Bonus: What On Earth's Earth Day special

Chimpanzees are being forced to eat bat feces, and the viruses in itResearchers in Uganda have noticed a new behaviour in the wild chimps they study. The apes are browsing on bat guano, apparently to access the nutrients it contains, as their normal source for these nutrients has been destroyed by humans. Since bats are carriers of a range of diseases, from ebola to coronaviruses, this may be a new way these diseases could spread. The study was published in Communications Biology. Dr Tony Goldberg, a professor of epidemiology at the school of veterinary medicine at the University of Wisconsin-Madison, was part of the team.Controversial methods are working to buy Canada’s caribou some timeWoodland caribou have been in steady decline for decades, as logging, oil and gas exploration and other disturbances compromise their western mountain habitat. Steady progress has been made to restore habitat in order to save these caribou, but since these forests will take half a century to regrow, conservationists are trying a variety of interim actions to buy the caribou some time. A new study led by Clayton Lamb from the University of British Columbia Okanagan found that these methods, including direct feeding, maternal penning, and, controversially, culling predatory wolves, have helped caribou recover to some extent, but restoration of their habitat will be necessary for full recovery. The research was published in the journal Ecological Applications.Giant ancient Pacific salmon had tusks sticking out of its faceMillions of years ago, enormous three metre-long salmon inhabited the seas of the Pacific coast. Named Oncorhynchus rastrosus, this ancient giant was first described in the 1970s as having long front fangs, which led to it being known colloquially as a “saber-toothed salmon.” But a new study published in PLOS ONE sets the record straight: the teeth actually protruded out to the sides from the fish’s upper jaw, as tusks do. Lead study author and Philadelphia College of Osteopathic Medicine professor Kerin Claeson says despite their menacing look, the salmon did not hunt with these tusks, since these strange fish were filter feeders.The Gulf oil spill may have had ecological impacts we haven’t seen yetFourteen years ago an explosion destroyed the Deepwater Horizon oil rig and kicked off the largest oil spill in history. While commercial fisheries have largely recovered from the disaster, there are signs that rarer and more vulnerable species might have been devastated. Prosanta Chakrabarty from Louisiana State University surveyed deep sea fish catalogued in museum collections around the world and found that out of 78 endemic species found only in the Gulf, 29 of them haven’t been spotted in the years since the spill. The research was published in the Biodiversity Data Journal.Primordial black holes may be the solution the problem of missing dark matterThe hunt for exotic black holes that Stephen Hawking first predicted back in the 1970s is now well underway. Primordial black holes behave just like any other black hole, but they would have  formed in the early universe and could  be any size. Many scientists are particularly interested in the primordial black holes that are the size of an atom and have the mass of an asteroid because they suspect they could be the answer for the missing dark matter in our universe. 

The climate is changing. So are we. On What On Earth, you’ll explore a world of solutions with host Laura Lynch and our team of journalists. In 1970, 20 million people showed up to fight for the environment on the first Earth Day. More than five decades later, is it time for this much tamer global event to return to its radical roots? OG organizer Denis Hayes recounts how – amidst other counterculture movements at the time – his team persuaded roughly one in ten Americans to take to the streets. As he approaches 80, Denis offers his singular piece of advice to the next generation of climate leaders. Then, environmental warriors Maria Blancas and Axcelle Campana share ideas on what a reinspired Earth Day could look like – including making it a public holiday.More episodes of What On Earth are available at: https://link.chtbl.com/5zF03qcmWe love to hear from our listeners and regularly feature them on the show. Have a question or idea? Email [email protected]

This researcher wants a new particle accelerator to use before she’s deadPhysicists exploring the nature of reality need ever more capable particle colliders, so they’re exploring a successor to the Large Hadron Collider in Europe. But that new machine is at least decades away. Tova Holmes, an assistant professor at the University of Tennessee, Knoxville, is one of the physicists calling for a different kind of collider that can come online before the end of her career – or her life. This device would use a particle not typically used in particle accelerators: the muon.Is venting the best way to deal with anger? The scientist says chill out.It turns out that acting out your anger might not be the best way to get rid of it. Sophie Kjaervik, a researcher at Virginia Commonwealth University in Richmond, Va., analyzed 154 studies of the different ways to deal with anger. Her results, published in the journal Clinical Psychology Review, suggest that techniques