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Yahoo
4 days ago
- Science
- Yahoo
Invasive species undergoes mysterious change as it dominates Australia
Almost two centuries after rabbits were set free across Australia's fragile landscape, scientists are working to understand a mysterious change that has occurred in their physical nature. Oddly, the rabbits released from 1859 onwards have grown bigger than their European counterparts. The difference was noted in new research led by the University of Adelaide's Associate Professor Emma Sherratt, which studied the body sizes of 912 rabbits from around the world. 'We found Australian feral rabbits are quite a lot larger than European rabbits. We intend to find out why,' she said. It's hypothesised the changes could be due to "relaxed functional demands" on rabbits in Australia, because they face fewer threats from large predators. Physical developments have been observed in other feral animals released in Australia which give them an ecological advantage over native wildlife. In 2023, the Invasive Species Council noted that cane toads are changing in size and appearance as they adapt to different regions in Australia. As they expand west through Kakadu and into the Kimberly, cane toads at the edge of the "invasion front" have longer legs than those following them, allowing them to conquer new territory quickly. When you exclude the direct impact of humans, feral animals are responsible for more extinctions than anything else in Australia. Researchers are desperately working to give native species an edge by either genetically engineering them to avoid disease, or protecting them within dedicated sanctuaries. Native marsupials like the greater bilby once occupied up to 80 per cent of Australia's mainland. For thousands of years, throughout the night people would have seen the land teeming with the tiny creatures. Since European settlement, small marsupial numbers have dwindled, and conservationists have turned to protecting them inside fenced reserves. At the same time, feral rabbit numbers have exploded from an estimated 13 in 1859, to 200 million today, and scars from their warrens can be seen across the landscape. Meanwhile fewer than 10,000 greater bilbies survive. The researchers also examined rabbit skull shapes because changes in appearance indicate how they interact with their environment and what they feed on. 'Understanding how animals change when they become feral and invade new habitats helps us to predict what effect other invasive animals will have on our environment, and how we may mitigate their success,' Sherratt said. The work also included comparing the physical differences between rabbits that were raised for meat and fur, with wild animals. They found domesticated rabbit populations often didn't revert to their wild form after they were released into the environment. New detailed images released in fight to protect Australia from invasive pests Urgent plea to drivers after shocking dashcam footage emerges Call to stay vigilant as 'super' biosecurity threat spotted spreading over border 'While you might expect that a feral animal would revert to body types seen in wild populations, we found that feral rabbits' body size and skull-shape range is somewhere between wild and domestic rabbits, but also overlaps with them in large parts,' Sherratt said. 'Because the range is so variable and sometimes like neither wild nor domestic, feralisation in rabbits is not morphologically predictable if extrapolated from the wild or the domestic stock.' The research was published in the journal Proceedings of the Royal Society. Love Australia's weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week's best stories.
RNZ News
25-06-2025
- Science
- RNZ News
World's only known eyeless wasp discovered mummified in Nullarbor cave
By Peter de Kruijff , ABC The mummified remains of a male blind cave wasp found underground in the Nullarbor. Photo: Supplied/Jess Marsh Jess Marsh had spent 45 minutes crawling and twisting through the claustrophobic limestone tunnels of the Nullarbor Plain when she first saw it. Perched on the wall of a cave chamber was the almost perfect mummified remains of small, reddish wasp about 2 centimetres long with translucent wings. Its stand-out feature? It had no eyes. "This wasp is the only wasp in the world that is known to have adapted like that to a cave life," Dr Marsh said, an entomologist and arachnologist - an insect and spider expert - at the University of Adelaide. "The first specimen was actually climbing up the wall of the cave... like they'd been freeze-dried." University of Adelaide entomologist and arachnologist Jess Marsh collecting samples in a Nullarbor cave. Photo: Supplied/Steve Milner The preserved insect, yet to be taxonomically described, was one of the crowning discoveries from a research expedition in April with cavers from the Australian Speleological Federation (ASF). Eleven caves on the Western Australia side of the 200,000 square kilometre Nullarbor region were examined in a biological survey, funded by the Australian Research Council and the Hermon Slade Foundation. The caves were selected based on previous sightings of underground critters by cave-exploring citizen scientists. ASF president Andrew Stempel said the trip, which found specimens at five of the sites, had been an "incredible" collaboration connecting caver knowledge with expert scientists. "It took many years and many cavers and a lot of hard yards," he said. The wasp was found in a cave that contains passages that run for about 10 kilometres, which had previously been mapped out by scientists. It wasn't the only remains the researchers found either. The cave was full