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Treefrog ‘fingerprints’ are on their eyeballs

22 October 2026 at 18:06

Our fingerprints, patterns on whale flukes, and fur patterns on cheetahs are examples of the natural ways we can tell one individual animal from another. For an Amazonian treefrog called the egg-eating spiny-backed frog (Osteocephalus oophagus), we need to look into their eyeballs. Fine black radial lines cross their golden irises, and form a pattern similar to our fingerprints. A study recently published in the journal Herpetozoa details the discovery.

The project began with study co-author Mélissa Peignier, a behavioral ecologist at the University of Bern in Switzerland, admiring frog eyes. 

“At the time, I was doing my PhD, studying Allobates femoralis in the field in French Guiana,” Peignier said in a statement. “My first reaction was simply something along the lines of, ‘Wow, what beautiful eyes!’ That initial curiosity gradually turned into a genuine interest in the species, and I realised how little we actually know about them.”

a green frog sitting on a leaf
Osteocephalus oophagus in situ. Photographed in French Guiana (4°02’N, 52°41’W; ) between March and May 2021. Image: Mélissa Peignier et al., 2026.

There was also an ethical component. One of the standard ways to tell amphibians apart from one another is toe-clipping, where a section or all of a single toe is removed. This procedure can affect their survival, physiology, and behavior. 

“Other studies have used toe-clipping, which involves removing some of the digits. Personally, I was uncomfortable with this approach, especially given that these are arboreal frogs that rely on their limbs to climb trees.”

a green frog on a stone
Osteocephalus oophagus in situ. Photographed in French Guiana (4°02’N, 52°41’W; ) between March and May 2021. Image: Mélissa Peignier et al., 2026.

Looking for other markings could offer a more humane solution and a way to observe the animals natural behavior unimpeded.

For this study, fieldwork took place over three rainy seasons (2021 to 2023) on a river island in the Nouragues Nature Reserve in French Guiana. They identified 103 individual frogs over the course of the study.

Example of the diversity of iris patterns from eight Osteocephalus oophagus individuals photographed in French Guiana (4°02’N, 52°41’W; Bongers et al. 2001) between March and May 2021, 2022, and 2023. Image: Mélissa Peignier et al., 2026.
Example of the diversity of iris patterns from eight Osteocephalus oophagus individuals photographed in French Guiana (4°02’N, 52°41’W; Bongers et al. 2001) between March and May 2021, 2022, and 2023. Image: Mélissa Peignier et al., 2026.

During their later encounters, the team took pictures of each animal’s eyes without touching it and then compared the images with a reference library. This way, the recognised frogs were left undisturbed and their eyes appeared in their more natural state. The identifications were then independently verified using Wild-ID, a software package that analyzes photographic markings in animals.

They found highly distinctive iris patterns. Within one season, between 56 and 80 percent of the frogs were recaptured and reliably re-identified. According to the team, this indicates that the patterns on their eyes remain stable enough to monitor the frog in the short-term. Photographs could even be taken of frogs while in their mating embrace (called amplexus) without disrupting them. The team hopes that this method will spread. 

two frogs with one on top of the other's back
Osteocephalus oophagus in situ. Photographed in French Guiana (4°02’N, 52°41’W; ) between March and May 2021. These frogs are in amplexus, or their mating embrace. Image: Mélissa Peignier et al., 2026.

“In a world where biodiversity is declining at an alarming rate, it is essential that we minimise our impact on the animals we study,” added Peignier. “If we can reliably identify individuals using naturally occurring features, we may be able to reduce the need for more invasive marking techniques while still collecting the data needed to answer important scientific questions.”

While the reliability of the eye markings will vary between species, and should be done case by case, the team sees considerable promise for amphibians with complex irises. And working with them offers its own benefits. 

“Honestly, the frogs themselves are incredibly beautiful and surprisingly chill, which makes working with them a real pleasure,” Peignier said. 

The post Treefrog ‘fingerprints’ are on their eyeballs appeared first on Popular Science.

What night is van Gogh’s ‘The Starry Night’? New analysis says it’s in July.

22 October 2026 at 16:00

The swirling bluish-white mistrals, towering cypress trees, and glittery stars in Vincent van Gogh’s “The Starry Night” (1889) have captivated our imaginations for generations. Despite never selling a painting during his lifetime, van Gogh’s “The Starry Night” has since inspired a hit song in 1972, draws visitors to the Museum of Modern Art in New York City, and adorns everything from journals to scarves and tote bags.

But what particular night above Saint-Rémy-de-Provence, France, did the troubled post-impressionist painter actually put on the canvas? A new analysis points to July 22, 1889. During the early morning hours at that time of year, a waning crescent moon, the planet Venus, and the Hyades star cluster in Taurus appeared close together—all of which are seen in the painting. A study published today in the journal Scientific Reports details the findings. 

The story behind ‘The Starry Night’

According to the Metropolitan Museum of Art, van Gogh was inspired by the view from his window at the Saint-Paul-de-Mausole asylum in southern France. He spent twelve months there 1889–1890, seeking reprieve from his mental illnesses and was also diagnosed with a form of epilepsy. 

Like many of his paintings that year, “The Starry Night” was created in several sessions during the day, under different weather conditions. The village nestled below the hills was also based on other views, and could not be seen from his window. Although van Gogh reconstructed some of the features in the night sky as he saw them, he also altered the celestial shapes and added a sense of glow.

“Van Gogh assigned an emotional language to night and nature that took them far from their actual appearances,” the museum writes. “Dominated by vivid blues and yellows applied with gestural verve and immediacy, ‘The Starry Night’ also demonstrates how inseparable van Gogh’s vision was from the new procedures of painting he had devised, in which color and paint describe a world outside the artwork even as they telegraph their own status as, merely, color and paint.”

Looking to the stars

Using astronomy to pinpoint which day inspired the painting began with UCLA art historian Albert Boime in 1984 and Harvard University astronomer and astrophysicist Charles Whitney in 1986. The two scholars reached conflicting conclusions, and neither of them displaced the prevailing religious and symbolic interpretations of the painting. 

Historically, the painting has been dated based on a letter van Gogh wrote to his brother Theo around June 18, 1889. However, the waning gibbous moon from mid-June does not account for the slender crescent seen in the painting. By July 22, 1889, the Hyades star cluster rose in the eastern sky alongside Venus, and the moon’s shape looked closer to the crescent on the canvas. This new study uses observational geometry to find an answer.

