of Louisiana at Lafayette, helped analyze the recordings.
The researchers suggest the anti-predator pipe noise functions as an alarm signal, as the production of screams peaked as V. soror hornets hovered outside the colony’s entrance. The data is correlative, so the scream’s exact function is still unknown.
The study shows “how much more complex the organization of collective defense behavior is” in Asian honeybees than previously thought, said Ebi Antony George, a postdoctoral researcher at the University of Lausanne in Switzerland who was not involved with the research. — Sabrina Imbler
How do you see inside a volcano?
Cosmic rays, emanating from all sorts of high-energy entities, constantly bombard Earth’s atmosphere. Their collisions with gases make tiny particles named pions, which speedily decay into muons, subatomic blobs more than 200 times heavier than electrons.
When muons encounter an object, some pass right through while others get stopped in their tracks. That means muons can be used to see inside things that would otherwise be inaccessible, from nuclear reactors to the depths of Egypt’s pyramids.
Scientists have long suspected that this technique, named muography, could be applied to volcanoes, whose anatomies determine when and how they will erupt. And researchers show in a paper, published in the Proceedings of the Royal Society A, that muons have been used to successfully map out some of the arteries and organs of volcanoes around the world, including some of the world’s most hazardous magmatic mountains.
One day, volcanic muography could become the “ultimate detection system for magma,” said Giovanni Leone, a geophysicist at the University of Atacama in Chile and the study’s lead author. He and his colleagues say if you can use muons to track the movement of molten rock in real time, you should be able to forecast an eruption.
Objects are rarely equally dense throughout. That includes volcanoes, which are made of either magma-filled or vacant passageways, a diversity of rock types and countless cracks, crevasses and chasms. To perceive these features, volcanologists could use muon detectors, which range from the size of a suitcase to the area of a small apartment. Scientists could place detectors around a volcano’s flanks, or even fly one around the volcano with a helicopter.
With one detector, you can get a two-dimensional image of a volcano’s innards, “similar to a medical X-ray,” said
David Mahon, a muography researcher at the University of Glasgow who was not involved with the study. “By using multiple detectors positioned around the object, it’s possible to build up a crude 3D image.”
Volcanic muography isn’t flawless. The detectors can only see the parts of the volcano that the muons are penetrating.
And muography is unlikely to make obsolete the other various instruments used to study volcanoes, like seismic waves and satellite observation. “It may not replace existing techniques,” said Vitaly Kudryavtsev, a particle physicist at the University of Sheffield who was not involved with the study. “But it may complementthem.” — Robin George Andrews
Sea lions are crashing golf courses and soccer matches
They have surprised the users of public toilets by their sudden appearances and stopped a children’s soccer match by ambling onto the field. They have frolicked in a community swimming pool and shut down an urban road for weeks. One even gave birth near the 13th hole of a golf course.
Sea lions once flourished along New Zealand’s coasts. But over hundreds of years, human hunting diminished their numbers and drove them to subantarctic islands hundreds of miles south. In recent decades the animals — which are one of the world’s rarest sea lion species — began, slowly and unexpectedly, to return to New Zealand’s mainland.
It is a conservation story of hope and possibility. But with many of the sea lions’ former breeding grounds now populated by humans, scientists say that this time, New Zealanders will have to learn to share.
A study published in Methods in Ecology and Evolution suggests a new way to do that — combining algorithmic modeling that predicts where species will settle with on-the-ground information from those who regularly encounter the wildlife.
Man-made hazards like roads and fences, which do not always appear on maps, can be overlooked in algorithmic modeling, meaning that predictions of where the sea lions will roam can be way off. By working closely with wildlife rangers and sea lion experts, New Zealand’s Department of Conservation, which helped fund the research, hopes to better identify appealing habitats and spot potential threats to the animals in a more accurate and realistic way than before.
“One way it will help is the public awareness and engagement and knowing which communities to target as the population expands,” said Laura Boren, a science adviser for the conservation agency. “We can get people ready for sea lions coming to their town.”
Sea lions have occasionally been deliberately killed, or hit by cars. A monthlong road closure to protect a mother and her pup in January in Dunedin provoked some frustration among locals.
“We need to educate people that these guys are supposed to be here,” said Louise Chilvers, an ecologist at Massey University in New Zealand who was not involved in the research. “They are animals, they are part of the ecosystem. You respect them, and they’ll respect you.”
— Charlotte Graham-mclay
A missing piece of the moon may be following Earth
Space is vast and lonely. It is perfectly understandable, then, that a little rock would decide to tag along with Earth and the moon on their yearly circumnavigation of the sun.
Said rock, 165 feet long, was discovered in 2016 by Hawaii’s PAN-STARRS 1 asteroid-hunting telescope. This eccentric entity’s Hawaiian name, (469219) Kamo‘oalewa, means “wobbling celestial object.” As it repeatedly loops around Earth, this shy body never gets closer than 9 million miles, which is 38 times farther out than the moon. It gets as distant as 25 million miles away before swinging back around for a closer encounter.
Calculations of its orbital waltz indicate that it began trailing our planet in a relatively stable manner about a century ago, and it will continue to pirouette around Earth for several centuries to come. But where did Kamo‘oalewa come from? It is difficult to study the object with telescopes because of its tiny dimensions and its tendency to hide in the shadows.
But in a paper published in Communications Earth & Environment, a team of scientists reported that they might have solved the mystery. By observing Kamo‘oalewa during brief moments when it was illuminated by the sun, astronomers worked out that it appears to be made of the same sort of frozen magmatic matter found on the lunar surface.
“My first reaction to the observations in 2019 was that I probably had made a mistake,” said Benjamin Sharkey, a graduate student at the University of Arizona and the study’s lead author.
Kamo‘oalewa was expected to be composed of minerals typically found on asteroids. But additional observations this spring made it clear that “the data didn’t care what we thought,” Sharkey said. Kamo‘oalewa really did resemble an extremely small version of the moon. Upon making that discovery, he said, “I was both excited and confused.”
Based on its orbit and composition, Kamo‘oalewa may be a fragment of the moon, one shorn off by a meteor impact in the past.
Kamo‘oalewa may sound like a miniature moon, but it isn’t. Unlike the moon, which is gravitationally tied to Earth, Kamo‘oalewa is gravitationally bound to the sun. It is what’s known as a quasi-satellite. Astronomers know of four others lingering in Earth’s vicinity, but Kamo‘oalewa has the most stable orbit. — Robin George Andrews