that reduce your heart rate and calm your mind are more effective than blowing off steam.High intensity wildfires may release toxic forms of metalsWildfire smoke might be more dangerous than you think. A recent study in the journal Nature Communications found that when wildfires pass over soils or rocks rich in a normally harmless metal called chromium, it is transformed into a toxic form. The hotter and more intense the wildfire is, the more of this metal becomes toxic. Scott Fendorf, an Earth system science professor at Stanford University, said this study shows we should factor in the type of geology wildfires pass over to provide more targeted air quality warnings about smoke risks. AI might help solve the problem of runaway conspiracy theoriesConspiracy theories seem to have multiplied in the internet era and so far, we haven’t had much luck in debunking these beliefs. The preliminary findings of a new study on PsyArXiv, a site for psychology studies that have yet to be peer-reviewed, suggests that artificial intelligence may have more success. Thomas Costello, a postdoctoral psychology researcher at MIT was the lead author on this study, and said their findings can provide a window into how to better debunk conspiracy beliefs. An Indigenous ecologist on why we need to stop and listen to save the planetEarth day is April 22. And Earth is not in great shape to celebrate the day. Overheated, overpopulated, overexploited – we’re not being particularly careful with our planet. We talk to Indigenous ecologist Jennifer Grenz, of the University of British Columbia, about her new book, which is part memoir, part prescription for the medicine our planet needs – a compound of science and traditional wisdom. Her book is Medicine Wheel for the Planet: A journey toward personal and ecological healing.

Old canned salmon provides a record of parasite infectionTo study marine ecosystems from the past, scientists picked through canned salmon dating back more than four decades to measure levels of parasites in the fish. Natalie Mastick, a postdoctoral researcher in marine ecology at Yale University, said she found the parasite load in two species of salmon increased in their samples between 1979 - 2021. She says this suggests their ecosystems provided more of the hosts the parasites needed, including marine mammals, which could reflect an increasingly healthy ecosystem. Their study is in the journal Ecology and Evolution. Mars has more influence on Earth than non-astrologers might have thoughtMars is, on average, about 225 million km from Earth, which would suggest that it has little impact on our planet. Which is true, but as they say a little goes a long way. In a recent study in Nature Communications, researchers studying the history of deep ocean currents found a surprising 2.4-million-year cycle where giant whirlpools form on the ocean floor, linked to cycles in the interactions of Mars and Earth orbiting the Sun. The team, including geophysicist Dietmar Müller from the University of Sydney, say this may act as a backup system to mix the oceans as the Earth warms.Medieval English silver pennies travelled a long wayStarting in the middle of the 7th century, economic development in medieval England was spurred by the increasing use of handy silver coins that greased the wheels of trade. To date, 7000 of these silver coins have been found that date to the period between the years 660 and 750 AD, but the source of the silver has been mysterious. Using modern technology, researchers from the University of Cambridge, including historian Rory Naismith,  have traced the silver right across the continent to its Byzantine source. In their study in the journal Antiquity, the researchers suggest the silver was brought to Europe a hundred years earlier in the form of silver objects, which were melted down and struck as coins in order to put more money into circulation.Bonobos are not as nice as their reputation suggestsBonobos are the lesser-known cousin of chimpanzees, and have a reputation for being the more peaceful ape. But a new study published in Current Biology reveals a dark side of bonobos. Anthropologist Maud Mouginot observed the behaviour of bonobos and chimpanzees in their dense tropical forest habitats in the Democratic Republic of Congo and Tanzania. She was shocked to find out that male bonobos were twice as likely to be aggressive toward other males than chimpanzees. She said this suggests that we need to have a more nuanced view of aggression within and across primate species, including humans. COVID infections are causing brain inflammation, drops in IQ, and years of brain agingFor many people COVID was more than a respiratory disease. We’re learning now just what kind of impact an infection can have on the brain. It can affect cognition – leading to the famous brain fog – and even shrink and prematurely age the brain. One of the researchers studying these effects is Dr. Ziyad Al-Aly, he has found COVID patients suffering from brain fog, confusion, tingling, mini strokes, and even seizure disorders.Listener Question – The eclipse and the moon’s temperature.A listener posting as Jeff on X writes: “How hot did the side of the moon that faced the sun get during the eclipse?”  We get the answer from Nikhil Arora, an astrophysicist from Queen’s University in Kingston.