“To an observational astronomer, the cluster of stars in ‘The Starry Night’ is the Hyades in Taurus,” said study co-author Elijah Jeong-hyun Kim.  “But the moment I read the earlier studies explaining it as Aries, I heard the painting calling to me.” Kim is the CEO at South Korean robotic telescope company SLLAB and a PhD candidate at Kyung Hee University.

For this research, the team combined astronomical simulations and measurements of star positions, with historical weather records, and van Gogh’s own letters. They also used earlier sketches of the landscape to reconstruct the narrow field of view represented in “The Starry Night.”

(A) The central cluster of stars in “The Starry Night” (1889), left, and the Hyades cluster in Taurus, center. At right, the five stars in the painting (orange) are overlaid on the real stars (blue) after matching for size, orientation and position; red dashed lines show the residual differences. (B) The stars in “Café Terrace at Night” (1888), left, and the stars around the Summer Triangle, center. The panel at right follows the same layout as in (A). Image: Kim et al., Scientific Reports (2026), Figs. 2, 4 and S1.
(A) The central cluster of stars in “The Starry Night” (1889), left, and the Hyades cluster in Taurus, center. At right, the five stars in the painting (orange) are overlaid on the real stars (blue) after matching for size, orientation and position; red dashed lines show the residual differences. (B) The stars in “Café Terrace at Night” (1888), left, and the stars around the Summer Triangle, center. The panel at right follows the same layout as in (A). Image: Kim et al., Scientific Reports (2026), Figs. 2, 4 and S1.

According to the team, the crescent moon, Venus, and the Hyades star cluster in the constellation Taurus would have been visible around dawn on July 22, 1889. This configuration generally corresponds to what is portrayed in the painting. Weather records suggest that the night sky around July 22 would have been clear enough for this astronomical arrangement to be visible. Additionally, the frequent mentions of cicadas in van Gogh’s letters suggest that the region was seeing a period of hot weather, which matches the recorded temperatures in July 1889 better than in June.

The team also verified that the painter’s field of view in another painting titled “Starry Night over the Rhône” (1888) with photographs taken on site was painted when the sky was in Aries. Using the same method, the team also believes that the stars in “Café Terrace at Night” (1888) may be the Summer Triangle.

“I hope this work prompts a renewed, multidisciplinary look at the sequence and working methods of the Saint-Rémy paintings, and at Van Gogh’s movements that summer,” Kim said. “Our conversation with Van Gogh’s other skies is still ongoing. We plan to tell those stories one by one.”

The post What night is van Gogh’s ‘The Starry Night’? New analysis says it’s in July. appeared first on Popular Science.

Baby manta rays stick to the shallows to avoid sharks and orca

22 October 2026 at 05:00

Before giant manta rays (Mobula birostris) can grow to up to 30 feet long and 4,409 pounds, they must start small like most living things. Giant manta ray babies (called pups) in Central America don’t have their size to protect them from orca whales (Orcinus orca) and the numerous sharks in the open ocean. Their solution—sticking to the coast, where there is plenty of food to help them grow and defend themselves. A new study published today in the journal Frontiers in Fish Science details the baby rays’ behavior. 

“We show that manta rays’ lifestyle isn’t a one-size-fits-all behavior. Giant manta rays in Central America undergo a dramatic shift in space use as they mature,” Jeffry Madrigal-Mesén, a study co-author and project leader of Mantas Costa Rica, said in a statement. “Juveniles remained strictly within shallow nearshore waters that serve as coastal refuges, but most of the tracked adults executed long-distance transboundary migrations along the continental shelf break into Central America.”

a manta ray swimming
Puntitos, one of the immature mantas the scientists followed. Image: Jeffry Madrigal.

Where the pups grow

In the study, the team used multiple methods to track and identify mantas at five locations between 2018 and 2025. Acoustic telemetry uses underwater sound pulses to monitor fish movements and allowed the team to track 59 individual rays. With satellite telemetry, transmitters track movement and behavior from a distance and helped the team track large-scale movements of 12 individuals. Lastly, photo identification helped to identify individual manta rays.

“If we hadn’t used all three technologies together, we simply wouldn’t have been able to piece this puzzle together,” explained Madrigal-Mesén. “Combining these tools turned fragmented data into a unified, undeniable story.”

The team ended up with a dataset of over 12,000 detections. The data showed that young mantas (those with a body about 10 feet or less) stick to shallow coastal refuges. In these more shallow spots, the pups have a safe place that doesn’t overlap with their predators’ hunting grounds. They have plenty of food and places to hide, and even get essential services like cleaning from reefs.

“Mature adults can rely on their massive body size and their ability to dive deep to evade threats. But juveniles don’t have that luxury,” said Madrigal-Mesén. “What is truly amazing is seeing how strictly young manta rays stick to coastal waters as long-term refuges. We see the same individuals more often than once a year. In fact, just recently, they were sighted again at the exact same tagging location. It is always a joy to see them again—they have truly become a part of the family.”

a manta ray swimming by a diver
Manta ray in close proximity to a diver. Image: Jeffry Madrigal.

By comparison, nine mature mantas in the study went on expansive migrations along the continental shelf break. One manta ray nicknamed Mickey Mouse because of a spot pattern on his belly had movements that suggest the fish also continue to display loyalty to a particular site once they grow up. Unusually approachable for a manta, Mickey Mouse allowed the team tag him multiple times over several years, which provided a continuous dataset. In 2020, he logged 462 acoustic detections at a coastal hub called El Secreto. He returned to the same shelf in 2023, and stayed there for 38 days.

“Nearshore cleaning stations transcend basic hygienic function; they act as primary social hubs where courtship and reproductive interactions take place,” said Madrigal-Mesén. “Returning to a predictable coastal depot allows mature rays to prioritize social and cleaning needs before undertaking large-scale regional migrations.”

Traveling the manta swimway—safely

Once they leave coastal regions, adult manta rays face different dangers. Coastal areas are often legally protected marine reserves, but the open ocean is another story. They no longer have legal protection and are exposed to dangers from industrial fisheries and vessel strikes.

According to the team, this shows that marine protected areas alone are not enough to protect this highly mobile species as it swims across Central America. They say that multi-national “conservation swimways”  that link the domestic juvenile coastal refuges with adult migratory corridors could help keep the endangered rays safe. 

“This study opens a new chapter for manta ray research in Central America,” Madrigal-Mesén concluded. “We hope it sparks fresh enthusiasm and encourages future collaborators to join us in executing the new ideas and research projects we have planned for the conservation of this species.”

The post Baby manta rays stick to the shallows to avoid sharks and orca appeared first on Popular Science.

