Rachel Carson was a twentieth-century marine scientist, conservationist, and writer. She is the author of Silent Spring, a groundbreaking book about the dangers of DDT and other pesticides. Photo courtesy of the Rachel Carson Council.
Robert K. Musil, Ph.D., M.P.H., recently visited Duke to talk about Rachel Carson’s environmental legacy and its implications for North Carolina today. Musil is the president and CEO of the Rachel Carson Council, an environmental organization founded in 1965 by friends and colleagues of Rachel Carson — a twentieth-century marine scientist, conservationist, and writer — after her death.
Robert K. Musil, Ph.D., M.P.H., president and CEO of the Rachel Carson Council. Photo courtesy of Musil.
Musil began his presentation with a stirring quote by Carson: “The more clearly we can focus our attention on the wonders and realities of the universe about us the less taste we shall have for the destruction of our race. Wonder and humility are wholesome emotions, and they do not exist side by side with a lust for destruction.”
Rachel Carson is famous for writing Silent Spring, a groundbreaking book warning of the dangers of DDT and other pesticides. Carson published Silent Spring in 1962. She died in 1964. In 1972, the United States banned DDT.
More than half a century later, in our world of climate crisis and biodiversity loss, Carson’s devotion to the natural world is still incredibly timely.
Rachel Carson’s Silent Spring documented how the insecticide DDT was harming not just insects but also animals farther up the food chain, human health, and the environment as a whole. The book spent thirty-one weeks on the New York Times bestseller list. Image courtesy of the Rachel Carson Council.
Carson, Musil says, “believed that you had to develop real empathy for other creatures, other beings, other people, other nations… that unless you loved it, you would destroy it.” In Carson’s first book, Under the Sea-Wind, she takes the perspective of animals like the black skimmer, the mackerel, and the eel. Carson was writing about the perils facing marine ecosystems, but she was doing it “from the point of view of the ‘other,’” as Musil puts it, focusing our attention on creatures other than ourselves.
“With the dusk a strange bird came to the island from its nesting grounds on the outer banks. Its wings were pure black, and from tip to tip their spread was more than the length of a man’s arm. It flew steadily and without haste across the sound, its progress as measured and as meaningful as that of the shadows which little by little were dulling the bright water path. The bird was called Rynchops, the black skimmer.”
-A passage from Under the Sea-Wind by Rachel Carson. Rynchops, Carson’s name for the black skimmer, comes from the bird’s genus name.
Musil describes how Carson would lie on the beach and hear crabs scratching the sand and listen to birds and imagine “how this life came to be, how these creatures, incredibly unique, came to this place in evolution.”
Carson was a marine scientist well before she published Silent Spring. She attended graduate school in marine biology with a full fellowship to Johns Hopkins University. At the same time, Musil says, she was working as a research assistant, teaching part-time at the University of Maryland and Johns Hopkins, and caring for extended family. Afterward, she worked for the Department of Fish and Wildlife and eventually became an author. Under the Sea-Wind was her first book; she wrote Silent Spring two decades later.
Carson is credited with spurring the modern environmental movement. Silent Spring and the concerns Carson raised about DDT prompted the President’s Science Advisory Committee, under the orders of John F. Kennedy, to investigate its dangers. Ultimately, DDT was banned in the United States, though Carson didn’t live to see it.
An “iconic photo” by Shirley Briggs of Rachel Carson on Hawk Mountain. Photo courtesy of the Rachel Carson Council.
But Musil emphasizes that throughout all Carson’s accomplishments, she did not act alone. He shows an “iconic photo,” as he describes it, of Rachel Carson sitting on Hawk Mountain and looking off into the distance through binoculars. The same photo is on the cover of Musil’s bookRachel Carson and Her Sisters: Extraordinary Women Who Have Shaped America’s Environment. He looks at the audience and asks a question: “Is Rachel alone on top of the mountain?” In the photo, Carson seems to be alone in a great expanse of wilderness, but the obvious answer to Musil’s question is no. Someone, after all, had to be there to take the picture.
That someone was Shirley Briggs, a friend of Carson’s and a scientist in her own right. “Rachel Carson,” Musil emphasizes, “was not alone.” Friends, colleagues, and mentors worked alongside her. And many of those people continued her work after she was gone. Before Carson died, Musil says, she asked Shirley Briggs and others to form an organization to carry on her work. The Rachel Carson Council was founded the following year. Nearly six decades later, the Council is still committed to “Carson’s ecological ethic that combines scientific concern for the environment and human health with a sense of wonder and reverence for all forms of life in order to build a more sustainable, just, and peaceful future,” according to a statement on their website.
According to Musil, North Carolina was one of Carson’s favorite places. After she had a breast cancer operation, he says, “she took refuge at Nags Head and walked its beaches.” The Rachel Carson Reserve commemorates Carson and preserves coastal habitats and wildlife. Musil believes that Carson’s legacy has broader environmental implications as well. One pressing issue in North Carolina today is Concentrated Animal Feeding Operations, or CAFOs, where many animals are raised in confinement. North Carolina produces ten billion gallons of hog waste from CAFOs each year—enough to fill 1500 Olympic swimming pools, according to Musil.
This is an ecological and animal welfare issue but also an environmental justice case. CAFOs are more often built near lower income and minority communities, and the waste from CAFOs can negatively affect human health, pollute waterways, and lead to fish kills and other ecological problems. Living near CAFOs is associated with higher rates of asthma and other health conditions, according to Musil. He acknowledged Francesca Cetta in the audience, who along with Lucy Goldman, both Duke Stanback Fellows at the Rachel Carson Council, did the research and writing on the Rachel Carson Council report, Swine and Suffering: An Introduction to the Hidden Harms of Factory Farms.