Seeing a black hole’s magnetic personalityScientists using the Event Horizon Telescope have produced a new image of the supermassive black hole at the centre of our galaxy. And this image is a little different: it captures the powerful magnetic fields that are acting as the cosmic cutlery feeding mass into the singularity. Avery Broderick is part of the Event Horizon Telescope team, he’s also a professor at the University of Waterloo’s Department of Physics and Astronomy, and associate faculty at the Perimeter Institute for theoretical physics.Decoding how chickadees maintain a mental map of their food cachesChickadees have an uncanny ability to recall thousands of secret stashes of food with a centimetre-scale precision. Salmaan Chettih, a postdoctoral researcher in neuroscience at Columbia University, investigated how chickadees encode their internal treasure maps. In his study in the journal Cell, he found the chickadee brains produce a unique pattern of activity — akin to a neural “barcode” — that marks the X on its mental treasure map. Italians don’t just speak more with their hands, they speak differentlyResearchers comparing Swedish speakers with Italian speakers have found that the gestures they commonly use to accompany spoken language are quite different in kind. Lund University scientists Maria Graziano and Marianne Gullberg recorded the hand gestures study participants used when describing a children’s cartoon to their friends. According to the results published in a Frontiers in Communication journal, Swedish speakers used gestures that concretely represented the subjects of their speech, while Italian speakers used abstract gestures more related to emphasis. What came first, the drumstick or the omelette?New archaeological work along the famous Silk Road trade route between Asia and Europe has added to the picture of how the chicken was brought from its southeast Asian homeland to the rest of Eurasia. An international team of researchers, including archaeobotanist Robert Spengler, analyzed tiny eggshell fragments from the soil of multiple sites in Central Asia. Their findings, published in Nature Communications, suggest that the motivation for domesticating the fowl was not the chicken, but their eggs. LED lighting is bright, efficient, and perhaps a problemThe global transition to LED lighting seems to be having some concerning impacts on the natural world and human health. These energy efficient artificial lights produce different spectra than older incandescent technology, or the natural light of the Sun that life on Earth evolved with over billions of years. LED lighting is brighter, bluer, and more widely used than incandescent lighting. Glen Jeffery, a professor of neuroscience from University College London, said that as a result, we may be paying the price with our health due to being oversaturated with blue light and starved of red and infrared light. In a new study in the Journal of Biophotonics, he found that exposing people to red and infrared light lowered their blood glucose levels by “charging up” our cells’ energy production.Artificial light at night is also having “a profound impact” on our environment in how it affects plants and wildlife and the ecosystems they’re in, according to Kevin Gaston, a professor of biodiversity and conservation at the University of Exeter. He said for nocturnal animals, the challenge they face from light pollution is the equivalent to humans losing daylight during the daytime. His review was published in the Annual Review of Environment and Resources. 