of thousands of mummified bodies of spiders, cockroaches, centipedes and other insects, preserved thanks to the salty cave conditions. A dead cockroach and centipede found preserved in a salty Nullarbor cave. Photo: Supplied/Steve Milner and Jess Marsh Dr Marsh said when she first locked eyes on the site she was captured by its otherworldly beauty. "It's not like anything I've ever seen before," she said. "[It had] the most amazing cave decorations I've ever seen, so stalactites, stalagmites and huge long salt straws [thin pillars of salt that sway in the cave breeze]. "It's like this weird world frozen in time that's completely dominated by invertebrates... some of the invertebrates have died almost mid-action." No living critters remain because of some sort of invertebrate world-ending cataclysm that occurred an unknown number of years ago. What excited Dr Marsh was the potential relationship between the blind arachnids and the wasp, which she thought was from the spider-hunting family called Pompilidae. Hundreds of dead invertebrates were found in a Nullarbor cave including a concentrated group of spiders in a spot dubbed "party rock". Photo: Supplied/Steve Milner "It's a really interesting story if they've both evolved to a cave-adapted lifestyle where they've lost their eyes independently but are linked through parasitism," she said. Collection manager at the Australian Museum - not part of the recent expedition - Matt Shaw said finding a wasp and spiders with regressed features was fantastic for science. "Because as [Charles] Darwin pointed out... regressed animals including cave animals were an important source of evidence for understanding evolution," he said. The exact age of the invertebrates in the mummy mausoleum was yet to be analysed, but Dr Marsh said they were so well preserved 'they could have died yesterday'". A dead Troglodiplura spider specimen could possibly be a new species. Photo: Supplied/Steve Milner Elsewhere on the trip, the expedition found some creatures that were still kicking, including two species of eyeless spiders. Both could fill up the palm of your hand but are incredibly different. One, which hangs underneath a web weaved between rocks is believed to be from the genus Tartarus, named after the prison for titans in Greek mythology. The second is large, hairy and probably part of the Troglodiplura genus, but distantly related to tarantulas, funnel webs and trapdoor spiders. "We don't know yet if it's a new species or if it's one of the already described ones," Dr Marsh said. There are five spiders in Troglodiplura, including four that were described only a few years ago from tiny fragments found in museum collections. Both Tartarus and Troglodiplura spiders have only been found on the Nullarbor. And there is a belief among arachnologists that some Nullarbor spider species may only be found in single caves rather than multiple sites. Dr Marsh said the latest trip, along with other research, challenged the idea the region was not particularly special for biodiversity. "The number and the diversity of species that may be surviving and living in the caves on the Nullarbor is actually much higher than we we initially thought," she said. A live web-weaving blind spider likely to be a member of the Tartarus genus. Photo: Supplied/Steve Milner With the growing knowledge of underground species comes a greater awareness of potential threats. In caves accessible to mammals, Dr Marsh said invasive foxes proposed a big threat to blind spiders. A site with living arachnids from the most recent trip had fox scat that contained spider fangs. "The risk of extinction for a lot of those [underground] species through development, impact by humans, changes to water movement across the landscape... is really very high," she said. While the South Australia side of the Nullarbor is in the process of being made a World Heritage site, the WA side is not. All of the recent cave surveys were done within an area ear-marked for the largest proposed green energy project in Australia. The 70 gigawatt Western Green Energy Hub would see about 3,000 turbines and six million solar panels installed across 20,000sqkm of land. The project has come under scrutiny from cavers concerned about potential impacts to the unique cave systems. Project chief executive Raymond Macdonald said less than five percent of the total surface area would be impacted, and that the company was currently mapping a directory of caves, sink holes and karst feature locations. "This new accuracy will ensure that significant features are totally avoided when selecting infrastructure locations," he said. The project's management is currently in discussion with state and federal regulators about what environmental studies will be needed as the project proposal is reviewed. An Indigenous land-use agreement is also being negotiated with the area's Traditional Owners, the Mirning. A WA Mirning People Aboriginal Corporation spokesperson said the whole ecosystem in the Nullarbor was significant. "Our priority is always to protect the environment as a whole, while placing particular emphasis on rare and endangered species," they said. - ABC
ABC News
24-06-2025
- Science
- ABC News
World's only known eyeless wasp discovered mummified in Nullarbor cave