Environmental justice was not a term Carson used, but she had similar concerns about who was most affected by environmental issues. In Silent Spring, Musil says, Carson wrote about farmers who dealt directly with DDT and how unjust that was. Today, environmental justice is gaining momentum as organizations and governments wrestle with fairness and equality in the environmental sphere.
In spite of ongoing environmental degradation, Musil remains hopeful. “I have incredible hope for the future,” he says, because of his organization and its mentoring of future generations of environmentalists. “It’s not like every single person has to go out and go birdwatching — though I would recommend it,” he says, but he does believe it is important to learn about and appreciate the natural world and to recognize how it intersects with, for instance, capitalism and social justice. “Designing a much more equitable, greener society is critical,” he says, and when it comes to working toward that future, he is “never going to stop.”
He references the photo he showed earlier of Carson on the mountain: “I like to think instead of looking at hawks, she’s looking across those ridges and seeing… ranks and ranks of young people from Duke and across the country carrying on her vision.”
Duke in Australia 2023 in front of 1.9-billion-year-old stone in the Northern Territory. Photo by one of our tour guides.
Australia. For years it was more of a nebulous concept to me than a concrete place. It was a colorful patch on maps, home to animals I’d read about but never seen. Now it’s a place where I’ve run my hands over 1.9-billion-year-old stone, watched a platypus emerge from a river at dawn, gotten bitten on the tongue by an ant with a tasty green butt (long story), and spent a thousand other moments with wonderful people in places I hope to never forget.
That’s all thanks to Duke in Australia, a month-long biogeography course led by Alex Glass, Ph.D., and Nancy Lauer, Ph.D., that delves into Australian flora, fauna, geology, history, and culture. When people ask about my experience there this summer, I have a hard time answering. “Wonderful” doesn’t begin to cover it. The experience still doesn’t feel entirely real to me. Even when I was in Australia, watching a platypus or a parrot or standing on a beach with a sunrise on one side and a rainbow on the other, I sometimes couldn’t entirely believe where I was.
Sunrise at Myall Beach on Cape Tribulation, where the Daintree Rainforest meets the Great Barrier Reef.
Disclaimer: When I say “Highlights from Duke in Australia,” I’m referring to my own personal highlights—some of which, let me assure you, were not universally popular with my classmates. Like the enormous crickets we saw on our rainforest night hike, or the time I found the shed skin of a huntsman spider and went around showing it to everyone nearby, or the delightfully squelchy mud coating the trail on one of our last hikes. For more detailed accounts of our day-to-day activities, check out the student blogs on the Duke in Australia 2023 website.
From the moment we landed in Sydney, I was keeping my eyes peeled for bird sightings. (I am slightly into birds. Just slightly.) Unless you count an ambiguous white flash seen through a bus window, my first bird sighting in Australia was a small group of rainbow lorikeets flying over the city. With a blue head and stomach, a green back, an orange-red breast, and flashes of yellow under the wings, the species is very well named.
Lorikeets weren’t the only birds we saw in Sydney. Common mynas, which always looked vaguely sinister to me, watched us while we ate dinner the first night. Pigeons strutted along the sidewalks—the only bird species I saw in Australia that I’d also seen in the US, except a possible peregrine falcon that I caught only a brief glimpse of during a hike. There were also Australian ibises all over the city, colloquially known as bin chickens for their dumpster-diving habits. Personally, I thought the ibises were lovely, regal birds.
There are other birds, however, that can no longer call Sydney home. One of my favorite sites in Sydney was the Forgotten Songs art installation at Angel Place. It is a short alley engraved with the names of fifty bird species that can no longer survive in the city. Empty bird cages hang suspended above the street. Our tour guide told us that the exhibit normally plays recordings of the birds, but that part was under renovation, so it was playing music instead. A few days later, I returned to the exhibit on my own so I’d have time to read every bird name. Those empty cages still haunt me.
An eleven-armed seastar in one of the tide pools at Bondi Beach. (Eleven-armed seastars do not always have eleven arms.) Below it, you can see Neptune’s necklace, a type of algae resembling strings of beads.
On our first full day in Sydney, we went to Bondi Beach to explore the tidepools. There were crabs and octopi, seastars and anemones, necklace-like algae and tiny blue snails called little blue periwinkles. That afternoon, we sat on the beach and learned about microplastics from Lauer. (Not-so-fun fact: we eat a credit card’s worth of microplastics every week on average.) Some of us lingered on the beach afterward and went swimming. The water was frigid, but it was there, with cold water and sand swirling around me in a part of the ocean I’d never seen, much less swum in, that the reality of being on a new continent completely hit me.
Sunshine wattle flowers on our hike at North Head, viewed through a hand lens.
Our first group hike was overwhelming, almost dizzying. Outside of urban Sydney, it was easier for me to recognize just how different Australia was from the US, and it was impossible to absorb everything at once. In every direction were unfamiliar plants and landscapes. Norfolk pine, coastal rosemary, mountain devil, sunshine wattle, Darwinia, flannel flower, gray spider flower…. I was especially entranced by casuarina, which looks shockingly like a pine tree but is actually a flowering plant that has evolved conifer-like traits to preserve water. We were in a heath, characterized by low-growing plants adapted to dry, nutrient-poor conditions. Nothing about it looked like the woods and fields and mountains back home.
Our focus that day was studying plants, but I was having a hard time focusing on any one thing for more than about a second. At one point, we were supposed to be observing a beautiful plant to my right, but half the group had already moved on to another species farther up the trail, and meanwhile, a bird I had certainly never seen in my life was perched remarkably cooperatively on a bush off to the left. There are too many things happening, I remember thinking. I was juggling my field notebook, hand lens, phone camera, and binoculars, and I didn’t even know where to look. I chose to stare at the bird, following the logic that it could fly away at any moment, whereas the plants would stay exactly where they were. That brilliant plan turned out to be faulty. The plants might stay still, but we wouldn’t—so much to see, so little time.
