Latest news with #BogongMoth
Yahoo
5 hours ago
- Science
- Yahoo
This Australian moth may be the 1st insect ever discovered to use stars for long-distance navigation
When you buy through links on our articles, Future and its syndication partners may earn a commission. Stand outside one spring night in southeastern Australia and you may be able to witness one of the biggest insect migrations in the world, as billions of brown Bogong moths (Agrotis infusa) flit across the sky. Each year in the spring, the moths migrate around 620 miles (1,000 kilometers) north to the Australian Alps, where they can avoid the heat by hiding in cool caves until the fall, when they return to their breeding grounds. While migration is not uncommon in insects, the Bogong moth's migration has been of particular interest to experts — how does a moth travel to a place it's never visited before? Researchers believe they now have the answer: stellar navigation. This would make the Bogong moth the first insect to use the stars for long-distance navigation as it makes its extended migratory journey. Stellar navigation has a long history for both humans and animals, from ancient Polynesians to migratory birds. Given the stars' dominance in the night sky, it's not surprising for experts to think that other animals, like insects, may also use these twinkling lights for navigating. "We knew from a previous study that the moths can use the geomagnetic field to navigate, but they only seemed to be able to do so in combination with visual landmarks, so we were thinking about what kind of landmarks these could be," explained Andrea Adden, a researcher at the Francis Crick Institute in the United Kingdom. "If you go to the Australian bush, where these moths live, and look around you at night, one of the most obvious visual landmarks is the Milky Way, which is always visible to some extent, independent of time of night and season," Adden said. "We know that daytime migratory insects use the sun, so testing the starry sky seemed an obvious thing to try." To test whether these moths are truly using the stars to navigate, the researchers captured several using a light-trap. This required the team to traverse into the dark, cold caves where the moths were resting during their migration, which, for some of the team, proved to be too challenging. According to Eric Warrant, a researcher at the University of Lund in Sweden and the leader of the project, "One of the most embarrassing [stories] was when Lena Nordlund from Swedish Radio (who was with us in Australia doing a documentary) asked why I always sent [the] youngsters in the cave and I always sat outside. I was forced to admit I was claustrophobic and was scared of going in — something that of course she included in the documentary." Though Warrant was not comfortable going into the caves, that didn't stop his collaborator, David Dreyer, also a researcher at the University of Lund, from challenging Warrant to a little competition to see who could catch the first Bogong moth of the migratory season. This competition lasted over a decade, with 20 different seasonal opportunities to compete. "[I] dominated this competition, [winning] 19 migratory seasons," Dreyer explained jokingly. "[My] 19 wins would remain unreported, until now. Justice at last." After capturing the moths, the team then placed them in a planetarium-like flight simulator, which included multiple projectors that could be programmed to give specific scenery. The simulator also blocked Earth's magnetic field, forcing the moths to try to navigate in the simulation by their eyesight alone. The researchers also attached electronic sensors to the moths to measure their brain activity. As Bogong moth brains are around the size of a grain of rice, adding the sensors was incredibly time-consuming. "Studying the neural basis of how these moths navigate reveals new processing mechanisms in the insect brain," Adden noted. "Even though human brains and insect brains are obviously very different, it often turns out that the computational principles are remarkably similar, so perhaps we can even learn something from moths that, one day, helps reveal something about the human brain." Once the moths were prepared, the researchers waited for evening in the outback, and then began to test the moths by recording their virtual flight paths in the simulator. "We continued this process until we had used all the prepared moths," Dreyer said. "The following morning was dedicated to data analysis. This routine continued until every moth from the previous catch had been tested — after which we would head out to catch a new batch." While studying the Bogong moths, the COVID-19 pandemic hit Australia, forcing a lockdown. For Adden, this meant being stuck out in the field. "A colleague and I were just wrapping up the field season in early 2020 when Australia entered its first Covid-19 lockdown, and the two of us were locked down at the field station for about a month," she said. "This wasn't as bad as it might seem — with no other humans in sight, we spent our days analyzing data, watching local wildlife and learning to sew." Adden even took the time to practice her astrophotography skills, taking photos of the very night sky her research subjects leveraged to navigate. After years of analysis, the researchers found that the Bogong moths fly in the seasonally appropriate direction (north or south) depending on the stars in the night sky, suggesting that they do in fact use the stars to guide them. "The stars are a very consistent cue. Even though the starry sky rotates throughout the night, the brightest part of the Milky Way is always in the South of the Southern celestial hemisphere," said Adden. "That makes it a very stable compass cue that is reliable not just across nights and seasons, but across centuries." From the moth's brain activity, the team also saw responses specific to certain rotations of the night sky in the flight simulator, and determined that their brains were the most active when they were "flying" in the right direction of their migration. While the Bogong moth is not the only insect to use the stars for guidance, it is the first to do so for long-distance journeys, scientists said. 'A previous study established that dung beetles use the stars to guide short-distance movements, but the beetles only travel a short distance (maybe 5-20 meters) as opposed to flying 1,000 km during a migration,' Ken Lohmann, a researcher at the University of North Carolina, Chapel Hill who was not involved in the study, told Studying how animals like moths navigate is not only fascinating, but can also help ensure the moth populations remain at a healthy level. "The Bogong moth population declined dramatically after the recent drought and 2020 bushfires," explained Adden. "Understanding how their migration works, and which cues they use to navigate, may help us protect these insects, which in turn helps the entire alpine ecosystem of which the moths are an integral part — e.g., as food for pygmy possums and all sorts of birds during the summer months." Part of that conservation work is looking at the role urbanization and, more specifically, light pollution plays in affecting the moths' migratory path. "Light pollution may well be a problem for Bogong moths during their migration,' Adden said. 'On their way from Southern Queensland to the Australian Alps, they pass several major cities, such as Canberra, which can be disorienting and trap the moths. In fact, this happened several years ago, when a cloud of moths briefly took over the Australian Parliament." While the Bogong moth shows the ingenuity of animals, for researchers and conservationists alike, understanding the animal navigation process as a whole is key to understanding their lifestyle, and therefore being able to protect them further. "A central lesson of animal navigation is that species almost always have multiple ways to guide themselves," said Lohmann. This study was published online today (June 18) in the journal Nature.