Monkeys also avoid germs after viral outbreaks 

21 October 2026 at 00:05

When a new disease emerges, things can get a little weird. We start to clean groceries with antibacterial wipes, the sound of a sneeze can trigger our fight-or-flight response, and we generally become more cautious. Humans may not be the only primate species that change their behavior in the face of disease. 

According to a study published today in the journal Royal Society Open Science, Japanese macaques (Macaca fuscata) that lived through a deadly outbreak in 2020 became noticeably more cautious about food that appeared contaminated, even though this disease was not spread by food or feces. This indicates that purposefully shifting behavior to avoid a pathogen can be shaped by our appearance and that disgust may have deep evolutionary roots. It also sheds light on the behavioral immune system—a collection of behaviors that help animals avoid an infection before the biological immune systems respond.

“We can show now, in non-human primates, that this is the same for them,” Federico Rossano, a study co-author and cognitive psychologist at the University of California San Diego, said in a statement. “Even with no knowledge of how disease is transmitted, being exposed to others getting sick and dying changes the likelihood of engaging in behaviors that potentially could lead to some form of sickness.”

2020 was a big year for outbreaks

In 2020, the staff at a primate sanctuary in southern Texas confirmed the presence of simian retrovirus Type II. This disease can cause AIDS-like immunodeficiency and is primarily transmitted through bites and scratches. It caused severe illness and death in some of the monkeys. The sanctuary staff separated the groups and implemented testing and quarantine measures in response to the outbreak. Since the groups live in separate enclosures, scientists then had the chance to compare animals with similar backgrounds that had experienced very different social and disease environments. 

In total, three groups of monkeys experienced the outbreak while one had not. The team tested 

55 macaques to see how they responded to a choice between food that was put on a clean wooden surface and food placed on a surface covered with real macaque feces. The food with the feces was sealed under a layer of clear epoxy, so that the monkeys could see the food and poop without risking infection.

In the group that had been exposed to the outbreak, some of the individuals had been infected while others had lived alongside sick monkeys without getting sick. This allowed the researchers to question if experiencing an outbreak without getting infected could change the macaque’s behavior. To test that further, the clean surface was replaced with a brightly colored kitchen sponge in some of the scenarios to see if the animals were just avoiding unfamiliar objects. 

Previous studies found that macaques aren’t necessarily deterred by contamination—as long as the payoff is tempting. When presented with a favorite treat (such as a peanut) wild Japanese macaques would still eat food from a surface covered in feces, but will avoid it for food like grains of wheat.

Continued caution

The team found that macaques from groups that went through the outbreak were far less likely to eat the food from the contaminated surface. They ate from the fake contaminated surface in only 47 percent of trials. The monkeys that did not experience the outbreak ate from the potentially contaminated surface in 79 percent of trials.

The monkeys from outbreak-exposed groups also behaved similarly whether or not they themselves had been infected. According to the team, this suggests the behavioral change was associated with their experiencing living through the outbreak, instead of actually getting sick

“Groups have histories, and those histories show up in behavior,” added study co-author and UC San Diego cognitive psychologist Stephan Kaufhold. “Living through the disease outbreak appears to have made those monkey groups more cautious around food that looks contaminated.”

The virus was spread through blood or saliva from bites and scratches, and not through contaminated food. Interestingly, the macaques who saw their fellow primates get sick, were more reluctant to eat food placed on a surface that visually suggested contamination in some of the tests.

Disgust’s evolution

In addition to shedding light on how illness affects primate behavior, it also offers insight into the evolution of disgust. The team did not measure disgust directly, but found that monkey’s avoidance of potential sources of infection can change with their experience, similar to what humans do.

Human disgust is believed to play an important role in protecting us from pathogens. We recoil from the smell and sight of poop, spoiled food, and other potential sources of infection. Our sensitivity to those cues can also change depending on context.

Since primates are capable of social learning, the team believes that heightened pathogen avoidance could be learned from other members in the group and persist over time. Future studies could see if newly introduced animals adopt the behavior of a group that has already experienced an outbreak.

The post Monkeys also avoid germs after viral outbreaks  appeared first on Popular Science.

Bat Beauty Contest returns October 24

20 October 2026 at 15:30

With Alaska’s fat bears done packing on their winter weight and spooky season in full swing, it’s time to turn our collective animal-loving attention to a smaller mammal—bats. The Bureau of Land Management’s (BLM) annual Bat Beauty Contest returns on October 24 and promises “plenty of batty puns.”

Beginning Saturday, October 24, BLM will post photos of the competitors to their Facebook and Instagram accounts and ask you to vote for the best-looking one. All of the competing bats are part of wild populations that live on land managed by the public agency and are photographed by wildlife technicians. The winner will be announced (appropriately) on Saturday, October 31.

The bats in this competition are known for their squishy faces and clever names. In 2024, a hoary bat (Lasiurus cinereus) from Oregon named Hoary Potter took the crown. Other contestants included a long-eared myotis (Myotis evotis) named Honey Bunches of MyOtis, a myotis bat (Myotis myotis) named Robert Battinson, and western small-footed bats (Myotis ciliolabrum) named Batt Damon and Batlor Swift. The contest was not held in 2025 due to the 43-day-long federal government shutdown. 

a bat next to a logo that says bat week
A hoary bat at Isle Royale National Park in Michigan. Image: NPS Photo/Bat Conservation International.

The contest is not all bat puns and a way to keep the spirit of Fat Bear Week alive. It falls during Bat Week (October 24-31). Bat Week raises awareness about the Earth’s only flying mammal. More than just a Halloween symbol, bats play a critical ecological role as plant pollinators and through eating insects that can threaten crops and forests around the world. According to Bat Week, one bat can eat up to its body weight in insects every night. Only three species of bats eat animal blood, with two specializing in bird blood. Female lesser long-nosed bats even make tequila possible. Every spring, they migrate from south-central Mexico up to the southwestern United States, following “nectar corridors” of columnar cacti and agave plants. They pollinate agave plants, which are then used to make tequila and mezcal. When they feed on cactus fruits and nectar, they may also help disperse cacti seeds. Other bats eat pollen, nectar, or fruit.

Bats are increasingly threatened due to habitat loss, light pollution, and diseases like white-nose syndrome. This fungal disease infects the skin of the muzzle, ears, and wings of hibernating bats. In about 20 years, it has killed millions of bats across North America and affects about half of the species on the continent. Bats also are often misunderstood as carriers of diseases such as rabies. 