A galah, a species of cockatoo, in Katoomba.
Our next stop was Katoomba, a small mountain town in New South Wales. It was a quiet, peaceful place, vastly different from Sydney. When I think of Katoomba, I think of the sulfur-crested cockatoo perched on a bakery sign just feet away from me and the flock of strikingly pink cockatoos called galahs in a local park. I think of the superb lyrebird that crossed our path directly in front of us and the rare Wollemi pine growing beside a road.
We took a hike at Wentworth Falls, where Darwin himself once walked. It’s part of the Great Dividing Range, but we learned that the mountains are actually “incised terrain,” formed when valleys were cut into a plateau, leaving “mountains” behind. We also drove to the Jenolan Caves and explored cavernous underground spaces bursting with crystal formations like stalactites, flowstone, and hollow soda straws. These lovely, fragile cave structures, or speleothems, are formed by the gradual deposition of dissolved minerals as water drips through a cave. Before we left, we saw an underground river with water so clear that I didn’t immediately realize I was looking at water at all.
Part of the Jenolan Caves. Gradual geologic processes form decorative structures, or speleothems, in caves.
Another day in Katoomba, our group took a gorgeous hike through a eucalypt forest. Literally everywhere I looked in that forest, there was something extraordinary. Ancient tree ferns. Ruby-red sap seeping out of a tree trunk. The Three Sisters rock formation framed by the aptly named Blue Mountains. Towering eucalypt and turpentine trees. At the end of the hike, we rode the Scenic Railway, the steepest in the world. It was terrifying—awesome, but terrifying.
A view from one of our hikes in the Blue Mountains.
Next, we flew to the Northern Territory, where we checked into our hostel in Darwin. We were now in crocodile country, home to the world’s largest reptile: the saltwater or estuarine crocodile. We were instructed to avoid going in any body of water, saltwater or otherwise, unless it was specifically designated as safe for swimming. (The name “saltwater crocodile” is misleading—the crocodiles can inhabit fresh water as well, and they are extremely aggressive and dangerous.) It was very important to be crocwise.
A rainbow bee-eater at the George Brown Darwin Botanic Gardens in Darwin, a city in the Northern Territory.
The first few days in Darwin, we didn’t see any crocodiles, but there were birds seemingly everywhere. Varied triller, which I originally misidentified as the buff-sided robin until a local eBird reviewer emailed me and asked me to correct my eBird report. Rainbow bee-eater, remarkably common for a bird that looks too beautiful to be real. Peaceful dove. Blue-faced honeyeater. Australasian figbird.
We took a hike that went through a beautiful mangrove, where we learned that the term mangrove isn’t specific to any particular type of plant; it’s used to refer to many very different species that have all adapted to the same challenges, including salinity, changing tides, and nutrient-poor soil. There were crabs and snails and birds—so many birds, some of which I still haven’t identified, like the group of black, crested birds with bright red inside their beaks.
Green weaver ants. Note their distinctive green abdomens, which contain ascorbic acid and have an interesting taste.
When we emerged from the mangrove, we came across a nest of green weaver ants. Their bright green abdomens are rich in ascorbic acid, and the ants have traditionally been used for purposes ranging from treating colds to making a sort of “lemonade” to stimulating milk production. Many of us were eager to taste the ants, though Glass warned us that they “bite vigorously.” Some of my classmates carefully held an ant with their fingers while giving the abdomen a quick lick. I, on the other hand, decided to let an ant crawl onto my notebook while I licked it so it couldn’t bite my fingers. Clever, right? Well, it worked—the ant didn’t bite my fingers. It bit my tongue instead. “Vigorously.” Its mouthparts remained latched on even as I was spitting out ant parts onto the ground. I can’t blame it—I’d be upset, too, if a giant tried to lick me.
Before long, it was time for the jumping crocodile tour. We boarded a tour boat and floated down a seemingly peaceful river while our guide dangled hunks of meat from big fishing rods to bait the crocodiles to leap several feet out of the water and snap their jaws around the food. Their bite force, incidentally, is the highest of any living animal, up to 3700 pounds per square inch. Jumping is natural for the crocodiles—they hunt that way to snag animals like birds and wallabies that venture too close to the water. Being that close to enormous predators roused some deep, primeval fear in me. To a crocodile, I would make excellent prey. The jumping crocodile tour, needless to say, was very memorable. Our class later had a long and far-ranging discussion on the many types of ecotourism experiences we’d participated in and their costs, benefits, and ethical implications.
One of the crocodiles on the jumping crocodile tour.
The next day, we left for a three-day camping trip in Kakadu and Litchfield National Parks. It was the dry season, and the weather was hot, dry, and sunny. We went hiking and snorkeling (in croc-free swimming holes), saw the breathtaking magnetic and cathedral termite mounds, and learned about geology and Aboriginal cultures. Some of the places we visited were sacred sites of the people who have inhabited the region for more than 65,000 years. One of the rock art paintings we were able to see was of a Tasmanian tiger, an animal that’s been completely extinct for close to a century and extinct in the Kakadu region for thousands of years. But right there on the wall was the preserved memory of a time when Tasmanian tigers still roamed the area.
Me with a stick insect at our campground in Kakadu National Park in Australia’s Northern Territory. Photo by Letar Jia, another student in the Duke in Australia program this summer.