Washington Post
10 hours ago
- Science
- Washington Post
Meet the bug that uses the stars to navigate hundreds of miles
NEW YORK — An Australian moth follows the stars during its yearly migration , using the night sky as a guiding compass, according to a new study. When temperatures heat up, nocturnal Bogong moths fly about 620 miles (1,000 kilometers) to cool down in caves by the Australian Alps. They later return home to breed and die.
Yahoo
10 hours ago
- Science
- Yahoo
This Australian moth may be the 1st insect ever discovered to use stars for long-distance navigation
When you buy through links on our articles, Future and its syndication partners may earn a commission. Stand outside one spring night in southeastern Australia and you may be able to witness one of the biggest insect migrations in the world, as billions of brown Bogong moths (Agrotis infusa) flit across the sky. Each year in the spring, the moths migrate around 620 miles (1,000 kilometers) north to the Australian Alps, where they can avoid the heat by hiding in cool caves until the fall, when they return to their breeding grounds. While migration is not uncommon in insects, the Bogong moth's migration has been of particular interest to experts — how does a moth travel to a place it's never visited before? Researchers believe they now have the answer: stellar navigation. This would make the Bogong moth the first insect to use the stars for long-distance navigation as it makes its extended migratory journey. Stellar navigation has a long history for both humans and animals, from ancient Polynesians to migratory birds. Given the stars' dominance in the night sky, it's not surprising for experts to think that other animals, like insects, may also use these twinkling lights for navigating. "We knew from a previous study that the moths can use the geomagnetic field to navigate, but they only seemed to be able to do so in combination with visual landmarks, so we were thinking about what kind of landmarks these could be," explained Andrea Adden, a researcher at the Francis Crick Institute in the United Kingdom. "If you go to the Australian bush, where these moths live, and look around you at night, one of the most obvious visual landmarks is the Milky Way, which is always visible to some extent, independent of time of night and season," Adden said. "We know that daytime migratory insects use the sun, so testing the starry sky seemed an obvious thing to try." To test whether these moths are truly using the stars to navigate, the researchers captured several using a light-trap. This required the team to traverse into the dark, cold caves where the moths were resting during their migration, which, for some of the team, proved to be too challenging. According to Eric Warrant, a researcher at the University of Lund in Sweden and the leader of the project, "One of the most embarrassing [stories] was when Lena Nordlund from Swedish Radio (who was with us in Australia doing a documentary) asked why I always sent [the] youngsters in the cave and I always sat outside. I was forced to admit I was claustrophobic and was scared of going in — something that of course she included in the documentary." Though Warrant was not comfortable going into the caves, that didn't stop his collaborator, David Dreyer, also a researcher at the University of Lund, from challenging Warrant to a little competition to see who could catch the first Bogong moth of the migratory season. This competition lasted over a decade, with 20 different seasonal opportunities to compete. "[I] dominated this competition, [winning] 19 migratory seasons," Dreyer explained jokingly. "[My] 19 wins would remain unreported, until now. Justice at last." After capturing the moths, the team then placed them in a planetarium-like flight simulator, which included multiple projectors that could be programmed to give specific scenery. The simulator also blocked Earth's magnetic field, forcing the moths to try to navigate in the simulation by their eyesight alone. The researchers also attached electronic sensors to the moths to measure their brain activity. As Bogong moth brains are around the size of a grain of rice, adding the sensors was incredibly time-consuming. "Studying the neural basis of how these moths navigate reveals new processing mechanisms in the insect brain," Adden noted. "Even though human brains and insect brains are obviously very different, it often turns out that the computational principles are remarkably similar, so perhaps we can even learn something from moths that, one day, helps reveal something about the human brain." Once the moths were prepared, the researchers waited for evening in the outback, and then began to test the moths by recording their virtual flight paths in the simulator. "We continued this process until we had used all the prepared moths," Dreyer said. "The following morning was dedicated to data analysis. This routine continued until every moth from the previous catch had been tested — after which we would head out to catch a new batch." While studying the Bogong moths, the COVID-19 pandemic hit Australia, forcing a lockdown. For Adden, this meant being stuck out in the field. "A colleague and I were just wrapping up the field season in early 2020 when Australia entered its first Covid-19 lockdown, and the two of us were locked down at the field station for about a month," she said. "This wasn't as bad as it might seem — with no other humans