Nature Signals Podcast

Ruth Thornton

A newsletter about nature, the animals and plants that share the world with us and the human actions affecting it - both good and bad. ruththornton.substack.com

  1. 1d ago

    The hidden costs of beautiful gardens: How invasive plants rewrite butterfly romance

    In this episode, we explore fascinating new research showing that invasive ornamental plants don't just outcompete native vegetation—they can also change the appearance of butterflies, making them less attractive to potential mates. The discovery reveals a previously unknown way that invasive plants can affect wildlife, raising fresh concerns for butterfly conservation and the long-term health of ecosystems. Researchers in Japan found that the caterpillars of the rare Fischer's blue butterfly (Tongeia fischeri) developed differently depending on the plant they fed on. Caterpillars raised on an invasive succulent grew into adults with altered wing coloration, particularly in ultraviolet wavelengths. Male butterflies showed a clear preference for females raised on their native host plant, suggesting that an invasive species could indirectly reduce reproductive success. The findings highlight an important lesson in conservation biology: even when wildlife appears to adapt to environmental change, hidden biological costs may emerge that threaten populations over time. If similar effects occur in other insects, the ecological consequences of invasive plants could be far greater than previously recognized. The episode features Karen Hisai and professor Norio Hirai of Osaka Metropolitan University in Japan. In This Episode: Why invasive ornamental plants are spreading beyond gardens. How caterpillar diet influences adult butterfly appearance. The surprising role ultraviolet wing patterns play in butterfly courtship. Why male butterflies preferred females raised on native plants. What the research means for butterfly conservation. How invasive species may affect wildlife in subtle, previously overlooked ways. Why protecting native plants remains essential for healthy ecosystems. Why This Research Matters Conservation efforts often focus on preserving habitat and reducing direct threats such as pesticides or climate change. This study suggests another challenge may be hiding in plain sight. As invasive plants spread into natural ecosystems, they may subtly alter the biology and behavior of native insects—not by killing them outright, but by changing how they communicate, recognize one another and reproduce. Those hidden effects could ultimately determine whether vulnerable butterfly populations recover or continue to decline. Resources and links: Hisai et al., 2026, Effects of alien host plant on wing coloration and mating behavior of an endangered butterfly. Basic and Applied Ecology, 92:13-19. Shackleton et al., 2022. Consensus and controversy in the discipline of invasion science. In Conservation Biology, 36(5):e13931. Jeratthitikul et al., 2013. Phylogeography of Fischer's blue, Tongeia fischeri, in Japan: Evidence for introgressive hybridization. Molecular Phylogenetics and Evolution, 66(1):316-26. Get full access to Nature Signals at ruththornton.substack.com/subscribe

  2. Jul 9

    The State of Nature Update #27

    This week, we cover six fascinating stories from the world of wildlife and conservation. Discover how scientists are working to save Ukraine's European bison despite the ongoing war, and how environmental DNA (eDNA) is revolutionizing biodiversity research by revealing entire ecosystems from a single water sample. We also explore surprising evidence that ancient ground squirrels scavenged mammoths, bison, and other Ice Age giants, examine the controversial roundup of wild horses in California, and discuss new research suggesting wireless radio frequency radiation may disrupt bats' navigation. Finally, we look at growing bipartisan support for wildlife crossings across the United States, helping reconnect habitats while reducing deadly and costly collisions between animals and vehicles.   Key Points: 0:54 - The struggle to save Ukraine's bison amid the war. 3:57 - Unlocking nature's secrets through 'environmental DNA.' 6:01 -  Ancient ground squirrel poop uncovered an astonishing diet of mammoths, bison, and even large cats. 7:34 - Controversial Roundup of 450 wild horses proceeds in California. 9:08 – Wireless radiation disrupts bats' flight patterns in new study. 10:19 - Wildlife crossings gain legislative support in four U.S. states.  Links to articles and resources: BioGraphic, 6/2/2026, by Dustin Patar: Saving bison as bombs fall IUCN Red List: European bison (Bison bonasus) World Wide Fund for Nature in Ukraine: WWF-Ukraine The Conversation, 7/7/2026, by Jenny Whilde: Fishing for DNA - how a cup of river water can reveal secrets about human health, pollution and biodiversity. Nature, 6/9/2026, by Ewen Callaway: Ancient ground squirrels feasted on carcasses like 'zombies of the Pleistocene.' Murchie et al., 2026. Ground squirrel coprolites preserve complex archives of ancient environmental DNA over 700,000 years. Los Angeles Times, 6/30/2026, by Lila Seidman: 450 wild horses face a roundup in Eastern Sierra as feds proceed with contested plan. U.S. Forest Service press release, 6/22/2026: Inyo wild horse gather starts July 8. Environmental Health News, 6/5/2026: Study finds EMF radiation exposure disrupts bat behavior for hours. Lindecke et al., 2026. Disruptive effects of brief radiofrequency noise exposure on migratory bat navigation. Pew Research Center, 6/30/2026, by Carol Kaufman: States act to reduce wildlife collisions. Scioto Analysis, 3/10/2025: Scioto Analysis releases cost-benefit analysis of wildlife crossings. Get full access to Nature Signals at ruththornton.substack.com/subscribe