Jess Marsh had spent 45 minutes crawling and twisting through the claustrophobic limestone tunnels of the Nullarbor Plain when she first saw it. Perched on the wall of a cave chamber was the almost perfect mummified remains of small, reddish wasp about 2 centimetres long with translucent wings. Its stand-out feature? It had no eyes. "This wasp is the only wasp in the world that is known to have adapted like that to a cave life," said Dr Marsh, an entomologist and arachnologist — an insect and spider expert — at the University of Adelaide. "The first specimen was actually climbing up the wall of the cave ... like they'd been freeze-dried." The preserved insect, yet to be taxonomically described, was one of the crowning discoveries from a research expedition in April with cavers from the Australian Speleological Federation (ASF). Eleven caves on the Western Australia side of the 200,000 square kilometre Nullarbor region were examined in a biological survey, funded by the Australian Research Council and the Hermon Slade Foundation. The caves were selected based on previous sightings of underground critters by cave-exploring citizen scientists. ASF president Andrew Stempel said the trip, which found specimens at five of the sites, had been an "incredible" collaboration connecting caver knowledge with expert scientists. "It took many years and many cavers and a lot of hard yards," he said. The wasp was found in a cave that contains passages that run for about 10 kilometres, which had previously been mapped out by scientists. It wasn't the only remains the researchers found either. The cave was full of thousands of mummified bodies of spiders, cockroaches, centipedes and other insects, preserved thanks to the salty cave conditions. Dr Marsh said when she first locked eyes on the site she was captured by its otherworldly beauty. "It's not like anything I've ever seen before," she said. "[It had] the most amazing cave decorations I've ever seen, so stalactites, stalagmites and huge long salt straws [thin pillars of salt that sway in the cave breeze]. No living critters remain because of some sort of invertebrate world-ending cataclysm that occurred an unknown number of years ago. What excited Dr Marsh was the potential relationship between the blind arachnids and the wasp, which she thought was from the spider-hunting family called Pompilidae. "It's a really interesting story if they've both evolved to a cave-adapted lifestyle where they've lost their eyes independently but are linked through parasitism," she said. Matt Shaw, a collection manager at the Australian Museum and not part of the recent expedition, said finding a wasp and spiders with regressed features was fantastic for science. "Because as [Charles] Darwin pointed out ... regressed animals including cave animals were an important source of evidence for understanding evolution," he said. The exact age of the invertebrates in the mummy mausoleum was yet to be analysed, but Dr Marsh said they were so well preserved "they could have died yesterday". Elsewhere on the trip, the expedition found some creatures that were still kicking, including two species of eyeless spiders. Both could fill up the palm of your hand but are incredibly different. One, which hangs underneath a web weaved between rocks is believed to be from the genus Tartarus, named after the prison for titans in Greek mythology. The second is large, hairy and probably part of the Troglodiplura genus but distantly related to tarantulas, funnel webs and trapdoor spiders. "We don't know yet if it's a new species or if it's one of the already described ones," Dr Marsh said. There are five spiders in Troglodiplura, including four that were described only a few years ago from tiny fragments found in museum collections. Both Tartarus and Troglodiplura spiders have only been found on the Nullarbor. And there is a belief among arachnologists that some Nullarbor spider species may only be found in single caves rather than multiple sites. Dr Marsh said the latest trip, along with other research, challenged the idea the region was not particularly special for biodiversity. "The number and the diversity of species that may be surviving and living in the caves on the Nullarbor is actually much higher than we we initially thought," she said. With the growing knowledge of underground species comes a greater awareness of potential threats. In caves accessible to mammals, Dr Marsh said invasive foxes proposed a big threat to blind spiders. A site with living arachnids from the most recent trip had fox scat that contained spider fangs. "The risk of extinction for a lot of those [underground] species through development, impact by humans, changes to water movement across the landscape ... is really very high," she said. While the South Australia side of the Nullarbor is in the process of being made a World Heritage site, the WA side is not. All of the recent cave surveys were done within an area ear-marked for the largest proposed green energy project in Australia. The 70 gigawatt Western Green Energy Hub would see about 3,000 turbines and six million solar panels installed across 20,000sqkm of land. The project has come under scrutiny from cavers concerned about potential impacts to the unique cave systems. Project chief executive Raymond Macdonald said less than 5 per cent of the total surface area would be impacted, and that the company was currently mapping a directory of caves, sink holes and karst feature locations. "This new accuracy will ensure that significant features are totally avoided when selecting infrastructure locations," he said. The project's management is currently in discussion with state and federal regulators about what environmental studies will be needed as the project proposal is reviewed. An Indigenous land-use agreement is also being negotiated with the area's Traditional Owners, the Mirning. A WA Mirning People Aboriginal Corporation spokesperson said the whole ecosystem in the Nullarbor was significant. "Our priority is always to protect the environment as a whole, while placing particular emphasis on rare and endangered species," they said.