in sight, we spent our days analyzing data, watching local wildlife and learning to sew." Adden even took the time to practice her astrophotography skills, taking photos of the very night sky her research subjects leveraged to navigate. After years of analysis, the researchers found that the Bogong moths fly in the seasonally appropriate direction (north or south) depending on the stars in the night sky, suggesting that they do in fact use the stars to guide them. "The stars are a very consistent cue. Even though the starry sky rotates throughout the night, the brightest part of the Milky Way is always in the South of the Southern celestial hemisphere," said Adden. "That makes it a very stable compass cue that is reliable not just across nights and seasons, but across centuries." From the moth's brain activity, the team also saw responses specific to certain rotations of the night sky in the flight simulator, and determined that their brains were the most active when they were "flying" in the right direction of their migration. While the Bogong moth is not the only insect to use the stars for guidance, it is the first to do so for long-distance journeys, scientists said. 'A previous study established that dung beetles use the stars to guide short-distance movements, but the beetles only travel a short distance (maybe 5-20 meters) as opposed to flying 1,000 km during a migration,' Ken Lohmann, a researcher at the University of North Carolina, Chapel Hill who was not involved in the study, told Studying how animals like moths navigate is not only fascinating, but can also help ensure the moth populations remain at a healthy level. "The Bogong moth population declined dramatically after the recent drought and 2020 bushfires," explained Adden. "Understanding how their migration works, and which cues they use to navigate, may help us protect these insects, which in turn helps the entire alpine ecosystem of which the moths are an integral part — e.g., as food for pygmy possums and all sorts of birds during the summer months." Part of that conservation work is looking at the role urbanization and, more specifically, light pollution plays in affecting the moths' migratory path. "Light pollution may well be a problem for Bogong moths during their migration,' Adden said. 'On their way from Southern Queensland to the Australian Alps, they pass several major cities, such as Canberra, which can be disorienting and trap the moths. In fact, this happened several years ago, when a cloud of moths briefly took over the Australian Parliament." While the Bogong moth shows the ingenuity of animals, for researchers and conservationists alike, understanding the animal navigation process as a whole is key to understanding their lifestyle, and therefore being able to protect them further. "A central lesson of animal navigation is that species almost always have multiple ways to guide themselves," said Lohmann. This study was published online today (June 18) in the journal Nature.
Yahoo
18 hours ago
- Science
- Yahoo
Migrating moths can read the stars
Imagine traveling more than 600 miles from the only home you've ever known, to a mountain ridge you've never been to. It's nighttime, completely dark, and you don't have a map, GPS, compass, or sextant to guide you. Could you make it? If you were a Bogong moth (Agrotis infusa), this epic journey would be a standard part of your life cycle. In fact, you'd do it twice in one year. The endangered, drab beige, nocturnal insects fly across Australia's southeastern corner from points inland to caves nestled in the Australian Alps, near the coast, where they retreat to escape the summer heat. During spring migration, recently hatched and newly mature moths move from the breeding grounds they were born in, to the distant, unfamiliar caverns. In autumn, after months of dormancy spent clustered on cave walls, they reverse course. Despite having brains smaller than a grain of rice and teeny eyes to match, they manage to hit their geographic targets en masse. A new study offers insight into how. Bogong moths follow the stars, using the night sky as a navigational aid, according to a study published June 18 in the journal Nature. In addition to being guided by Earth's magnetic field, like many migratory species, the stars provide the insects with a backup, 'stellar compass' to light the way. Birds and humans are known to navigate via the stars. A 2024 study even suggests dung beetles rely on the Milky Way to help them stay on a straight course over short distances. But the new findings represent the first time an invertebrate has been shown to use the sky to direct a long distance migration, says Kenneth Lohmann, a biologist at the University of North Carolina who wasn't involved in this study. Lohmann researches animal ocean migrants, like sea turtles and salmon, and authored a viewpoint article published alongside the new study. 'I liked [the research] enough that I offered to write a perspective,' he tells Popular Science. 