The planet is home to over 1,400 species of bats, and they make up almost 20 percent of all mammal species. Bats also can be found almost everywhere on Earth, even in desert and polar regions. To look up which bat species live near you, you can use Bat Week’s state bat database.

Stay tuned for more Bat Week updates!

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Astronomers discover first green star and the reddest star ever recorded

15 October 2026 at 15:26

Despite the name, the universe’s white dwarfs can glow in a wide range of colors—even green. For the first time, astronomers have spotted a star that appears green to the human eye, and the reddest ever recorded. These outlier stars help explain how certain white dwarf stars would shine in green, pink, cyan, yellow, and purple if we actually saw them up close in space. These colorful findings are described in a study recently published in the journal RAS Techniques and Instruments.

Looking for the ‘perfect radiator’

White dwarf stars are the dense remnants left behind after stars like our sun reach the end of their lifespan. For most stars, their color gives a hint to their temperature. Cooler stars appear orange, warm stars like our sun look white. The hottest glow pale blue, similar to how a blacksmith’s iron will go from red to orange to white hot. Astronomers believed that white dwarfs followed this same rule. They even earned their name after the earliest examples were surprisingly hot and glowed in a white/pale blue. 

“Most stars, including most white dwarfs, behave like ‘perfect radiators,’ so their colour is set almost entirely by temperature. But nobody had really looked into what else might be possible for white dwarfs,” Mark Hollands, a study co-author and astronomer at the University of Warwick in England, said in a statement. “It turns out these incredibly dense stars can produce colours nobody expected, and some of them genuinely surprised me.” 

According to the team, the key to these colors is density. The atmospheres surrounding the coolest white dwarfs can reach about the same density as water (roughly 1 gram per cubic centimeter). They are also millions of times denser than the sun’s photosphere, the lowest layer of its atmosphere. Under these higher density conditions, any trace elements present (carbon, calcium, sodium, etc.) interact with the surrounding dense helium plasma. As they interact with the plasma, they can absorb light across a wider spectrum of colors than they would at lower densities. This then shifts the star’s color away from the more typical orange, white, and blue.

Unfortunately, no white dwarf sky is close enough for its color to be seen directly. Instead, the team calculated their color from data astronomers routinely collect—a star’s spectrum. The spectrum is a “fingerprint” that’s produced when starlight splits apart by wavelength, similar to how a prism splits sunlight into a rainbow. Astronomers ran these spectra through a computer model of what colors human vision can see to check what color a star’s light would appear to our eyes. 

Color-accurate simulated images of white dwarfs. Top Left panels: Sirius B is the nearest white dwarf to the Solar System, with a hot hydrogen atmosphere, resulting in a pale blue colour. WDJ1147-7449 is instead among the coolest nearby white dwarfs, giving it a featureless spectrum and an orange appearance. Top Right panels: Convective envelopes in these cool white dwarfs have dredged up carbon from their cores into their dense helium-dominated atmospheres, forming diatomic carbon molecules that lead to various pink hues. Bottom panels: Accretion of rocky debris from the white dwarf planetary systems enriches their cool helium atmospheres with elements such as calcium, magnesium, and sodium. The varying amounts/compositions of accreted material and white dwarf temperatures allow for a diverse array of colours, including green. In reality all stars would be many millions of times brighter than what can be shown on-screen. Image: Mark Hollands/University of Warwick
Color-accurate simulated images of white dwarfs. Top Left panels: Sirius B is the nearest white dwarf to the Solar System, with a hot hydrogen atmosphere, resulting in a pale blue colour. WDJ1147-7449 is instead among the coolest nearby white dwarfs, giving it a featureless spectrum and an orange appearance. Top Right panels: Convective envelopes in these cool white dwarfs have dredged up carbon from their cores into their dense helium-dominated atmospheres, forming diatomic carbon molecules that lead to various pink hues. Bottom panels: Accretion of rocky debris from the white dwarf planetary systems enriches their cool helium atmospheres with elements such as calcium, magnesium, and sodium. The varying amounts/compositions of accreted material and white dwarf temperatures allow for a diverse array of colours, including green. In reality all stars would be many millions of times brighter than what can be shown on-screen. Image: Mark Hollands/University of Warwick

The first green and the reddest red

The team applied this method to several white dwarfs across the cosmos. They found that their colors fall into distinct groups linked to what makes up a star’s atmosphere. Carbon-rich white dwarfs generally appear pink or purple. Stars enriched with debris from busted asteroids and comets, the remains of old planetary systems, tend to be more yellow. Cooler white dwarfs with atmospheres of mixed hydrogen and helium show a more cyan or pale blue tinge. This cyan-pale blue is caused by hydrogen molecules colliding with helium atoms inside their ultra-dense atmospheres.  

The most striking example is WD J1330+6435. This star is about 7,232 degrees Fahrenheit (4,000 degrees Celsius) and around 284 light-years away from Earth. Over time, it has gathered rocky material from its planetary system. All of this extra material enriched its atmosphere with calcium, lithium, and sodium. The result—a chartreuse green appearance in the team’s models. As far as the researchers are aware, no other star (living or dead) has ever been credibly reported as green.

Enriched from above: The cool white dwarf WDJ1330+6435 has accreted sodium-rich rocky material from its planetary system into its atmosphere. The immense atmospheric density causes the sodium to absorb light over broad range of yellow, orange, and red wavelengths, giving the WDJ1330+6435 a ghostly green appearance. Image: Mark A Garlick/University of Warwick.
Enriched from above: The cool white dwarf WDJ1330+6435 has accreted sodium-rich rocky material from its planetary system into its atmosphere. The immense atmospheric density causes the sodium to absorb light over broad range of yellow, orange, and red wavelengths, giving the WDJ1330+6435 a ghostly green appearance. Image: Mark A Garlick/University of Warwick.

“The traces of sodium in the atmosphere of this white dwarf absorb the orange part of the spectrum, leaving behind a ghostly green glow,” added Hollands. “Imagine standing on a planet and looking up at a green star. It feels like something out of science fiction.” 

On the opposite end of the spectrum, the team identified what could be the reddest star ever recorded—WD J1011+2845. This white dwarf is only 48 light-years away from Earth, and has a deep convection zone. This zone is full of carbon that’s been lifted up from the star’s core to its surface. The carbon molecules then distort the star’s light so much that almost all of it is squeezed into wavelengths beyond 600 nanometres. This wavelength produces an unusual deep salmon-pink glow.