Archaeologists identify a medieval war-horse graveyard near Buckingham Palace We know knights in shining armor rode powerful horses, but remains of those horses are rare. Now, researchers studying equine remains from a site near Buckingham Palace have built a case, based on evidence from their bones, that these animals were likely used in jousting tournaments and battle. Archeologist Katherine Kanne says the bone analysis also revealed a complex, continent-crossing medieval horse trading network that supplied the British elites with sturdy stallions. This paper was published in Science Advances.In an ice-free Arctic, Polar bears are dining on duck eggs — and gulls are taking advantageResearchers using drones to study ground-nesting birds in the Arctic have observed entire colonies being devastated by marauding polar bears who would normally be out on the ice hunting seals – except the ice isn’t there. What’s more, now they’re enabling a second predator – hungry gulls who raid the nests in the bears’ wake. Andrew Barnas made the observations of this “gull tornado” following around polar bears in East Bay Island in Nunavut. The research was published in the journal Ecology and Evolution.A NASA mission might have the tools to detect life on Europa from spaceNASA’s Europa Clipper mission, due to launch this fall, is set to explore the jewel of our solar system: Jupiter’s moon, Europa. The mission’s focus is to determine if the icy moon, thought to harbour an ocean with more water than all of the water on Earth, is amenable to life. However, postdoctoral researcher Fabian Klenner, now at the University of Washington, led a study published in the journal Science Advances that demonstrated how the spacecraft may be able to detect fragments of bacterial life in a single grain of ice ejected from the surface of the moon. Pollution is preventing pollinators from finding plants by scentOur polluted air is transforming floral scents so pollinators that spread their pollen can no longer recognize them. In a new study in the journal Science, researchers found that a certain compound in air pollution reacts with the flower’s scent molecules so pollinators — like the hummingbird hawk-moths that pollinate at night — fail to recognize them. Jeremy Chan, a postdoctoral researcher at the University of Naples, said the change in scent made the flowers smell “less fruity and less fresh.”An Australian Atlantis and underwater archeological remains in the Baltic During the last ice age sea levels were more than 100 metres lower than they are today, which means vast tracts of what are currently coastal seafloor were dry land. Geologists and archaeologists are searching for these lost landscapes to identify places prehistoric humans might have occupied. These included a country sized area of Australia that could have been home to half a million people. Archaeologist Kasih Norman and her colleagues published their study of this now-drowned landscape in Quaternary Science Reviews. Another example is an undersea wall off the coast of Northern Germany that preserves an underwater reindeer hunting ground, described in research led by Jacob Geersen, published in the journal PNAS.

How animals dealt with the ‘Anthropause’ during COVID lockdowns (1:04)During the COVID lockdowns human behaviour changed dramatically, and wildlife scientists were interested in how that in turn changed the behaviour of animals in urban, rural and wilderness ecosystems. In a massive study of camera trap images, a team from the University of British Columbia has built a somewhat surprising picture of how animals responded to a human lockdown. Cole Burton, Canada Research Chair in Terrestrial Mammal Conservation at the University of British Columbia, was part of the team and their research was published in Nature Ecology & EvolutionScientists helping maintain an essential ice road to a northern community (9:40)The only ground connection between the community of Délı̨nę in the NWT and the rest of the country is a winter ice road that crosses Great Bear Lake. But climate warming in the north is making the season for the road shorter, and the ice on the lake less stable. A team of scientists from Wilfrid Laurier University, led by Homa Kheyrollah Pour, are supplementing traditional knowledge about the ice with drones, sensors, satellites and radar to help the community maintain a safe connection with the world.Stars nudging the solar system’s planets leads to literal chaos (17:40)The orbits of the planets in our solar system are in a complex dance, orchestrated by the gravitational pull from the sun but influenced by their interactions with each other. Now, due the findings of a new study in The Astrophysical Journal Letters, that dance is a lot harder to predict. Nathan Kaib, from the Planetary Science Institute, said the chaos that stars passing by our solar system introduces to simulations deep into the past or far into the future make our planetary promenade predictions a lot less certain. A freaky fish, the gar, really is a living fossil because evolution has barely changed it (26:33)`The seven species of gar fish alive today are nearly indistinguishable from their prehistoric fossilised relatives that lived millions of years ago. Now in a new study in the journal Evolution, scientists describe why these “living fossils” have barely changed and why two lineages separated by 105-million years can hybridise. Chase Brownstein, a graduate student at Yale University, discovered the gar’s genome has changed less over time than any other species we know, a finding which could hold the key to fighting human diseases like cancer.Water, water, everywhere. But will we have enough to drink? (33:47)To mark world water day, Quirks & Quarks producer Amanda Buckiewicz is looking at the challenges we’re facing with our global freshwater resources. It’s one of Nature’s bounties, and vital to agriculture and healthy ecosystems. But climate change and overexploitation are creating a global water crisis as glaciers melt, snowpack becomes less predictable, rainfall patterns change, and we overdraw the global groundwater bank. We spoke with:Miina Porkka, associate professor from the University of Eastern Finland. Related paper published in the journal Nature.Christina Aragon, PhD student at Oregon State University. Related paper published in the journal Hydrology and Earth System Sciences.Katrina Moser, associate professor and chair of the department of Geography and Environment at Western University.Scott Jasechko, associate professor at the Bren School of Environmental Science and Management at the University of California, Santa Barbara. Related paper published in the journal Nature.

