Dragonflies Make Epic Migrations, But Climate Change Could Foil Their Itineraries
By Jason Bittel
It's that time of year again: Right now, monarch butterflies are taking wing in the mountains of northwestern Mexico and starting to flap their way across the United States.
The great monarch migration always makes headlines, in part because climate change, along with our pesticides and agricultural monocultures, threatens to erase the natural spectacle, but also because this natural phenomenon is simply amazing. The trip of nearly 5,000 miles is an unlikely one for an insect, but these butterflies don't have a monopoly on the massive, multigenerational migration game.
It's time to give some love to the epic feats of dragonflies.
According to a study published by the Royal Society last fall, common green darners, which are found from Cuba to Canada, make a long, complex journey that takes three generations and spans a distance of more than 1,500 miles. Scientists are still trying to figure out exactly how they do it, but temperature seems to play a key role in telling the animals when to move. Unfortunately, this means climate change could well wreck the whole event even before we fully understand it. Worse, it would leave much of eastern North America without an important member of its food web.
The news that dragonflies migrate probably won't shock people who study insects, says the study's senior author, Colin Studds, a wildlife ecologist at the University of Maryland. "We've had an inkling of how many insects migrate," he said. "There are moths, there are beetles, and there are probably about 20 species of dragonflies that we have expected of migration. But we don't know much about it other than that it's a phenomenon."
One of the reasons why insect migration remains so much of a mystery is that bugs are tough to track. They're tiny, they die all the time, and they're quick as heck — especially dragonflies. "Unlike monarchs, common green darners are fast fliers," said MaLisa Spring, state coordinator for the Ohio Dragonfly Survey at the Museum of Biological Diversity just north of Columbus. "This makes them hard to catch and potentially add identification tags or stickers, and even harder to photograph. Most photo observations are a blur of blue and green, so a tiny sticker doesn't work so well."
This is why Studds and his coauthors decided to study where the dragonflies had been, rather than where the critters were heading. To do this, they took tissue samples from the wings of more than 850 green darners, some collected from the wild and others from museum specimens going back 140 years. A molecular analysis of the wings allowed the scientists to identify hydrogen isotopes that revealed the latitudes at which the dragonflies were born. (These isotopes vary at reliable rates as one moves north or south, so determining which ones are present and in what quantities can drop a pin of origin within about 100 to 200 miles.)
The team also made use of 21 years' worth of citizen science data to understand when and under what conditions dragonflies appear across their vast range. With all of these pieces put together, common green darner migration patterns are no longer so much of a blue-green blur.
Tina Vance / Flickr
In February the dragonflies appear only in warm latitudes, which is reflected in data showing dragonfly emergences at this time in Florida, Louisiana and Texas, as well as Puerto Rico, Cuba and southern Mexico. But come March, this first generation has already winged it up to the American Northeast, the Great Lakes region and southern Canada. And then those well-traveled dragonflies mate, lay eggs and die.
In May and June, the second generation hatches onto the scene. Some live their whole lives locally, but others — driven by what, we do not know — point their beautiful compound eyes south. Between September and November, these snowbirds don floral shirts and sunglasses and can be found flitting around the southern U.S. and Caribbean. Like the first generation, these dragonflies mate, lay eggs and die.
This leaves us with the third generation in the cycle, which are the population's homebodies. Because winter hits the south soon after they hatch, and they definitely don't want to head north to even colder climes, these lucky darners live out their life span locally. And then they ... mate, lay eggs and die like the rest. Their offspring then hatch around February, transform from larvae to adults, and head up north, starting the cycle anew.
The great dragonfly migration has likely been taking place for many millennia. Each generation has a job to do and an itinerary to follow, and every step is tied to a specific temperature range.
"So one of the things that we figured out from the citizen science data of over 20 years across the whole eastern United States is that the dragonflies don't begin migrating until it gets to about 9.5 degrees Celsius, or just shy of 50 degrees Fahrenheit," said Studds. "They kind of wait for it to go up to that point and they follow that temperature north."
Enter climate change. Temperature patterns are shifting all over the U.S. (indeed, the whole planet), and research on monarchs is already showing that such fluctuations may affect how the butterflies inoculate themselves against parasites. Could there be similar consequences for other migratory insects?