ABC News
15-06-2025
- General
- ABC News
Push to reduce ACT school zone speed limit to 30kph
Just like countless young families across the ACT, Veronica Fortune and her children love walking to school most days. But there are dangers. The biggest one is the volume of traffic at pick-up and drop-off times. Parents, public servants, tradies and teenagers all drive, jam and jostle through the bumper-to-bumper snarl. And just like every road, some motorists don't care about the laws. "I've had a near-miss myself … thankfully, I had my sons in a pram at that time and my daughter was standing right next to me," she said. Veronica said the road past her local school is an accident waiting to happen. She's written to members of the ACT Legislative Assembly and submitted a petition about safety improvements that can be made. "Speed bumps are not close enough to the crossing and we may need more of them. A wombat crossing [raised zebra crossing] … would really help because it would force cars to slow down right before they got to where children are." Veronica has also pushed for adjustments to the surrounding roads, but so far, nothing has changed. The key improvement, according to new research focused on the ACT by a University of Adelaide team, would be to change the rules that govern school zones. Dr James Thompson is a road safety expert based at the Centre for Automotive Safety Research who led the research. He said reducing everyone's speed was crucial, and that 30kph was the tipping point. "But if you're hit under 30 kilometres, you have a pretty good chance of surviving." The evidence the team collected points to a clear recommendation — that the speed limit in ACT school zones should be 30kph or less. South Australia is the only state or territory in Australia that has a sub-40kph school zone limit (25kph) with that being standard practice there for decades. He was surprised during the work by his team at just how many motorists sped through school zones across the ACT, especially during "active" school zone times (36 per cent) and when the default road speed limit was 60kph (50 per cent). Along with installing "traffic calming measures" such as speed bumps and narrower lane widths in all school zones, the report recommends extending the school zone time limits in the ACT. This would mean 7am-5pm Monday to Friday (replacing the ACT's existing 8.30am to 4pm) to protect children at pre- and post-school care, lunchtime and other extracurricular activities such as sport. Dr Thompson acknowledged these would be big shifts, but is unequivocal these moves must be made. "You know, when are we going to start taking the safety of school children seriously?" he asked. The ABC has spoken with several school communities, and they all say speeding traffic in and around schools is a constant danger for pedestrians. The risk is exacerbated by many schools being surrounded by 60 and 80kph roads. Earlier this year, the principal of St Clare's College Dr Ann Cleary led a months-long consultation asking families about road and pedestrian risks that surround St Clare's, with over 200 families making a submission. "That's a huge response, which first tells me parents are really taken by the topic" she said. St Clare's is next to St Edmunds College, which faced near-tragedy earlier this year when two students were seriously injured by a speeding driver while they were walking to school. Both colleges are located next to several roads that pose significant risks to pedestrians. The concerns reported in St Clare's survey were numerous, but those that repeatedly came up the surrounding 60kph roads, bus drop-off/pick-up areas and other hazards within the designated school zone. Dr Cleary believes families would support a 30kph school zone speed limit and extended school zone times, but that the 60kph roads immediately around St Clare's need to be reviewed too. Dr Cleary cited the University of Adelaide research that found "the higher the speed limit outside of school zone times or places, the more likely cars are to speed through the school zone". She also highlighted the need for flashing or electronic signs, to stand out from what she described a "white noise" of road markings and symbols in the area. The ACT government wasn't available for an interview to discuss the likelihood of changing school zone speeds and times (as well as other recommendations in the University of Adelaide report). In a statement, a spokesperson said the "ACT government welcomes the outcomes of the research and will consider future actions as part of the current development of the next ACT Road Safety Strategy". Change can't come soon enough for the people who prioritise children's safety. Dr James Thompson is convinced that ACT residents, and those in other jurisdictions, are ready and willing. "If you explain to them what's at risk and what can be gained by improving the safety of school zones, they would absolutely get on board with it. So it's a funny thing … that we haven't had that change in all the other jurisdictions." Veronica Fortune's desire for change is driven by a simple hope.