  3. Jul 2

    How Scientists Are Giving Rare Turtle Babies a Head Start on Life

    How can scientists help endangered turtles survive? In this episode, we explore how wildlife conservation professionals in Michigan are using a technique called "headstarting" to raise rare baby turtles in captivity before releasing them into the wild. You'll learn why young turtles face such steep odds from predators, habitat loss, road mortality, and the illegal pet trade, and how researchers are measuring whether this approach can rebuild wild populations. We also discuss the importance of protecting wetlands and why captive rearing is only one piece of the conservation puzzle. It's a story about endangered species recovery, hands-on science, and what it takes to give wildlife a better chance at survival. The episode features Bill Flanagan of John Ball Zoo, Will Miller of Calvin University, and Dan Earl of the Michigan Natural Features Inventory.   Key Points: 1:01 – Testing if headstarting might help spotted turtles 2:00 – Combining conservation and educating the next generation of biologists 3:17 – Spotted turtles’ reclusive habits make them difficult to study 4:44 – Dangers from the illegal pet trade 5:25 – Aging ‘ghost populations’ concern researchers 6:09 – What you can do to help turtles   Resources & Links: IUCN Red List: Spotted Turtle IUCN Red List: Eastern Box Turtle International Convention on Wetlands: Global Wetland Outlook 2025 United Nations Sustainable Development Goals Report Michigan EGLE: Status and Trends of Michigan's Wetlands: Pre-European Settlement to 2005 John Ball Zoo's Great Lakes Rare Turtles Program Michigan Herp Atlas Turtle Survival Alliance Cornell Wildlife Health Lab: What the heck is herping? Get full access to Nature Signals at ruththornton.substack.com/subscribe

  4. Jun 25

    Climate change is already causing local extinctions. The biggest surprise is where.

    Scientists long assumed tropical species would be hit hardest by climate change. But a new global study found that animals and plants in temperate regions, including North America and Europe, are already disappearing from parts of their range at alarming rates. We explore how wildlife and plants are responding to warming temperatures, why local extinctions are rising around the world, why many species aren’t moving into cooler habitats, and what the findings mean for biodiversity and conservation. The episode also features Dr. John J. Wiens, a professor at the University of Arizona, and Dr. Gopal Murali, a former postdoctoral researcher at the University of Arizona. Key points:  1:07 - Digging through the data to track survival of animals and plants over time. 2:34 - Nearly half of species in temperate zones have disappeared from parts of their range. 3:40 - The world has gotten hotter. 4:45 - Most temperate species are not moving north in response to climate change. 5:47 - What it means for conservation. Useful resources: Murali, G., Karger, D.N. & Wiens, J.J. Temperate local extinctions from climate change are outpacing tropical extinctions. Nat. Clim. Chang. (2026). Kristen E. Saban, John J. Wiens; Unpacking the extinction crisis: rates, patterns and causes of recent extinctions in plants and animals. Proc Biol Sci. (2025) World Meteorological Organization: 2025 State of Climate Report. Berkeley Earth: Global Temperature Report for 2025. New York Times, 5/26/2026, by Brad Plumer and Eric Niiler: Why scientists retired the dire climate scenario used for over a decade. NOAA's Science on a Sphere program: Climate Model: Temperature Change (RCP 8.5) - 2006 - 2100. European Commission: Five things you should know about climate scenarios. Get full access to Nature Signals at ruththornton.substack.com/subscribe