Enriched from below: The cool white dwarf WDJ0902+2010 has a deep convection zone within its helium dominated outer envelope. The convection zone has reached the white dwarf core, lifting interior carbon to the surface, and forming carbon molecules. These C2 molecules strongly absorb light across the optical range, including blue, green, and yellow wavelengths, resulting in WDJ0902+2010 appearing pink to the human eye. Image: Mark A. Garlick/University of Warwick.
Enriched from below: The cool white dwarf WDJ0902+2010 has a deep convection zone within its helium dominated outer envelope. The convection zone has reached the white dwarf core, lifting interior carbon to the surface, and forming carbon molecules. These C2 molecules strongly absorb light across the optical range, including blue, green, and yellow wavelengths, resulting in WDJ0902+2010 appearing pink to the human eye. Image: Mark A. Garlick/University of Warwick.

What are the odds?

The team also studied 151 white dwarfs located within about 65 light-years (20 parsecs) from Earth. Only five of these showed unusual colors, two yellow and three pink. This suggests that about 1 in 30 of the universe’s white dwarfs shine with an unusually colored light. 

The team then measured the color temperature of the remaining 146 white dwarfs. Color temperature is commonly used to describe light bulbs using degrees Kelvin—warm white at 3,000K, cool white at 6,000 K, etc. The median color temperature of the sample was approximately 6,800K, which our eyes perceive as white. This measurement corrects a common misconception that white dwarfs are typically blue. The hotter and bluer white dwarfs are mostly brighter, so they can be seen from further away and are over-represented in surveys that only look at a star’s brightness.

“One in thirty might not sound like a huge fraction, but across the entire population of white dwarfs in the Universe, that is still a lot of oddly coloured stars out there,” added study co-author and University of Warwick astronomer Boris Gänsicke. “Yet if we take the median across a representative population of white dwarfs, we found that the average white dwarf really is white.”

The post Astronomers discover first green star and the reddest star ever recorded appeared first on Popular Science.

Jackie the bald eagle’s final cause of death revealed

15 October 2026 at 12:41

The Ojai Raptor Center released the final necropsy results for Jackie, an internet-famous bald eagle mother who was in their care this summer. Jackie was brought into the bird rehabilitation center weak and dehydrated following an altercation with another eagle in July. 

Officially designated as Patient 26-519, Jackie’s necropsy revealed a “complex and unusual disease process involving severe, chronic inflammation and ulceration of the stomach, persistent internal bleeding, anemia and secondary bacterial sepsis.” She was also diagnosed with Highly Pathogenic Avian Influenza (HPAI) commonly called bird flu, which was behind severe stomach ulceration. Raptors (eagles, hawks, falcons, owls, etc.) are highly susceptible to the virus 

All of these medical complications developed over time and ultimately contributed to her death on August 10.

“These findings have helped connect many of the pieces we were seeing throughout her hospitalization and provided a better understanding of the challenges she faced,” the Ojai Raptor Center wrote. “We are grateful to the many veterinary specialists, laboratories, wildlife agencies and partner organizations who worked alongside our team to understand her illness and provide her with the best possible care. Caring for her was an extraordinary privilege for our entire team.”

The full report can be read in Jackie’s veterinary medical journal. The necropsy was preformed by veterinary pathologists at the San Diego Zoo Wildlife Alliance.

Friends of Big Bear Valley (FOBBV), the non-profit organization that runs the live cameras where viewers from all over the world watched Jackie and her partner Shadow, said that they will follow up with their thoughts once their team has had time to process the report.

“The story of the Big Bear bald eagle reflects the powerful connection people feel to these iconic birds,” California Department of Fish and Wildlife Director Meghan Hertel added. “We’re grateful to everyone who cared for her and worked to support her well-being.  Understanding the results of these tests is an important part of learning from this case and can help inform the care and treatment of other eagles and wildlife in the future.”

a bald eagle standing on a perch inside
Jackie on a perch at the Ojai Raptor Center in July. Image: Ojai Raptor Center.

Jackie’s story

Jackie was born, raised, and lived in Big Bear Valley in Southern California. Prior to the 2011-2012 nesting season, no bald eagle chicks were known to have ever hatched in Big Bear Valley. Then came Jackie, named after a forest ranger and born to parents Ricky and Lucy in 2012. 

During the 2016-2017 nesting season, Jackie took over a nest where Friends of Big Bear Valley (FOBBV) had a camera stationed. In 2018, she had two chicks named Stormy and Big Bear Baby (or BBB) with her first mate, Mr. B. 

Her long-time partner Shadow entered the picture in summer 2018. He showed up at the nest and would not leave. FOBBV called the new male Shadow because he appeared so determined to stay in the nest, and the team initially believed he was one of Jackie’s siblings, also named Shadow. The eagle’s plumage indicated he was one year older than the other Shadow and not Jackie’s sibling, but the name stuck. 

Shadow continued to hold his ground and Mr. B gave up and eventually left. Jackie then accepted Shadow as her new mate.

Wildlife cameras documented Jackie and Shadow’s life together, offering viewers a direct look into the brutality and beauty of nature. The pair successfully raised chicks in 2019 (Cookie and Simba) and 2022 (Spirit). The pair’s eggs failed to hatch in 2023 and 2024. In 2025, Jackie laid three eggs that all hatched in early March. However, a strong snowstorm dumped up to two feet of snow and battered the nest with strong wind and only two of the chicks (Sunny and Gizmo) survived.  

In January, Jackie laid two eggs in the nest, but ravens destroyed them. She later laid two more eggs that hatched in April and named Luna and Sandy. The name Sandy is in honor of FOBBV’s former executive director Sandy Steers who died from cancer in February. 

an adult baled eagle with two eaglets
Jackie, Luna, and Sandy on their nest in May 2026. Image: Friends of Big Bear Valley.

Jackie’s injury and death

On July 17, Jackie was found injured on the ground near Dana Point Park, California. Cell phone video from a witness confirmed that she had an altercation with two other subadult eagles. She successfully fended off the other eagles by turning over and using her talons, but could not fly far away. 

She was transferred to the Ojai Raptor Center, where she was diagnosed with severe anemia. Her anemia worsened during the first week of August, the Ojai Raptor Center said that she was in unstable condition on August 9. Her packed cell volume (PCV) fell below percent, before rising to nine percent.  

On July 17, Jackie was found injured on the ground near Dana Point Park, California. Cell phone video from a witness confirmed that she had an altercation with two other subadult eagles. She successfully fended off the other eagles by turning over and using her talons, but could not fly far away. 