One of the coolest places we stopped was a rock cut-out along a highway. The stone was striped with zigzagging layers created when it was buried underground at a pressure high enough to fold solid rock. It was formed 1.9 billion years ago, when the earth was “a geologist’s dream,” according to Glass–relatively barren, with no soil, plants, or animals, just microscopic organisms and lots and lots of rock. I was touching 1.9 billion years of history.
We spent the third night at a different campsite. Some of us spotted what seemed to be a large spider in the bathroom, but one of the tour guides informed me that it was actually just the shed skin of a huntsman spider, not the spider itself. I walked around camp introducing people to my “little friend,” but oddly enough, they didn’t seem as delighted as I was.
That night, while we were theoretically sleeping, periodic cacophonies of eerie, wailing screams reverberated through the air. My half-asleep brain was convinced they were from wallabies, but the sound actually came from a bird called the bush stone-curlew or bush thick-knee. The next morning, there was a gecko in the bathroom, and I wasn’t sure my day could possibly get any better. But later that day, we visited a fragment of an ancient rainforest, and there were giant fruit bats practically dripping from the canopy and giant golden orb weaver spider webs strung between trees, and I think that was even better than the bathroom gecko.
A female giant golden orb weaver, with my hand for scale. The tiny, orange spider on her back is the male.
After departing Darwin, we headed to Cape Tribulation, where the Great Barrier Reef meets the Daintree Rainforest—believed to be the oldest rainforest on the planet. Some rainforests, Glass explained, exist because they’re near the equator. But the rainforests in Australia are remnants of ancient rainforests that developed when the continents were arranged very differently and Australia was considerably farther south. Australia’s climate has become more arid over time, but pockets of its ancient rainforests remain intact.
While we were on Cape Tribulation, we had the chance to snorkel on the Great Barrier Reef. It was overcast and very windy that day, and the small boat that took us out to the reef turned into a rollercoaster as it slid up and down waves. But windy or not, the reef was gorgeous. We saw sea turtles, a sea cucumber, a small shark, and fishes and corals in endless colors.
We also had the incredible opportunity to hike through the rainforest at night. Of all the amazing things we did, that may have been my favorite. There were huge crickets and spiders, thorny vines called wait-a-whiles (because you’ll be waiting a while if you get stuck on one), and flowering plants that looked like mushrooms. And partway along the boardwalk, Glass spotted a creature so unusual and elusive that he had never seen one before. This, he told us, was probably the rarest animal we’d seen on the whole trip. A velvet worm. It looked a bit like a caterpillar or a centipede at first glance, but velvet worms have an entire phylum all their own. (Caterpillars and centipedes share the Arthropoda phylum, along with all insects, spiders, crustaceans, and various others. Velvet worms are in the Onychophora phylum.) The ancestors of velvet worms are thought to represent a link between arthropods and segmented worms. They are ancient, unique, and rarely seen.
The velvet worm.
Just moments later, Glass announced another incredible find: a peppermint stick. I raced ahead to see it. Earlier that day, I’d seen signs about peppermint stick insects, which excrete a peppermint-scented liquid as a defense mechanism, and I’d been keeping my eyes peeled ever since. The creature had developed a sort of mythical status in my mind; I’d been fantasizing about seeing one but hadn’t actually expected to. But there it was, right in front of us, large and stick-like, its color a blue-green so bright that it almost seemed to glow.
A platypus in a river in Yungaburra.
In Yungaburra, our next-to-last stop, we saw enormous fig trees and gorgeous waterfalls. On our last morning, several of us left the motel around dawn and walked to a nearby trail along a river in search of the platypus and the tree kangaroo, an arboreal kangaroo species. We found both. It was a fitting almost-ending to our trip. Both platypuses and kangaroos seem so iconically Australian. The platypuses slipped in and out of the water, their dark bodies visible even in the low light. The tree kangaroo watched us silently from its perch above us and then slowly began to move elsewhere.
A tree kangaroo in Yungaburra.
Before long, it was time to go home. We spent a couple days in Cairns first, where I saw a shiny, emerald green beetle and a tree positively full of squawking lorikeets. Even in the city, there were bright and beautiful animals. In places like the ones we visited, it is easy to find awe and wonder and beauty everywhere you look. But there are endless treasures here, too, fascinating and beautiful sights that we walk past every day, like the way spiderwebs turn silver in the sunlight, or the gray catbird that eats bright red magnolia fruits in the courtyard in front of my dorm window, or the tiny, bluish purple flowers on the Al Buehler Trail, soft and fuzzy and damp when I brushed my face against them. Duke in Australia was an unforgettable adventure. It was also a reminder to step out of the human bubble and immerse myself in the worlds of other living things—whether here or across the globe.
Clockwise: Jonathan Shaw, Adam Kosinski, Natalie Farris, and Kavya Menke looking at bryophytes on a log.
On a bright Sunday afternoon in April, I did something I had never done before. I went for a walk in the woods specifically to look for mosses. No, that’s not strictly true — we were looking for bryophytes. I learned, among other things, that not everything I had always called moss was really moss at all. (The word bryophyte comes from ancient Greek components and literally means “moss plant.”)
A patch of moss on the Al Buehler Trail. Moss is one type of bryophyte; liverworts and hornworts are the two others.
The walk was organized by Wild Ones, an undergraduate nature club I’m involved with. Biology Professor Jonathan Shaw, Ph.D., and Blanka Aguero, data and collections manager in the Duke University Herbarium, volunteered to teach a group of undergraduates about mosses and other bryophytes on the Al Buehler Trail adjacent to the Duke golf course.
Jonathan Shaw and members of the Wild Ones holding moss. Mosses, liverworts, and hornworts together represent the bryophytes.