  5. Jun 10

    The State of Nature Update #26 Podcast

    This episode explores six biodiversity stories from around the world: how elephant dung supports diverse dung beetle communities that drive nutrient cycling and seed dispersal in African ecosystems; the death of the last known Sacramento Mountains checkerspot caterpillar, which could mean that the rare butterfly is now extinct; surprising new evidence that daddy longlegs in South America can hunt and kill frogs despite their seemingly harmless appearance;  the tagging of a nesting female sea turtle in Ecuador to better understand migration routes and reduce deadly fishing-net entanglements of eastern Pacific leatherback turtles; how an Italian farm is using forest-inspired, biodiversity-rich practices to build resilience against climate change while improving soil health; and it considers the argument that restoring and protecting nature may be one of the most effective climate solutions, simultaneously storing carbon, supporting biodiversity, and benefiting local communities. Key points: 1:01 – Elephant poop’s essential role in African ecosystems, thanks to dunk beetles. 4:04 - The last known caterpillar of a rare butterfly has died, all but eliminating all hope of reviving the species. 5:43 - Daddy longlegs don’t just eat insects - they also hunt down frogs. 7:15 - Scientists tagged a rare sea turtle while she was laying eggs, hoping to discover her migration and feeding patterns to help with conservation decisions. 8:18 - Incorporating nature into farming practices to make crops resilient to climate change. 10:47 - Biodiversity conservation as a solution for climate change. Articles & Resources: Anthropocene Magazine, 5/28/2026, by Warren Cornwall: What happens to the small things when the big things disappear? Gijsman, Nutter, and Pringle, 2026: Importance of elephants for dung beetle diversity and ecosystem functions. Science: 392(6801). The New York Times, 5/21/2026, by Catrin Einhorn: A very lonely caterpillar, possibly the last of its kind, has died The New York Times, 3/6/2025, by Catrin Einhorn and Harry Stevens: See how butterflies are surviving, or not, near you. Scientific American, 5/21/2026, by Jake Buehler: Daddy longlegs are actually bloodthirsty killers - of frogs. Calvache et al., 2026: Harvestmen (Arachnida: Opiliones) as overlooked predators of anurans in the neotropics. Ecology and Evolution: 16 (4). Mongabay, 5/26/2026, by Bobby Bascomb: Tracking Lucero: Scientists follow a rare Eastern Pacific leatherback sea turtle. IUCN: Leatherback turtle (Dermochelys coriacea). Atmos, 5/25/2026, by Becca Warner: For more successful farming, follow the forest. Biomimicry Center, Arizona State University. The Guardian, 5/24/2026, editorial: Could nature itself hold the solution to climate change? Get full access to Nature Signals at ruththornton.substack.com/subscribe

  6. Jun 3

    Podcast: Hidden 'forever chemicals' found in Great Lakes fish raise new health concerns

    A recent study found dozens of previously unidentified PFAS, or “forever chemicals,” in Lake Huron’s water, fish and mussels, suggesting contamination is more widespread than previously thought. Some PFAS are linked to serious health risks, but most of the thousands of PFAS compounds in use remain poorly studied. The episode features Clarkson University environmental chemist Bernard Crimmins, who explains the advanced testing method the researchers used to find new PFAS chemicals, a fishing charter captain describing his concerns around PFAS and other contaminants in fish in the Great Lakes, and a Michigan representative who talks about a bill she introduced to limit PFAS in consumer products but which failed. Together, their insights highlight the growing challenge of understanding the health and environmental impacts of PFAS pollution across the Great Lakes region and globally. Key points: 1:29 – A 2025 study finds dozens of previously unknown PFAS chemicals in the fish, mussels, and waters of Lake Huron. 3:55 – “Captain Steve” Hubert with Chum Bucket Charters explains his concerns about PFAS in fish and their potential impact on his business. 4:42 – Gillian Miller with Ecology Center outlines the state and federal regulatory structure. 6:06 – A 2024 Michigan bill attempts to limit PFAS in consumer products but is not passed.  Resources: To read this article, check out my Substack newsletter Nature Signals. Resources: Study: Ren et al., 2025. Suspect screening and nontargeted analysis of polyfluoroalkyl substances in Lake Huron water and biota. Journal of Great Lakes Research, 51(2):102507. National Institute of Environmental Health Sciences: Perfluoroalkyl and polyfluoroalkyl substances (PFAS). European Food Safety Authority: Per- and polyfluoroalkyl substances (PFAS). U.S. Environmental Protection Agency: PFAS explained.  Study: Yu et al., 2025. A global overview of per- and polyfluoroalkyl substance regulatory strategies and their environmental impact. Toxics, 13(4): 251. Michigan Eat Safe Fish Guides. Get full access to Nature Signals at ruththornton.substack.com/subscribe