"If we are moving into a period where winter temperatures are warming and spring temperatures are getting warmer through time, then that will probably affect the entire timing and pace of dragonfly migration," said Studds. "It will affect how far north they go and how quickly they develop."
In some areas, warmer temperatures year-round may mean dragonflies won't even need to migrate at all. This isn't necessarily bad for the darners, mind you. But because dragonflies are important predators of mosquitoes, aphids, and other insects, as well as nutritious food for ducks, toads, newts, fish and even carnivorous plants like sundew, losing a seasonal influx of these creatures could ripple out through North America's ecosystems. (Plus, dragonflies are beautiful, and people up north will miss them.)
The truth is, scientists still know very little about how these seasonal shake-ups will affect wildlife, and common green darners and monarch butterflies are just two species among many that are facing big changes. But given that insects are experiencing dramatic declines worldwide, we need to unpack as many of these little mysteries as we can now — instead of trying to piece the puzzle back together after it's too late.
Reposted with permission from our media associate onEarth.
The survey compared six environmental concerns: drinking water pollution; pollution in rivers, lakes and reservoirs; tropical rainforest loss; climate change; air pollution; and plant and animal species extinction. While most Americans showed concern for all of these threats, the majority were most worried about polluted drinking water (56 percent), followed by polluted rivers, lakes and reservoirs (53 percent), Gallup reported.
"When it comes to environmental problems, Americans remain most concerned about two that have immediate and personal potential effects," Gallup noted. "For the past 20 years, worries about water pollution – both drinking water and bodies of water — have ranked at the top of the list. The water crisis in Flint, Michigan, laid bare the dangers of contaminated drinking water and no doubt sticks in the public's minds."
According to a new study, 61.4 million people in the U.S. did not drink their tap water as of 2018, Asher Rosinger, an assistant professor of biobehavioral health, anthropology and demography at Penn State, wrote in The Conversation.
"It's important not to blame people for distrusting what comes out of their tap, because those fears are rooted in history," Rosinger explained.
Meanwhile, U.S. Environmental Protection Agency surveys found that almost 50 percent of rivers and streams and more than one-third of lakes are polluted and unfit for swimming, fishing and drinking, the Natural Resources Defense Council reported. Without action, concerns over water quality will become increasingly relevant as the demand for fresh water is expected to be one-third greater by 2050 than it is today.
Gallup researchers have tracked environmental concerns among Americans since 2000, and water quality worries have consistently ranked high, Gallup noted.
The survey also revealed an environmental partisan divide between Democrats and Republicans. For example, 68 percent of Democrats were highly concerned about global warming compared to 14 percent of Republicans.
Another recent Gallup survey found that 82 percent of Democrats believed that global warming effects had already started compared to 29 percent of Republicans. "That's a gap of 53 points; for comparison, in 2001, the gap was a mere 13 points," Grist reported.
Similarly, a 2020 Pew Research Center report revealed the widest partisan gap to date concerning whether or not climate change should be a top policy priority. Protecting air and water quality ranked as the second most divisive issue among Republicans and Democrats, The New York Times reported.
"Intense partisan polarization over these two issues in particular" has been growing for decades, Riley Dunlap, a professor emeritus at Oklahoma State University, told The New York Times last February. "Voters take cues on their policy preferences and overall positions," he added. "President Trump has, in the past, called climate change a hoax and all that. You get a similar message from many members of Congress on the Republican side. And most importantly, it's the message you get from the conservative media."
Gallup's latest figures also showed that concern about environmental threats either increased or remained the same between 2019 and 2020.
"The fluctuations in worry levels since 2019 are largely driven by Democrats and Democratic-leaning independents, who became more worried, on average, about the six environmental problems in 2020 during the presidential campaign and are now less worried with Joe Biden as president," Gallup reported.
While surveys like these are "not a full-blown diagnostic rundown of the nation's psyche," they are informative tools for understanding how and what Americans are feeling and thinking, Grist reported.
Climate Change Threatens Coffee – But We’ve Found a Wild Species That Could Help Save Your Morning Brew
By Aaron P Davis
The world loves coffee. More precisely, it loves arabica coffee. From the smell of its freshly ground beans through to the very last sip, arabica is a sensory delight.
Robusta, the other mainstream coffee crop species, is almost as widely traded as arabica, but it falls short on flavor. Robusta is mainly used for instant coffee and blends, while arabica is the preserve of discerning baristas and expensive espressos.