Why a detective is studying blood spatters in zero-gravityThere hasn’t been a murder on the International Space Station — yet. But Crime Scene Investigator Zack Kowalske has been studying how blood spatters in microgravity so that when someone does commit the first astro-cide, he’ll be able to use science to figure out whodunit. Kowalske sent a blood substitute for a ride on a parabolic microgravity flight to study how the absence of gravity changes how it moves, and discovered that surface tension takes over to shape how the blood splatters. The research was published in the journal Forensic Science International Reports.Lifting the fog to let starlight shine through at the cosmic dawnNot too long after the Big Bang, the universe went dark for many millions of years. Stars, black holes and galaxies began to form, but the universe was full of a cosmic fog in the form of light-absorbing hydrogen gas that blocked light from shining through. Hakim Atek, from the Paris Institute of Astrophysics led a group that used the James Webb Space Telescope to identify what cleared that fog: dwarf galaxies. In his new study in the journal Nature, Atek describes how young and tiny galaxies full of super-bright stars emitted enough radiation to burn through the fog and fill the universe with light. Do whales get hot flashes? They have menopauseWe don’t know if whales experience the same symptoms as human women, but in five known species of toothed whales, females do experience menopause. This is unusual as extended post-reproductive life is very rare in mammals — most of the time animals reproduce until the end of their lifespan. A new study led by Sam Ellis from the University of Exeter suggests that they have it for the same reason humans are thought to: because grandmothers are useful to have around. The research was published in the journal Nature.Bees can learn tasks that are more complicated than they can inventResearchers have laboriously taught bumblebees a complex, multi-step task that they never would have learned in nature, and found that once they learned it, other bumblebees could learn to do it from then. This suggests that they share with humans the ability to hold cultural knowledge that exceeds their own innovative capabilities. Behavioural scientist Alice Bridges was part of the team and the research was published in the journal Nature. Our planet’s circulatory system depends on animals eating, excreting and expiringDid you know our planet has a circulatory system? It moves vast amounts of nutrients over huge distances, processing them to extract energy and efficiently recycle them as well. It’s called animal life, and in a new book called Eat, Poop, Die: How Animals Make Our World, biologist Joe Roman explains how it works — and how restoring wild animal populations might be the best nature-based tool we have to beat the climate crisis.

Nature’s nurturing side — disabled primates thrive in the wild with community supportSurvival of the fittest for primates in the wild often includes them going out of their way to accommodate those with physical disabilities. In a study in the American Journal of Primatology, scientists reviewed 114 studies of a wide range of non-human primates that spanned more than nine decades. Brogan Stewart, a PhD candidate from Concordia was part of the team that found that more often than not, the physical disabilities arose as a result of human activities, and in the face of those pressures, primates show a remarkable resilience in how they care for those with malformations or impairments.Beetle larvae feeding on dino feathers left signs of that relationship trapped in amberBits left behind from a beetle larvae feasting on dinosaur feathers shed by a theropod became trapped in tree resin that preserved evidence of this relationship for 105 million years. The beetle larvae is related to a beetle that’s known to live in birds’ nests and feed on their feathers. Ricardo Perez de la Fuente, the senior author of the study in PNAS from Oxford University Museum of Natural History, said finding dinosaur feathers is a find in itself but to find evidence of two organisms in deep time interacting is incredibly rare. Jellyfish demonstrate how it’s possible to learn and remember even without a brainA jellyfish the size of a pinky nail can learn to spot and dodge obstacles using their visual system with 24 eyes but no centralized brain. By simulating their natural murky mangrove environment in a lab, scientists discovered how quickly the box jellyfish learned to maneuver around roots in their path. Jan Bielecki, a biologist at Kiel University, said their findings in the journal Current Biology suggest that learning is an integral function of neurons.Bottlenose dolphins sense their prey’s electrical fields through their whisker dimplesDolphins were once thought to be acoustic specialists due to their hearing ability and how they detect prey through their reflected pings using