  7. May 20

    Podcast: The State of Nature Update #25

    Summary: This episode of Nature Signals examines recent biodiversity and environmental news, ranging from bird behavior to wolf-moose dynamics and plastic pollution. You’ll hear about how Hawaiian songbirds steal nesting materials from one another, why European city birds fear women more than men, how wolf reintroduction on Isle Royale has successfully reduced an overabundant moose population, and about the botched rescue attempt of “Timmy” the humpback whale. It concludes with research showing that toxic chemicals and climate change together harm fertility in humans and wildlife, but just one week of reduced plastic exposure can significantly lower hormone-disrupting chemicals in people. Key points: Biodiversity: 0:54 - Some birds steal nesting materials from other nests, adding to their threats 2:37 - City birds appear to be more afraid of women than of men, for unknown reasons 3:42 - More wolves are thriving on Isle Royale than in nearly 50 years 5:00 - The botched rescue attempt of Timmy, the humpback whale stranded in Germany Pollution & Plastics 8:02 - Toxic chemicals and climate change work together to harm fertility across species 8:54 - Seven days without plastic contact slashes chemicals in the body   Resources: To read this article, check out my Substack newsletter Nature Signals. Articles & Resources: The New York Times, 5/12/2026, by Sara Novak: Building nests is hard. That’s why some birds steal. Wilson Ranking et al., 2026, Upcycling in the Hawaiian islands: Native forest birds commonly engage in nest material kleptoparasitism. American Naturalist. Scientific American, 4/28/2026, by Blaire Cameron: City birds appear to be more afraid of women than men, and scientists have no idea why. Morelli et al., 2025, Sex matters: European urban birds flee approaching women sooner than approaching men. People and Nature: 8(2): 316-326. MLive, 4/27/2026, by Tanda Gmiter: Isle Royale’s wolf population surges to highest numbers in nearly 50 years. Michigan Technological University, 4/27/2026, by Cyndi Perkins: Isle Royale wolf population nears historic high as moose numbers plummet. Isle Royale Wolf-Moose Project annual reports. Science, 5/4/2026, by Martin Enserink: Chaotic whale rescue shocks marine scientists. The Guardian, 5/5/2026, by Kate Connolly: Rescue of Timmy the whale ‘an all-round catastrophe’ after tracker failure. IFAW News, 5/11/2026: Timmy the whale and the limits of good intentions. The Guardian, 5/15/2026, by Patrick Greenfield: What the fate of Timmy the whale says about conservation. EHN, 5/1/2026, by Staff: Toxic chemicals and climate change work together to harm fertility across species. Brander et al., 2026, Impacts of environmental stressors on fertility and fecundity across taxa, with implications for planetary health.NPJ Emerging Contaminants: 2, 12. Medical Xpress, 4/22/2026, by Sadie Harley: Seven days without plastic contact slashes phthalates and bisphenols in body. Harray et al., 2026, Low-plastic diet and urinary levels of plastic-associated phthalates and bisphenols: the randomized controlled PERTH trial. Nature Medicine. Get full access to Nature Signals at ruththornton.substack.com/subscribe

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A newsletter about nature, the animals and plants that share the world with us and the human actions affecting it - both good and bad. ruththornton.substack.com