She was transferred to the Ojai Raptor Center for care, where she was diagnosed with severe anemia. Her anemia worsened during the first week of August, the Ojai Raptor Center said that she was in unstable condition on August 9. Her packed cell volume (PCV) fell below percent, before rising to nine percent. 

Jackie died early in the morning on August 10. The necropsy did not reveal a single cause of death, and instead pointed to several factors including severe anemia, blood clots in her wing and one kidney, and liver and lung abnormalities.

Jackie’s resilience inspired millions of people around the world. To honor her memory, FOBBV accepts donations to support its conservation efforts in the area.  Supporters can also donate to Ojai Raptor Center’s Bald Eagle Recovery Campaign. 

The post Jackie the bald eagle’s final cause of death revealed appeared first on Popular Science.

When ‘T. rex’ died, a new giant fungus named ‘D-rex’ took over

14 October 2026 at 19:34

It’s a fungi-filled world and we are just living in it. There are roughly 150,000 to 157,000 known species of fungi, and now there is a new giant species to add to that tally. 

A team of scientists exploring the forests of Yunnan in southern China discovered the new fungus, which shows just how large these organisms can grow. The new species Dianjunus rex grows vertical fruiting bodies (the top part of the fungi that we usually see as a mushroom) that can grow as high as a foot (50 centimeters) and weigh close to five pounds (2.2 kilograms). 

This new fungus is the largest known species within the phylum Ascomycota, the largest known phylum of fungi with over 64,000 known species. The new fungus is described in a study recently published in the journal Frontiers in Fungal Biology.

“This remarkable species represents a new fungal family, Dianjunaceae, and provides a rare window into the evolution of extreme fungal body forms,” Indunil C. Senanayake, a study co-author and mycologist at the Germplasm Bank of Wild Species of the Kunming Institute of Botany in China, said in a statement. “The discovery illustrates how much fungus biodiversity remains to be discovered in East Asian forests.”

The scientists spotted the fungus during fieldwork in the temperate coniferous forests near Damaidi and Yipinglang and in a tropical rainforest near Nanbang in southern China. They noticed large whitish fruiting bodies (called stromata) coming out of some fallen wood that belonged to an unknown species of Ascomycete fungus. 

Stromata of Dianjunus rex in the field. (a, c, d, f) Stromata attached to host roots. (b, e, g, h) Stromata around host plant. (a) Collectors. (i) Total weight of largest bilobedstromata. Image: Song, Yan, Pérez-Moreno, Zhang, Yang, Xie, Su, Liu, Wang, Liu, Yang, Yang, Liu, Shi, Wan, Cheewangkoon, Dai, Senanayake and Yu
Stromata of Dianjunus rex in the field. (a, c, d, f) Stromata attached to host roots. (b, e, g, h) Stromata around host plant. (a) Collectors. (i) Total weight of largest bilobedstromata. Image: Song, Yan, Pérez-Moreno, Zhang, Yang, Xie, Su, Liu, Wang, Liu, Yang, Yang, Liu, Shi, Wan, Cheewangkoon, Dai, Senanayake and Yu

Ascomycetes don’t always sprout traditional mushrooms, but release their spores from tiny, sac-like structures inside or on the surface of such fruiting bodies instead. They typically grow on woody roots of Chinese cork oak trees.

The team collected the curious fruiting bodies, and grew spores back in the lab to study the fungus’ morphology and its genome. The genetic tests and a detailed study of its morphology revealed that the fungus is a new species, a new genus, and even a new family. 

They named it Dianjunus rex (which the team calls D-rex for short), for its regal size and the ancient Dian kingdom. This ancient civilization in Yunnan reached its height during the second and first centuries BCE.

The team also found a connection to dinosaurs beyond its nickname which sounds like T. rex. It appears that this fungi family arose around 65 million years ago, or only one million years after the Cretaceous-Paleogene mass extinction event. This most famous of Earth’s mass extinctions wiped out the dinosaurs and countless other animals and plants.

“This timing raises an intriguing possibility. After the mass extinction, forests experienced dramatic changes, including the sudden availability of large amounts of dead plant material,” added Senanayake. 

For fungi, this kind of environmental disruption may have created new ecological opportunities for it to fill.

As for its size, D-rex’ fruiting bodies grow about 20 to 30 centimeters taller than other Ascomycetes. The team thinks this size might help the wind disperse their spores better in dense forests. However, a large fruiting body like D-rex requires a lot of energy, so the strategy may have evolved if the ecological benefits outweighed the energy costs.

The team also believes that there are more fungi waiting to be discovered in subtropical China—we just need to keep looking. 

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Sled dogs have stubby legs for a reason

14 October 2026 at 16:00

They’re some of Earth’s most powerful athletes, traversing thousands of miles of rough terrain in sub-zero temperatures, through blinding snow, and biting winds. Sled dogs have been helping humans travel across the planet’s coldest regions for centuries, hauling supplies, people, and equipment across the snow and ice. In the process, this important role that goes above and beyond simply being “man’s best friend” could have a visible impact on their evolution.

Sled dogs may have evolved shorter legs to help them pull loads more efficiently. Currently working sled dogs and those that lived about 2,000 years ago have six percent shorter leg bones than similar species, according to a study published today in the journal iScience. These findings could help biologists trace the origins of sled dogs and understand more about how dog-powered transportation spread over the past 9,000 years. 

“Sled dogs have played an indispensable role in communities in the Arctic,” Mitya Kletzerman, a study co-author and an archeologist at the University of Haifa in Israel, said in a statement. “Without dogs, people couldn’t move as efficiently to hunt, relocate as conditions changed, or travel between communities to exchange knowledge and share new ideas. Understanding how the practice evolved could give us new insights into how people adapted to life in the Arctic.” 

As of now, our earliest archeological evidence associated with dog sledding comes from 9,000-year-old sled parts and dog remains uncovered in 2017 on Zhokhov Island (present-day Russia). Sledding equipment like this is rarely found in the archaeological record, so it has remained difficult to pinpoint when and where the practice first emerged or spread. 

Earlier studies have shown that work associated with humans can leave traces in an animal’s skeleton. Reindeer used for racing, carrying loads, and pulling have limb bone differences compared to those that do not pull. Kletzerman and her team were curious if sled dogs have also developed particular skeletal traits that have helped them adapt to all of the physical demands of pulling a sled. 

In the study, the team developed a biomechanical model to help them understand how a dog’s body handles the work of pulling a sled. The model showed that one effective way to pull a sled loaded with material is for a dog to lower its center of gravity. This increases the canine’s ability to generate pulling force.  