Forbes
04-06-2025
- Science
- Forbes
When The Sahara Was Green By Martin Williams — Review
The fascinating but little-known history of how the Sahara was transformed from a pleasant green and fertile land into the largest hot desert in the world. Green Sahara. (Collage by Kuat Abeshev. Credits for images used in the collage: Photo by David Clode ... More on Unsplash; Photo by Mark Eder on Unsplash; Photo by David Clode on Unsplash.) It is probably unimaginable to most of us to learn that there was a time only 5,000 years ago, when the Sahara was not a desert at all. Instead, it was a green and fertile woodland and vast grassy savannah that hosted a plethora of lakes and rivers, and home to countless dinosaurs that roamed freely across the land. Later, prehistoric hunters and farmers lived in the Sahara alongside a veritable zoo of iconic African wildlife, including elephants, giraffes, hippos, a variety of gazelles, Nile perch, crocodiles, aurochs, Neolithic cattle, turtles, and an enormous collection of large trees and plants. All this, according to earth scientist Martin Williams, an Emeritus Professor at the University of Adelaide and a world authority on climatic and environmental change. In his captivating memoir, When the Sahara Was Green: How Our Greatest Desert Came to Be (Princeton University Press; 2023/2024), Professor Williams shares stories from his lifetime devoted to researching and exploring the Sahara Desert to provide us with a fascinating and readable overview of the surprisingly complex climate and geography of the Sahara. Professor Williams discusses the evidence that supports the answers that scientists know to some very basic questions, including; why was the Sahara previously much wetter than it is now, and will it become wetter again? ('Not for a long time,' p. 180). Did humans contribute to the Sahara's desertification? ('NO!' Pp. 143; 144-145). And where does all that sand come from? (Chapters 5 & 6). Paperback cover: When the Sahara Was Green by Martin Williams (Princeton University Press, ... More 2023/2024). Professor Williams points out that the Sahara Desert isn't actually all sand. Contrary to popular belief, sandy areas comprise only about 20% of the Sahara. Much of the Sahara consists of gravel along with extensive plateaus and – yes – rocky mountains. Divided into three parts, this readable history begins when the supercontinent Gondwana first appeared 7 million years ago, and follows its journey as it broke apart into major land masses: South America, Africa, Antarctica, Australia, Zealandia, Arabia, and the Indian subcontinent. Professor Williams also explores and explains ancient glaciations, historic sea level fluctuations, the geological and climatological reasons for why the Green Sahara dried out and became a desert, and how the very old basement rock underlying Africa still influences what happens on the surface today. Compelling writing and profound knowledge are carefully combined with deep history, decades of field work, personal observations and experiences. In this meticulously researched book, Professor Williams explores a wide variety of topics from the geological and climatic changes that influenced human evolution and created the Sahara as we know it, to modern environmental and political issues that confront us today. Throughout the entire book, Professor Williams' fundamental knowledge of the region's geology, archaeology and ecology makes this book rewarding and fascinating reading. The book includes lots of maps, photographs, drawings and diagrams to illustrate the regions and concepts that Professor Williams discusses in the text. One piece of advice I have is to use sticky notes as bookmarkers for maps 1, 2 and 3 because you will be referring to these maps many times as you read the book. I was perhaps most surprised by all the ancient human artifacts, pottery – some packed with fossilized fruits – arrowheads and other stone tools, and even some fossilized bones from ancient humans as well as the animals they interacted with, just lying on the surface of the sand or gravel. Mind-boggling. The anecdotes and first-hand experiences described herein make for tremendously compelling storytelling, and could only come from someone who has spent his life researching and working in the region. Professor Williams exhibits an astonishing depth and breadth of knowledge throughout the entire book, and is generous with his explanations of the scientific evidence to the reader. The Sahara Desert is a powerful warning of what the entire world is facing and the conclusions the author reaches have far-reaching implications beyond north Africa, especially as climate change progresses ever more rapidly. This important book is highly recommended for everyone interested in environmental history or law, or prehistory, and students of any of the sciences will learn a lot from reading it. © Copyright by GrrlScientist | hosted by Forbes | Socials: Bluesky | CounterSocial | Gab | LinkedIn | Mastodon Science | Spoutible | SubStack | Threads | Tribel | Tumblr | Twitter