Bryophytes (which include mosses, liverworts, and hornworts) represent one of several large groups of terrestrial plants. Other groups include angiosperms (flowering plants), gymnosperms (cone-producing plants like conifers and ginkgos), pteridophytes (vascular, spore-producing plants including ferns and horsetails), and lycophytes (an ancient group with about 1200 surviving members). According to Shaw, bryophytes are “the second biggest group after the flowering plants, but the flowering plants are an order of magnitude more diverse.” Aguero says that North Carolina has 462 moss species, 211 liverworts, and 7 hornworts.
Zach Pracher (Wild Ones member) and Blanka Aguero looking at bryophytes on a log.
Unlike the other terrestrial plant groups, bryophytes are nonvascular, meaning they lack the water transport tissues that other plants use. Without vascular tissue and without lignin for support, bryophytes can’t grow very big because they have no way to efficiently move water from their base to the rest of the plant. Instead, they grow close to the ground and absorb water directly from the environment into their cells.
Despite their preference for damp habitats, bryophytes can live for a long time without water. Some plants (like cacti) survive droughts by storing water, but bryophytes have a different strategy. They go into a state of dormancy, or suspended animation, and simply wait. Then, when it next rains, “they go hog-wild, photosynthesizing again in minutes,” Shaw says.
So if bryophytes don’t rely on constant moisture to survive, why do they like it so wet? Water, as it turns out, isn’t just important for hydration. Bryophytes rely on it to reproduce as well.
“Mosses are the amphibia of the plant communities,” Shaw says. Just as many amphibians can live on land but must return to the water to reproduce, bryophyte sperm has to “swim” to an egg cell to fertilize it. Therefore, they need water in order to reproduce, but they don’t need much. It could be mist from a splashing waterfall or a puddle in the woods or rainwater trickling down a tree. It could even be dew.
Moss on a tree trunk. Bryophytes can grow in a wide range of habitats across the world.
The day was warm and sunny, but the ground was dotted with puddles from recent storms. Armed with small hand lenses, we set off down the trail, stopping periodically to scrutinize tree bark, fallen logs, and thick patches of moss on the forest floor.
You need not travel far to find bryophytes. Mosses and their cousins colonize all sorts of hidden nooks: damp logs, trailside divots, tree bark, riverbanks, forgotten corners of backyards. Compared to seed-producing plants, bryophytes tend to have larger geographic ranges, perhaps in part because spores disperse more easily and because bryophytes can survive dry spells. Shaw estimates that about 75% of the moss species found in North Carolina are also found in Europe, and some of them are found in Asia as well.
Atrichum moss viewed through a hand lens. Note the thin line down the middle of each leaf. That line is a midrib and is one feature that sets mosses apart from liverworts.
We learned that most mosses have a midrib in the middle of each leaf, whereas liverworts have no midrib.
“A liverwort,” Shaw explains helpfully, “is like a moss, but it’s a liverwort.”
Liverworts are relatively flat in comparison to mosses because their leaves are in two parallel rows, whereas mosses tend to have a more spiral shape, with leaves emerging from all sides of the stem. The flat appearance of liverworts explains why they are sometimes called scale mosses. Another feature to consider if you’re trying to distinguish mosses and liverworts is the presence of lobed leaves, or leaves with protuberances off the main leaf (think of maple or oak leaves, for example). Some liverworts (but not all) have lobed leaves, but no mosses do.
A liverwort (main image) and the same liverwort viewed through a hand lens (top right). Liverworts and mosses can look very similar, but a hand lens makes it easier to spot the differences between them. Note the relatively flat appearance of the liverwort leaves compared to moss leaves, which tend to grow in a spiral fashion around the stem.
Aguero and Shaw both point out that the features we use to visually distinguish bryophytes aren’t necessarily the same features that officially set mosses and liverworts apart. The main difference between mosses and liverworts involves differences between their sporophytes.
Frullania is a genus of liverworts that forms dark patches, like the spots on this tree. If you see patches like these, Aguero says, they are “invariably” Frullania liverworts.
“It’s not true that if you’ve seen one moss, you’ve seen them all,” Shaw says. They’re small, yes, but they are not all the same.
We looked at one particularly lush patch of moss in the Bryoandersonia genus, named after a Duke professor. If you’re trying to identify trees, Shaw says, you might start with features like whether the leaves are broad or narrow and whether the tree is shrubby or not. With mosses, on the other hand, one of the first questions to ask is whether it’s pleurocarpous or acrocarpous. Pleurocarpous mosses, such as the Bryoandersonia we looked at, tend to have highly branching stems and grow in sprawling patches. The stems of acrocarpous mosses, meanwhile, have little or no branching and grow mostly vertically, often forming tight clumps.
Kavya Menke (Wild Ones member) examining a thallose liverwort we found by a stream.
After learning about patches of Frullania liverworts on trees from Aguero, we examined a large clump of liverworts growing beside a stream. Unlike the other liverworts we’d seen, this was a type of thallose liverwort, set apart from so-called leafy liverworts by the presence of thallus (a ribbon-like structure) instead of leaves. We also had the chance to smell it. Interestingly, liverworts also have a distinctive smell, sharp and earthy. The scent can be so strong that you might sometimes smell liverworts before you see them.
A thallose liverwort in the genus Conocephalum. Thallose liverworts are characterized by thalli (plural of thallus) instead of leaves. The other liverworts we saw were leafy liverworts. Photo by Adam Kosinski.
According to Shaw, the term liverwort dates back to when botany and herbal medicine were considered largely the same. The so-called Doctrine of Signatures is the long-held idea that plants’ physical features reveal their medicinal uses. Thallose liverworts were thought to resemble livers and were used to treat ailments of the liver, hence the name. Similarly, the walnut looks rather like a brain and was used to treat mental illness, while the Dutchman’s breeches flower (the white flowers are said to resemble pants) was used for sexually transmitted diseases.