“When people or animals pull a load, it tends to tip them backward. A lower or more forward position of the center of mass counteracts this effect, allowing greater pulling force,” Kletzerman explained. 

They then tested whether modern sled dogs have skeletal proportions that can lower their center of mass. They analyzed bones in 60 different modern canids, including sled dogs, wolves, spitzes, and mongrels. They then compared the lengths of five leg bones. Three in the forelegs (the humerus, radius, and ulna) and two in the hind legs (femur and tibia).

After accounting for overall skeletal size, they found that sled dogs have relatively shorter radius, ulna, and tibia bones than their non-sled pulling counterparts. These bones measured about six percent shorter on average.  

“It’s unclear how this trait developed, but selective pressure may have preserved it, because it gave sled dogs an advantage over other dogs,” Kletzerman said. 

To see if this characteristic already existed in ancient dogs, the team analyzed 82 ancient dog bones and three skeletons. The three skeletons were from ritually buried dogs uncovered from three archaeological sites associated with ancestral Inuit populations in present-day Chukotka, Russia, and date to 2,000 to 500 years ago.  

Nearly 89 percent of the bones were consistent with the modern sled-dog pattern of shorter leg bones, as were all three ritually buried dogs. According to the team, this suggests that the skeletal pattern may be an effective way to identify that canine remains belonged to a sled dog, even when archaeological remains are incomplete or do not have any direct evidence of sled equipment. 

“Dogs have been working alongside humans for thousands of years, but we’re only beginning to understand how that partnership shaped them,” Kletzerman concluded.

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Rh<sup>3+</sup> stabilized in KRh@MFI catalyses regioselective hydroformylation

Nature, Published online: 14 October 2026; doi:10.1038/s41586-026-11136-9

DFT investigations combined with spectroscopic and catalytic studies of disrupted subnanometric Rh2O3 clusters show that Rh+ centres in a zeolite-based catalyst are blocked with N-containing molecules, whereas Rh3+ sites are stabilized, allowing hydroformylation reactions with enhanced regioselectivity and efficiency.

Sexual dimorphism in epidermal stem cell dynamics

Nature, Published online: 14 October 2026; doi:10.1038/s41586-026-11159-2

Long-term live imaging of adult mouse ear skin reveals sex-specific differences in the clonal dynamics of epidermal stem cells and transit-amplifying cells during homeostasis.

Educational intervention can rewire village social networks

Nature, Published online: 14 October 2026; doi:10.1038/s41586-026-11154-7

A randomized controlled trial involving a health-education intervention in rural villages in Honduras shows that the intervention changed social network connections, including not only health-related connections but also friendships and financial ties.

How to watch Churchill’s famous polar bears live

13 October 2026 at 19:01

The internet’s favorite Fat Bears in Alaska are not appearing on wildlife cameras quite as much these days. The salmon has been eaten, the Fat Bear Week crown has been won, and it’s time to survive the winter ahead. However,  some other bears from the great white north are getting their close-up.

Explore.org and Polar Bears International run eight different livestreams from Churchill, Manitoba, Canada. Known as the polar bear capital of the world, Churchill’s Wapusk National Park is home to one of the world’s largest concentrations of polar bear (Ursus maritimus) maternity dens. During October and November, viewers can watch bear families wait for sea ice to form. 

Twenty populations of polar bears live in the Arctic. The population living along the Western Hudson Bay is one of the most comprehensively studied and best known. It is part of Canada’s “Seasonal Ice Ecoregion.” In this area of the Arctic, the sea ice completely melts in the summer, typically in July. While the bears may remain sporadically active on land, in the summer, they generally create day beds or curl up in the bush to rest. The pregnant females will often settle in or near their dens for several months to rest where it is cooler and with less mosquitoes. Many of these dens were first excavated by bears generations ago.

In the fall, all of the bears except the pregnant female will increase their activity and move closer to the coast. Here, the bears will hunt for seals once the bay freezes over again. From early October onward, they will gather on the tundra along the shores of Hudson Bay, waiting for ice to form. As soon as the first coastal ice is thick enough to support their weight, they will head out to find seals. They may continue to trek back and forth between ice and land at first, but they primarily head out onto the bay until it begins to thin and they ashore again in the summer.

These cameras are one way for scientists and the public to aid in real scientific research. In December 2025, scientists here confirmed that a wild female polar bear adopted a cub that was not her own. This rare behavior was captured on cameras during the polar bear’s annual migration along Western Hudson Bay. 

The mother bear (designated as bear X33991) was first spotted in spring 2025, when she came out of her maternity den with one tagged cub. When scientists saw her again in the fall, she had two cubs. One cub had a tag and one did not, indicating that the untagged cub was not hers. The survival rate for a polar bear cub into adulthood is about 50 percent, so only time will tell how this blended family will do. 

Viewers can also take a virtual ride on the Tundra Buggy Lodge from two different angles. The lodge is made of tundra buggies that are linked together like a train. This moving hotel includes staff quarters, a dining area, a supply cart, and two carts for guests.

By night, viewers can also take in another of the north’s natural wonders with the aurora borealis cam. The northern lights livecam is on top of the Churchill Northern Studies Center and located directly underneath the aurora oval. This spot is considered one of the best places to watch the aurora dance across the night sky. The aurora season is only just beginning, with late winter and early spring being the best times to tune into this camera.

And if birds are more your thing, a raven cam is streaming from Cape Churchill Wapusk National Park. The resident ravens selected the topside of a radar reflector attached to the Cape Churchill observation tower for their nest. This “cabin in the sky” has also been home to numerous biologists researching the local wildlife since the 1970s. This camera will be switched off at night to preserve power.

The organizations also provide highlight reels to help viewers catch up on what to watch for this winter. Happy polar bear season!

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Monarch butterfly saved after landing in refried beans

13 October 2026 at 16:06

A migrating monarch butterfly (Danaus plexippus) recently brought into Sweetbriar Nature Center in Smithtown on New York’s Long Island came with a unique backstory. The male butterfly flew into a nearby house and landed on a pot of refried beans. The man living there took the butterfly out of the pan, but by morning the butterfly still could not fly. There was only one thing left to do for the injured insect—bring him to the professionals.

“Butterflies are incredibly delicate, and even handling them can cause additional damage or leave them unable to fly,” Janine Bendicksen, Sweetbriar Nature Center’s Director of Wildlife Rehabilitation, tells Popular Science. “That makes butterfly rehabilitation especially challenging—we have to be extremely careful with every step.”