echo-location. But when their next meal is hiding in the sand, bottlenose dolphins also seem to be able to hone in on their prey by sensing their electrical fields. Tim Hüttner, a biologist at Nuremberg Zoo, said dolphins likely use echo-location to detect from afar and electroreception to close in on their prey. His research was published in the Journal of Experimental Biology.How documenting the disappearance of the great auk led to the discovery of extinctionBefore a fateful trip in 1858 when two biologists traveled to Iceland in search of the rare penguin-like great auk, the word “extinction” had never been used to describe a species that humans wiped out of existence. After being unable to locate any living great auks, John Wolley and Alfred Newton turned their attention to documenting the demise of this flightless bird. The new book, The Last of Its Kind: The Search for the Great Auk and the Discovery of Extinction, Icelandic anthropologist Gísli Pálsson explores the case that ushered in our modern understanding of extinction. Listener questionChris Corbett from North Sydney asks: If we see the star Betelgeuse, that’s 642 light years from Earth, going supernova, does that mean it might have already gone supernova? For the answer, we went to Jess McIvor, an astronomer at the University of British Columbia.

Speedy ocean predators change their skin colour to signal they’re going in for the kill (1:02)Marlin are predatory fish that can reach tremendous speeds in pursuit of food, making collisions between them potentially deadly. A new study has shown that the fish display bright and vivid skin colours to signal to other marlin when they’re attacking prey, so as to avoid butting heads. Alicia Burns and her team from the Science of Intelligence Cluster, Humboldt University used drones to capture video footage of the marlins’ hunting behaviour.The tiny genetic fluke that led humans — and other great apes — to lose our tails (9:15)Back when in our evolutionary history, a fragment of genetic material accidentally found itself in in a gene long been known to be important for the development of our entire back end. The result of this mutation, according to a study in the journal Nature, was that we and our great ape ancestors lost our tails. Itai Yanai, a cancer biologist from New York University Grossman Medical School, identified the mutation and found when they duplicated it in mice, they also lost their tails. A cannibal star shows signs of its last meal (18:06)Astronomers have identified a nearby white dwarf star with what they are calling a ‘scar’ of material visible on its surface. This was probably an asteroid flung towards the star, ripped apart by its gravity, and its rubble drawn onto the star’s surface by its powerful magnetic field. This is the first time such a phenomenon has been seen. This study was conducted by a team including astronomer John Landstreet, a professor emeritus from the Physics and Astronomy Department at Western University.Stone age craftsmen acted like engineers when selecting materials for their tools (26:32)A new study of what it takes to make efficient and effective stone tools, like the ones ancient humans were producing back in the Middle Stone Age, shows how discriminating they were in the materials they selected. Patrick Schmidt, an archaeologist from University of Tübingen, published a study in the journal PNAS about a model he developed to assess how well suited the raw materials were for the type of tools they were creating. Schmidt said their findings suggest that stone age craftsmen had an engineer’s understanding of the mechanical properties of the materials they used.Boreal forest on the move — the past, present, and potential future of the ‘lungs of the planet’ (35:39)The boreal forest has an important role in maintaining a healthy planet, by storing carbon, purifying the air and water, and helping to regulate the climate. Researchers are using novel ways to understand how the boreal forest has changed over time, to help predict how it can change in the future.Paleoecologist Sandra Brügger traced a detailed history of the forests in Eastern Canada over the past 850 years by studying trapped pollen found thousands of kilometers away in the Greenland ice sheet. The ice cores allowed the team to look at the shrinking and expansion of the forest since the Little Ice Age, and spot the effects of humans as they took over the landscape. The research was published in the journal Geophysical Research Letters.Then, by doing detailed analysis of trees along the Brooks mountain range in Alaska, a team of researchers including Colin Maher discovered a link between retreating sea ice and an expanding Boreal forest. When the sea ice disappears, the open water generates more snow, which not only blankets the landscape and protects the young seedlings, but it also helps the soil unlock more nutrients for the growing trees. The research was published in the journal Science.