Aguero says that some liverworts do contain chemicals with antimicrobial properties, but she advises people not to eat liverworts.
Moss sporophytes, which release spores into the air. (Top right: close-up through hand lens.) The sporophytes are the only part of a bryophyte that are diploid (containing two sets of chromosomes instead of one). The trees in the background are also diploid; most plants (with the exception of bryophytes) are diploid during most of their life cycle. Photos by Adam Kosinski.
Near the end of our walk, we found something we’d been keeping an eye out for but hadn’t yet seen: moss sporophytes. Bryophytes have a unique life cycle. Most of the time when we see a plant or an animal, it is diploid, meaning each cell contains two full sets of chromosomes (one from each parent). Every human cell, for instance, contains 46 chromosomes—with the exception of female egg and male sperm cells, which contain only 23. Cells that have only one set of chromosomes (like human egg and sperm cells) are called haploid. Plants undergo alternation of generations, meaning that one phase in their life cycle is haploid and one is diploid. In the case of most plants, the dominant and most conspicuous part of the life cycle is the diploid phase, but bryophytes are different. The fuzzy green carpets of moss we see are made of haploid cells, while the diploid phase is short-lived and only appears during reproduction. In mosses, the diploid phase (also known as the sporophyte) resembles thin filaments emerging from the haploid bed of moss. These sporophytes release spores (the spores are haploid) that grow into the next generation of moss.
“I wish we could be like the moss spores and let the wind carry us,” said Kavya Menke, one of the undergraduates on the walk. “Cheaper than Uber.”
Clockwise: Wild Ones members Natalie Farris, Adam Kosinski, and Zach Pracher examining patches of Frullania, a liverwort genus.
Occasionally, I paused my own bryophyte observations to watch others watching bryophytes. I found myself wondering if people are similarly bemused when they see me standing in a swamp with binoculars or crouching down on the way to class to move an earthworm off the sidewalk. I am accustomed to the world of birding, and looking for creatures like dragonflies, snakes, and salamanders feels natural to me as well. But this was a delightful opportunity to enter a world in which I had little to no experience: the shady, damp world of the bryophytes.
Adam Kosinski taking a close look at a bryophyte specimen placed on a log.
If you make a habit of going on walks with birders, you may spend a lot of time waking up before dawn, craning your neck upward, and straining to hear the alleged differences between a dozen kinds of short chirps. If you go out looking for snakes, you might spend a warm afternoon flipping over sun-warmed boards and scanning rocks and other basking spots. Searching for salamanders will likely involve scrutinizing wet soil, leaf litter, and ponds in early spring, possibly on a dark and rainy night. But searching for bryophytes is an experience all its own.
For one thing, you can go at any time of day and be equally successful, seeing as bryophytes neither crawl nor slither nor fly. You can also feel free to move as slowly as you wish. Aguero compares bryologists to lichenologists: “Moss people and lichen people work together frequently,” she says. “We walk similarly slowly.”
Blanka Aguero discussing bryophytes with students. Photo by Adam Kosinski.
You could walk the same trail a hundred times and see it a hundred different ways. You could focus on birds or earthworms or snakes, wildflowers or changing leaves, clouds or trees or rocks. The next time you are in the mood to explore a new world, consider taking a walk — either somewhere new or a path you’ve walked a hundred times before — and turning your attention to the wonderful world of the bryophytes. Pet the moss. Feel its springiness and dampness and softness. Run your fingers lightly over the thin sporophyte stalks and notice how they tickle your palm. Smell the liverworts. See the dark patches of Frullania on a tree trunk. Bryophytes are nearly everywhere. Look for them. Look at them. See them.
Bryoandersonia moss viewed through a hand lens. Photo by Adam Kosinski.
Naturalist Tom Earnhardt on Black River in North Carolina. The forests around Black River are home to the oldest trees in eastern North America, 2,700-year-old bald cypresses. All photos courtesy of Tom Earnhardt.
There are many ways to think of North Carolina. It was the 12th U.S. state to enter the Union. It is bordered by Virginia, Tennessee, Georgia, and South Carolina. North Carolina’s capital city is Raleigh, and it has an estimated population of 10,698,973. These are all facts, but they tell only part of the story: the human side of it.
Naturalist Tom Earnhardt offers other ways to view North Carolina: the state contains the oldest forest in the eastern United States, with trees up to 2,700 years old. It has 17 river basins, and some of its rivers show evidence of fishing weirs used by indigenous tribes hundreds of years ago. And from the Atlantic coast in the east to the Appalachian mountains in the west, North Carolina is home to thousands of native plants, animals, and fungi. There are 3,000 species of moths alone in North Carolina, and “Every one is essential; not one is optional.”
“North Carolina,” Earnhardt says, “is still one of the most biodiverse and extraordinary places on the planet.”
A prothonotary warbler. Prothonotary warblers inhabit swamps and coastal rivers in North Carolina. They are one of only two warblers in America that nest in cavities.
Earnhardt is a naturalist, photographer, writer, and attorney. He wrote and produced the show “Exploring North Carolina,” a series of dozens of episodes about North Carolina’s biodiversity, geography, and history. Earnhardt recently visited Duke to speak at the Nasher Museum of Art.
One inspiration for his talk was the ongoing Nasher exhibit “Spirit in the Land,” an exploration of ecology, culture, and connection to the natural world. “Art in its many forms,” Earnhardt says, “tells a story of love, loss, and renewal.”
Black River in North Carolina.