Consumers may be happy, but climate change is making coffee farmers bitter. Diseases and pests are becoming more common and severe as temperatures rise. The fungal infection known as coffee leaf rust has devastated plantations in Central and South America. And while robusta crops tend to be more resistant, they need plenty of rain – a tall order as droughts proliferate.
The future for coffee farming looks difficult, if not bleak. But one of the more promising solutions involves developing new, more resilient coffee crops. Not only will these new coffees have to tolerate higher temperatures and less predictable rainfall, they'll also have to continue satisfying consumer expectations for taste and smell.
Finding this perfect combination of traits in a new species seemed remote. But in newly published research, my colleagues and I have revealed a little-known wild coffee species that could be the best candidate yet.
Coffee Farming in a Warming World
Coffea stenophylla was first described as a new species from Sierra Leone in 1834. It was farmed across the wetter parts of upper west Africa until the early 20th century, when it was replaced by the newly discovered and more productive robusta, and largely forgotten by the coffee industry. It continued to grow wild in the humid forests of Guinea, Sierra Leone and Ivory Coast, where it became threatened by deforestation.
At the end of 2018, we found stenophylla in Sierra Leone after searching for several years, but failed to find any trees in fruit until mid-2020, when a 10g sample was recovered for tasting.
Field botanists of the 19th century had long proclaimed the superior taste of stenophylla coffee, and also recorded its resistance to coffee leaf rust and drought. Those early tasters were often inexperienced though, and our expectations were low before the first tasting in the summer of 2020. That all changed once I'd sampled the first cup on a panel with five other coffee experts. Those first sips were revelatory: it was like expecting vinegar and getting champagne.
This initial tasting in London was followed by a thorough evaluation of the coffee's flavour in southern France, led by my research colleague Delpine Mieulet. Mieulet assembled 18 coffee connoisseurs for a blind taste test and they reported a complex profile for stenophylla coffee, with natural sweetness, medium-high acidity, fruitiness, and good body, as one would expect from high-quality arabica.
C. stenophylla growing in the wild, Ivory Coast. E. Couturon / IRD, Author provided
In fact, the coffee seemed very similar to arabica. At the London tasting, the Sierra Leone sample was compared to arabica from Rwanda. In the blind French tasting, most of the judges (81%) said stenophylla tasted like arabica, compared to 98% and 44% for the two arabica control samples, and 7% for a robusta sample.
The coffee tasting experts picked up on notes of peach, blackcurrant, mandarin, honey, light black tea, jasmine, chocolate, caramel and elderflower syrup. In essence, stenophylla coffee is delicious. And despite scoring highly for its similarity to arabica, the stenophylla coffee sample was identified as something entirely unique by 47% of the judges. That means there may be a new market niche for this rediscovered coffee to fill.
The taste testers approved of stenophylla's sweet and fruity flavour. CIRAD, Author provided
Breaking New Grounds
Until now, no other wild coffee species has come close to arabica for its superior taste. Scientifically, the results are compelling because we would simply not expect stenophylla to taste like arabica. These two species are not closely related, they originated on opposite sides of the African continent and the climates in which they grow are very different. They also look nothing alike: stenophylla has black fruit and more complex flowers while arabica cherries are red.
It was always assumed that high-quality coffee was the preserve of arabica – originally from the forests of Ethiopia and South Sudan – and particularly when grown at elevations above 1,500 metres, where the climate is cooler and the light is better.
Stenophylla coffee breaks these rules. Endemic to Guinea, Sierra Leone and Ivory Coast, stenophylla grows in hot conditions at low elevations. Specifically it grows at a mean annual temperature of 24.9°C – 1.9°C higher than robusta, and up to 6.8°C higher than arabica. Stenophylla also appears more tolerant of droughts, potentially capable of growing with less rainfall than arabica.
Robusta coffee can grow in similar conditions to stenophylla, but the price paid to farmers is roughly half that of arabica. Stenophylla coffee makes it possible to grow a superior tasting coffee in much warmer climates. And while stenophylla trees tend to produce less fruit than arabica, they still yield enough to be commercially viable.