The team got to work on fixing this unusual patient. They started by checking the butterfly for a parasite called OE (Ophryocystis elektroscirrha) that can live on monarchs. If the insect is parasite-free, the team can then assess the injuries and determine whether rehabilitation is possible. Butterflies are very delicate, and just handling them can cause additional damage.

“In cases where a monarch has lost part of a wing, we may be able to transplant a portion of a donor wing,” says Bendicksen. “When the circumstances are right, we can carefully attach the donor wing to the injured butterfly.”

The team gently sprayed the butterfly’s wings with water several times to remove the bean residue that prevented him from flying. Then, a challenge arose. How do you remove the greasy residue from such delicate wings? The solution came from a common powdery substance found in kitchen pantries—cornstarch.

“We use starch regularly in wildlife rehabilitation to help dry out materials, and we had also previously used starch when replacing a wing on another monarch,” Bendicksen explains. “Because we already knew it was safe and effective in that context, we felt it was a good option for this particular situation. We were looking for something that would help remove the remaining moisture and residue without causing additional damage to the delicate wings.”

The cornstarch trick worked. The monarch was able to fly again. The team gently transported him outside and he took to the skies. Monarchs are currently on their way to the overwintering grounds in the forested mountains of Central Mexico. Their migrations are multigenerational, with roughly four generations of monarch butterflies emerging throughout the year. This butterfly may have been in the third generation (lays eggs in the north, but does not migrate) of the fourth generation that treks south. 

“It’s not often that we are called upon to rehabilitate a butterfly,” Bendicksen says. “Most butterflies have relatively short lifespans, but when we receive a monarch in the fall—especially one that will travel thousands of miles on its migration to Mexico—we do everything we can to give it the best possible chance.”

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Rocky the pumpkin wins ‘Superbowl of Pumpkin Weigh Offs’ at 2,389 pounds

12 October 2026 at 20:54

For the fifth time, pumpkin legend Travis Gienger won the Safeway World Championship Pumpkin Weigh Off today in Half Moon Bay, California. The gigantic gourd named Rocky weighed 2,389 pounds. It could be baked into approximately 1,194 pumpkin pies, and weighs about the same as an American bison (Bison bison) or a 2015 Chevy Spark.

The biggest gourd from this event tipped the scales 2,749 pounds and was grown by Gienger in 2023. On October 10, a new world record was set at the Southern New England Giant Pumpkin Growers Weigh-Off. Ron Wallace of Greene, Rhode Island’s pumpkin weighed 3,156 pounds, beating the previous record-holder by about 300 pounds.

As champion, Geigner will earn $9 per pound in prize money, so $21,900 total. He also will receive a Pumpkin King Champion Ring, the Mel Mello Sr. Grand Champion Growers Jacket, and other honors.

The 53rd annual event also featured a special appearance and carving by legendary pumpkin carver and farmer Mike Valladao. Affectionately called the “Picasso of Pumpkin Carvers,” the gourd artist commemorated his 40 years at the Half Moon Bay Art & Pumpkin Festival.

a carved pumpkin
The pumpkin that Mike Vallado carved during the festivities. Image: Safeway World Championship Pumpkin Weigh Off via Facebook.

The event began in 1974 as a friendly challenge between Half Moon Bay, California, and Circleville, Ohio, to see who could grow the biggest pumpkin. Half Moon Bay won that first showdown with a pumpkin weighing only 132 pounds. Today’s mega gourds can weigh more than 20 times as much. The event has also become an annual pilgrimage for the pumpkin growers who spend months nurturing their enormous Atlantic giants (Cucurbita maxima). These jumbo gourds sometimes gain dozens of pounds in a single day during peak growing season (August through September).

The event is an officially sanctioned Great Pumpkin Commonwealth competition, with weighing and inspection officiated by the GPC and San Mateo County Department of Agriculture Office of Weights and Measures.

Related Pumpkin Stories

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Bee stingers work like saws to pump venom  

12 October 2026 at 20:00

It’s one of nature’s seemingly magical tricks. A honey bee (Apis mellifera) stings a victim, and the stinger will still pump venom into a wound even after it has fully detached from the bee’s body. Thanks to some high-speed video, we may finally know the secrets behind this sting. 

A team in Australia found that the tiny 2 millimeter (or only 0.08 inch) stinger of a honey bee works like a double-piston micro-pump. It pumps in two different directions and can deliver a continuous flow of venom. The findings are described in a study published today in the journal PNAS.

“We’ve known since as early as 1910 that the venom sac of a honey bee stinger empties into a chamber with little pumping elements called valves, but until now we didn’t know exactly how they work,” Fiorella Ramirez-Esquivel, a study co-author and entomologist at Macquarie University, said in a statement. “If you’ve ever been stung by a bee, you’ll know it’s a very painful process, but now we’ve been able to identify all the working parts packed into the tiny stinger.”

In bees, autotomy is when a worker bee thrusts its stinger into a target and then leaves the stinger behind. The stinger then continues to penetrate into the target tissue and inject venom all on its own. 

To better understand how autotomy works, the team from Macquarie and the University of New South Wales had bees sting a clear gel that mimics human skin, while taking high-speed video. They saw that the tiny stinger itself contains several different components including one venom sac and a pumping chamber, muscles, and nerves. The stinger also has two sharp, pointed lancets. These lancets slide backwards and forwards on a system of rails (called the olistheter), similar to a reciprocating saw. These saw-like lancets are what pushes the stinger deeper into the skin and also pumps the venom.

Each of the two long lancets has a valve attached to it that sits inside of the pumping chamber. The team found that these valves change shape to form a seal during the downstroke. They then collapse during the upstroke, creating pressure for pumping while minimizing backflow when refilling.

“Finally, and perhaps most dramatically, as the valves meet in the middle of the stroke, they change shape again to push past each other,” said Ramirez-Esquivel. “This is a remarkable strategy to pump fluid since maintaining a seal is vital to effectively transmit pressure. The unique geometry of the valves is the key; they act as collapsible pistons and—by pumping in opposite directions—they’re able to deliver a continuous flow of venom.”

The team continued to explore the mechanics and flow of the stinger with microCT scans. They then used these scans to 3D print a small robot of the bulb chamber and lancets. The tiny bee-bot confirmed these key features of the pumping cycle.

“The double piston design adds complexity but it’s the key to the stinger being able to deliver venom continuously in a compact, autonomous unit,” said Dr Ramirez-Esquivel.

Understanding this mechanism could inspire designs for new micropumps to deliver medicine to human patients in a less invasive way.

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