Earnhardt has spent much of his career balancing caution and hope. We are facing environmental crises, including climate change and biodiversity loss. Earnhardt believes it’s important for people to know that, but he has put a lot of thought into how to get that message across. Earnhardt has learned that it can help to “tell it as though it was your best friend or brother who needed to hear an important story.” Science alone isn’t always enough. “To hear bad news of any kind is not easy,” Earnhardt says, “and people want to hear it from people they know, people they trust or can relate to.”
The stories he tells aren’t always easy to hear, but they are important. We need to know — whether on a local, state, national, or international scale — what exactly we stand to lose if we continue on a path of environmental destruction. Many species are becoming more scarce, Earnhardt says, “but we still have them.” They can’t be protected once they’re gone, but many of them are still here and can still be preserved. The goal for all of us should be to keep it that way.
North Carolina, Earnhardt says, is at “the epicenter of the temperate world.” The state has a range of climates and habitats. It marks the northernmost native range of the American alligator, while coniferous forests in the North Carolina mountains resemble boreal forests of the northern U.S. and Canada. North Carolina, according to Earnhardt, contains “whole ecosystems that other states only dream about.”
Eastern North Carolina is characterized by beaches, salt marshes, and other coastal ecosystems. Here you can find “wildflowers that grow in salty sand” and painted buntings, multicolored songbirds unlike any other in North America. On four occasions, he’s even seen manatees in North Carolina.
A male painted bunting, a summer resident on North Carolina’s barrier islands. Female painted buntings are bright green.
“Travelers from around the world vacation here and raise their families in the summer,” Earnhardt says—and he’s not talking about humans. Many shorebirds and sea turtles lay their eggs on North Carolina’s beaches. Human disturbance, including artificial lighting and crowded beaches, can put their babies in danger. Minimizing light pollution near beaches, especially during turtle nesting season, and staying away from nesting shorebirds can help.
A longleaf pine savanna in southeastern North Carolina.
Moving farther west, we can find savannas of grasses and pine trees. “You drive past this, and people go, ‘ho hum, a pine barren.’” To that Earnhardt says, “Look a little closer.”
White-fringed orchids, one of North Carolina’s 80 native orchid species. Earnhardt took this photo in the Green Swamp, a longleaf pine savanna nature preserve.
These pine barrens are home to some of North Carolina’s 80 species of orchid, like the white-fringed and yellow-fringed orchids. “Look at them from all angles,” Earnhardt urges, “because from up above it becomes a sunburst… for those who watch.”
A yellow-fringed orchid, viewed from the side.
Be one of those who watches.
A yellow-fringed orchid, viewed from above.
North Carolina rivers, forests, and swamps are also home to many wildlife species. Forests around Black River contain “huge buttresses of tupelo that hold the world together” and bald cypresses that have been alive for 2,700 years. The early years of these now-ancient cypress trees coincided with the fall of the Assyrian Empire and the establishment of the first emperor of Japan. Many centuries later, they are the oldest trees in eastern North America.
Cypress trees on Black River. Both tupelos and cypresses have buttresses at their bases to provide stability in the water.
They are also in danger. “If seas rise three feet,” Earnhardt says, “there will be enough pressure to flood these [trees]…. We could lose them.” But “they are worth saving.”
Still farther west are the Appalachian mountains, another biodiversity hotspot. North Carolina is home to 60 species of salamanders, many of which live in the mountains. The southern Appalachians and western North Carolina contain more salamander diversity than anywhere else on the planet. One species that lives here is the American hellbender, a two-foot-long denizen of mountainous streams.
Despite increasing human development, North Carolina is still rich in flora and fauna. “We have wild places,” Earnhardt says. North Carolina has more than 450 bird species, over 30 native pitcher plants, 20 freshwater turtles, and 38 snakes—“and they’re all good neighbors,” Earnhardt adds.
Venus flytraps in a longleaf pine savanna.
North Carolina has pink and yellow lady slippers and ten-foot-tall Turk’s Cap lilies; crayfish and thousands of mushrooms; native azaleas and insects that depend on them. It has Earnhardt’s “new favorite bird,” the swallow-tailed kite, and vultures, “the clean-up crew: not optional.” That’s a refrain throughout Earnhardt’s talk. “Nothing I’ve shown you tonight is optional,” he says.
“Both in banking and nature,” Earnhardt says, “when we make too many withdrawals and not enough deposits… there’s a deficit.” There are too many creatures we have already lost. The eastern cougar. The Carolina parakeet. The passenger pigeon. Too many more. There are still others that are threatened or endangered but not yet gone. “We humans tend to forget the failures and close calls,” Earnhardt says. While talking about biodiversity loss, he references a quote by biologist E.O. Wilson: “This is the folly our descendants are least likely to forgive us.”
A swallow-tailed kite. Earnhardt says that these kites, which spend their winters in South America, now nest along several rivers in southeastern North Carolina.
So what can be done? To preserve biodiversity, we have to consider entire ecosystems, not just one endangered animal at a time. “We are part of the natural world, part of links and chains and pyramids,” Earnhardt says, and humans too often forget that. Everything is connected.
He recalls visiting entomologist Bill Reynolds’s lab and noticing crickets hopping across the floor. “Don’t step on the transmission fluid!” Reynolds warned. He was referring to the crickets and to insects more broadly. Like transmission fluid in cars, insects are essential to making sure the systems they are part of run smoothly. Insects serve crucial roles in food webs, pollination, and decomposition. Studies show that they are declining at alarming rates.
“We are at a crossroads,” Earnhardt says. “Our transmission fluid is low, and we have made too many withdrawals from the bank of biodiversity.” Still, he emphasizes the importance of not giving up on wildlife conservation. Given a chance, nature can and will regenerate.