The stenophylla harvest on Reunion Island. IRD / CIRAD, Author provided
To breed the coffee crop plants of the future, we need species with great flavour and high heat tolerance. Crossbreeding stenophylla with arabica or robusta could make both more resilient to climate change, and even improve their taste, particularly in the latter.
With stenophylla's rediscovery, the future of coffee just got a little brighter.
Aaron P Davis: Senior Research Leader, Plant Resources, Royal Botanic Gardens, Kew
Disclosure statement: Aaron P Davis receives funding from Darwin Initiative (UK).
Reposted with permission from The Conversation.
On Thursday, April 22, the world will celebrate Earth Day, the largest non-religious holiday on the globe.
This Earth Day falls at a critical turning point. It is the second Earth Day since the start of the coronavirus pandemic and follows a year of devastating climate disasters, such as the wildfires that scorched California and the hurricanes that battered Central America. But the day's organizers still have hope, and they have chosen a theme to match.
"At the heart of Earth Day's 2021 theme, Restore Our Earth, is optimism, a critically needed sentiment in a world ravaged by both climate change and the pandemic," EarthDay.org president Kathleen Rogers told USA TODAY.
Last Earth Day marked the first time that the holiday was celebrated digitally to prevent the spread of COVID-19. This will largely be the case this year as well.
"Most of our Earth Day events will be virtual with the exception of individual and small group cleanups through our 'Great Global Cleanup' program," EarthDay.org's Olivia Altman told USA TODAY.
Tuesday, April 20: A Global Youth Summit begins at 2:30 p.m. ET featuring young climate activists like Greta Thunberg and Alexandria Villaseñor. This will be followed at 7 p.m. ET by "We Shall Breathe," a virtual summit organized by the Hip Hop Caucus to look at issues like the climate crisis, pollution and the pandemic through an environmental justice lens.
Wednesday, April 22: Beginning at 7 a.m. ET, Education International will lead the "Teach for the Planet: Global Education Summit." Talks will be offered in multiple languages and across multiple time zones to emphasize the importance of education in fighting the climate crisis.
Thursday, April 22: On the day itself, EarthDay.org will host its second ever Earth Day Live digital event beginning at 12 p.m. ET. This event will feature discussions, performances and workshops focusing on the day's theme of restoring our Earth through natural solutions, technological innovations and new ideas.
"EARTHDAY.ORG looks forward to contributing to the success of this historic climate summit and making active progress to Restore Our Earth," Rogers said in a press release. "We must see every country rapidly raise their ambition across all climate issues — and that must include climate education which would lead to a green jobs-ready workforce, a green consumer movement, and an educated and civically engaged citizenry around the world."
EarthDay.org grew out of the first Earth Day in 1970, which drew 20 million U.S. residents to call for greater environmental protections. The movement has been credited with helping to establish the U.S. Environmental Protection Agency and to pass landmark environmental legislation like the Clean Air and Water Acts. It has since gone on to be a banner day for environmental action, such as the signing of the Paris agreement in 2016. More than one billion people in more than 192 countries celebrate Earth Day each year.
This legacy continues. The organization called the scheduling of Biden's summit a "clear acknowledgement of the power of Earth Day."
"This is a critical stepping stone for the U.S. to rejoin the world in combating the climate crisis. In concert with several planned parallel EARTHDAY.ORG events worldwide, Earth Day 2021 will accelerate global action on climate change," EarthDay.org wrote.
Super-emitters are individual sources such as leaking pipelines, landfills or dairy farms that produce a disproportionate amount of planet-warming emissions, especially methane and carbon dioxide. Carbon Mapper, the non-profit leading the effort, hopes to provide a more targeted guide to reducing emissions by launching special satellites that hunt for sources of climate pollution.
"What we've learned is that decision support systems that focus just at the level of nation states, or countries, are necessary but not sufficient. We really need to get down to the scale of individual facilities, and even individual pieces of equipment, if we're going to have an impact across civil society," Riley Duren, Carbon Mapper CEO and University of Arizona researcher, told BBC News. "Super-emitters are often intermittent but they are also disproportionately responsible for the total emissions. That suggests low-hanging fruit, because if you can identify and fix them you can get a big bang for your buck."
The new project, announced Thursday, is a partnership between multiple entities, including Carbon Mapper, the state of California, NASA's Jet Propulsion Laboratory (JPL) and Planet, a company that designs, builds and launches satellites, according to a press release. The project is being implemented in three stages.