'I found it remarkable that an insect with a very tiny brain was capable of achieving these astounding navigational tasks. …The results strongly suggest that the moths inherit the ability to guide themselves using the stars.' For a human, the moth's journey would be 'the equivalent of circumnavigating the Earth twice, without any instruments apart from your own senses,' Eric Warrant, study co-author and a neurobiologist at Lund University in Sweden, tells Popular Science. That moths can manage such precise travel 'puts me in awe,' he says. The new paper builds on research from 2018, where Warrant and many of the same colleagues found that moths rely on Earth's magnetic field to guide them, in combination with some unknown visual cue. Now we know what the clue is: stars. [ Related: Why do birds migrate? Scientists have a few major theories. ] To parse the importance of the sky for moth wayfinding, the team started by shaving a small bare patch on dozens of captured insects' thoraxes, just between the wings. 'You have to remove the scales, because moths are very hairy creatures,' says David Dreyer, lead study author and also a neurobiologist at Lund University. Then, Dreyer and his team glued tungsten wires in place, and tethered each moth (one at a time) to a small scaffolding set-up that recorded the insects' attempted flight direction and intensity five times per second. In an initial control experiment, they collected migrating moths near the cave site in autumn and placed each tethered moth inside a clear plastic enclosure on top of a hill outside, with the night sky in full view and access to Earth's magnetic field. As expected, the moths directed their flight north-northwest– aiming towards their breeding grounds, even when trapped unnaturally beneath scaffolding. In subsequent experiments, repeated in spring and fall, they moved their flight simulator indoors, to a lab specially equipped with a device to block out magnetic fields. There, the team put over 100 moths to the test. First, they recorded migrating moths' flight directions with no coherent magnetic guide and no visual stimulation, underneath a black felt tent. The moths were totally disoriented, flying every which way at random. Then, they fashioned the felt tent into something similar to a miniature moth-sized planetarium. The scientists added a projection screen at the top and showed a realistic version of what the moonless night sky outside would look like at the time of the experiment. When given the sky, but still deprived of magnetic information, the moths overwhelmingly flew in the correct, migratory direction according to the season: north-northwest in fall, southwards in spring. If the sky projection rotated, the moths shifted their trajectory to match. 'Moth after moth after moth that we put under the sky, when we knew that there was no other cue they could be using… flew consistently in the direction that they needed to fly in at that time of year to reach their destination,' says Warrant. 'That was quite amazing.' Of course, there were exceptions. Some moths seemed 'completely freaked out' by the whole set-up, Warrant explains. But the mean trajectory of all the insects'' many flights was significantly aligned with the theoretical migration path. In additional tests, the moths were shown a projection of randomized, mixed up stars, not corresponding to the actual sky. Again, they became disoriented, firming up the hypothesis that the cosmos offer a key visual signal. Finally, it was time for insect neurosurgery. The researchers inserted extremely thin pulled glass and silver wire electrodes into neurons in three areas of the 28 different moths' brains. 'It's like pushing a thin pin into your arm,' says Warrant of getting the improbably small electrode in contact with the axon of a single moth neuron. The team initially restrained the moths while showing them a sky projection and recorded the subsequent neural activity. When the sky indicated the moths were oriented in the proper migratory direction, electrical activity in neural regions related to vision, navigation, and steering all peaked. In another simulation, the moths were shown an artificial cue meant to mimic the bar shape of the bright milky way viewed from the Southern Hemisphere. This cue, alone, seemed to be enough to stimulate a similar brain response. 'The experiments were carefully controlled and well thought out,' says Lohmann. 'I thought they yielded very clear results,' he adds– that the stars are sufficient to help Bogong moths navigate migration. Most migratory animals seem to depend on several sensory cues to aid in their journeys, Lohmann notes. 'It's very common for animals to have more than one way to maintain a consistent heading,' he says. For instance, the sea turtles he studies use Earth's magnetic fields, but also the direction of waves and potentially the sun. The moths are no exception. When you're doing high stakes, long distance travel, having a secondary GPS makes sense. Clouds can obscure the sky, while solar storms and terrestrial anomalies (like a large iron deposit) can distort the planet's magnetic field. 'It's a great idea to have a backup compass when one stuffs up for whatever reason,' says Warrant. 'Nature is way more clever than we are, so evolving two compasses like this just makes everything much more robust.' Yet with two compasses in hand, confusion and questions still remain. It's unclear how the navigational neural circuits work together, if one type of directional cue is more important than another, and how a relatively simple animal can decode complex visual stimuli. Warrant and Dreyer hope to tease out more answers in follow-up studies. Hopefully, the moths persist long enough for us to unravel their celestial secrets. The species was added to the endangered species list in 2021, after it experienced a 99.5 percent population decline amid massive drought.