The initial stage, which is already complete, involved the initial engineering development. NASA and Planet will work together in the second stage to build two satellites for a 2023 launch. The third phase will launch an entire constellation of satellites starting in 2025.
The satellites will include an imaging spectrometer built by NASA's JPL, NASA explained in a press release. This is a device that can break down visible light into hundreds of colors, providing a unique signature for chemicals such as methane and carbon dioxide. Most imaging spectrometers currently in orbit have larger pixel sizes, making it difficult to locate emission sources that are not always visible from the ground. However, Carbon Mapper spectrometers will have pixels of around 98 square feet, facilitating more detailed pin-pointing.
"This technology enables researchers to identify, study and quantify the strong gas emission sources," JPL Scientist Charles Miller said in the press release.
Once the data is collected, Carbon Mapper will make it available to industry and government actors via an open data portal to help repair leaks.
"These home-grown satellites are a game-changer," California Governor Gavin Newsom said of the project. "They provide California with a powerful, state-of-the-art tool to help us slash emissions of the super-pollutant methane — within our own borders and around the world. That's exactly the kind of dynamic, forward-thinking solution we need now to address the existential crisis of climate change."
By Jenna McGuire
Commonly used herbicides across the U.S. contain highly toxic undisclosed "inert" ingredients that are lethal to bumblebees, according to a new study published Friday in the Journal of Applied Ecology.
The study reviewed several herbicide products and found that most contained glyphosate, an ingredient best recognized from Roundup products and the most widely used herbicide in the U.S. and worldwide.
While the devastating impacts of glyphosate on bee populations are more broadly recognized, the toxicity levels of inert ingredients are less understood because they are not subjected to the same mandatory testing by the U.S. Environmental Protection Agency (EPA).
"Pesticides are manufactured and sold as formulations that contain a mixture of compounds, including one or more active ingredients and, potentially, many inert ingredients," explained the Center for Food Safety in a statement. "The inert ingredients are added to pesticides to aid in mixing and to enhance the products' ability to stick to plant leaves, among other purposes."
The study found that these inert substances can be highly toxic and even block bees' breathing capacity, essentially causing them to drown. While researchers found that some of the combinations of inert ingredients had no negative impacts on the bees, one of the herbicide formulations killed 96% of the bees within 24 hours.
According to the abstract of the study:
Bees exhibited 94% mortality with Roundup® Ready‐To‐Use® and 30% mortality with Roundup® ProActive®, over 24 hr. Weedol® did not cause significant mortality, demonstrating that the active ingredient, glyphosate, is not the cause of the mortality. The 96% mortality caused by Roundup® No Glyphosate supports this conclusion.
"This important new study exposes a fatal flaw in how pesticide products are regulated here in the U.S.," said Jess Tyler, a staff scientist at the Center for Biological Diversity. "Now the question is, will the Biden administration fix this problem, or will it allow the EPA to continue its past practice of ignoring the real-world harms of pesticides?"
According to the Center for Food Safety, there are currently 1,102 registered formulations that contain the active ingredient glyphosate, each with a proprietary mixture of inert ingredients. In 2017, the group filed a legal petition calling for the EPA to force companies to provide safety data on pesticide formulations that include inert ingredients.
"The EPA must begin requiring tests of every pesticide formulation for bee toxicity, divulge the identity of 'secret' formulation additives so scientists can study them, and prohibit application of Roundup herbicides to flowering plants when bees might be present and killed," said Bill Freese, science director at the Center for Food Safety. "Our legal petition gave the EPA a blueprint for acting on this issue of whole formulations. Now they need to take that blueprint and turn it into action, before it's too late for pollinators."
ATTN @EPA: Undisclosed "inert" ingredients in #pesticide products warrant further scrutiny! ➡️ A new study compared… https://t.co/bdFwXCVHsD— Center 4 Food Safety (@Center 4 Food Safety)1618592343.0
Roundup — also linked to cancer in humans — was originally produced by agrochemical giant Monsanto, which was acquired by the German pharmaceutical and biotech company Bayer in 2018.
The merger of the two companies was condemned by environmentalists and food safety groups who warned it would cultivate the greatest purveyor of genetically modified seeds and toxic pesticides in the world.
Reposted with permission from Common Dreams.