Tupelo tree buttresses on Tar River near Greenville, North Carolina.
Despite all our past and current failures, conservation also has remarkable success stories. The brown pelican is one North Carolina resident that almost went extinct but has since “come back in incredible numbers.” The bald eagle is another. Its population plummeted in the 20th century, largely due to the insecticide DDT as well as habitat loss and hunting. By 2007, though, after intensive conservation efforts, it had rebounded enough to be removed from the endangered species list. Until about 1980, Earnhardt had never seen a bald eagle in North Carolina. Today, Earnhardt says, “I see them in every county.”
A bald eagle that Earnhardt saw near the Raleigh-Durham airport. Bald eagles, once on the brink of extinction, can now be seen in every county in North Carolina.
“Everyone’s going to have to fly in the same direction,” to preserve North Carolina — not to mention the rest of the world — at its best and wildest, Earnhardt says. But individual actions can make a difference. He suggests planting native flowers like milkweed and coneflower, both of which are good food sources for pollinators. And if you choose to plant ornamentals like crepe myrtle, “Treat that as a piece of art in the yard and then plant the rest as native.”
Lady Bird Johnson, a former first lady and conservation advocate, once said that “Texas should look like Texas, and Mississippi like Mississippi.” Choosing native plants can be a powerful way to help native wildlife in your own yard. “If you plant it,” Earnhardt says, “they will come.”
One audience member asks, “How do you recommend that we recruit non-believers?” It’s a conundrum that Earnhardt has put a lot of thought into. “It takes time, and it takes patience,” he says. “Some of my best friends are not full believers, but I work on them every day.”
Black-capped chickadees have an incredible ability to remember where they’ve cached food in their environments. They are also small, fast, and able to fly.
So how exactly can a neuroscientist interested in their memories conduct studies on their brains? Dmitriy Aronov, Ph.D., a neuroscientist at the Zuckerman Mind Brain Behavior Institute at Columbia University, visited Duke recently to talk about chickadee memory and the practicalities of studying wild birds in a lab.
Black-capped chickadees, like many other bird species, often store food in hiding places like tree crevices. This behavior is called caching, and the ability to hide food in dozens of places and then relocate it later represents an impressive feat of memory. “The bird doesn’t get to experience this event happening over and over again,” Aronov says. It must instantly form a memory while caching the food, a process that relies on episodic memory. Episodic memory involves recalling specific experiences from the past, and black-capped chickadees are “champions of episodic memory.”
They have to remember not just the location of cached food but also other features of each hiding place, and they often have only moments to memorize all that information before moving on. According to Aronov, individual birds are known to cache up to 5,000 food items per day! But how do they do it?
Chickadees, like humans, rely on the brain’s hippocampus to form episodic memories, and the hippocampus is considerably bigger in food-caching birds than in birds of similar size that aren’t known to cache food. Aronov and his team wanted to investigate how neural activity represents the formation and retrieval of episodic memories in black-capped chickadees.
Step one: find a creative way to study food-caching in a laboratory setting. Marissa Applegate, a graduate student in Aronov’s lab, helped design a caching arena “optimized for chickadee ergonomics,” Aronov says. The arenas included crevices covered by opaque flaps that the chickadees could open with their toes or beaks and cache food in. The chickadees didn’t need any special training to cache food in the arena, Aronov says. They naturally explore crevices and cache surplus food inside.
Once a flap closed over a piece of cached food (sunflower seeds), the bird could no longer see inside—but the floor of each crevice was transparent, and a camera aimed at the arena from below allowed scientists to see exactly where birds were caching seeds. Meanwhile, a microdrive attached to the birds’ tiny heads and connected to a cable enabled live monitoring of their brain activity, down to the scale of individual neurons.
An artistic rendering of one of the cache sites in an arena. “Arenas in my lab have between 64 and 128 of these sites,” Aronov says. Drawing by Julia Kuhl.
Through a series of experiments, Aronov and his team discovered that “the act of caching has a profound effect on hippocampal activity,” with some neurons becoming more active during caching and others being suppressed. About 35% percent of neurons that are active during caching are consistently either enhanced or suppressed during caching—regardless of which site a bird is visiting. But the remaining 65% of variance is site-specific: “every cache is represented by a unique pattern of this excess activity in the hippocampus,” a pattern that holds true even when two sites are just five centimeters apart—close enough for a bird to reach from one to another.
Chickadees could hide food in any of the sites for retrieval at a future time. The delay period between the caching phase (when chickadees could store surplus food in the cache sites) and the retrieval phase (when chickadees were placed back in the arena and allowed to retrieve food they had cached earlier) ranged from a few minutes to an hour. When a bird returned to a cache to retrieve food, the same barcode-like pattern of neural activity reappeared in its brain. That pattern “represents a particular experience in a bird’s life” that is then “reactivated” at a later time.
Aronov said that in addition to caching and retrieving food, birds often “check” caching sites, both before and after storing food in them. Of course, as soon as a bird opens one of the flaps, it can see whether or not there’s food inside. Therefore, measuring a bird’s brain activity after it has lifted a flap makes it impossible to tell whether any changes in brain activity when it checks a site are due to memory or just vision. So the researchers looked specifically at neural activity when the bird first touched a flap—before it had time to open it and see what was inside. That brain activity, as it turns out, starts changing hundreds of milliseconds before the bird can actually see the food, a finding that provides strong evidence for memory.
What about when the chickadees checked empty caches? Were they making a memory error, or were they intentionally checking an empty site—even knowing it was empty—for their own mysterious reasons? On a trial-by-trial basis, it’s impossible to know, but “statistically, we have to invoke memory in order to explain their behavior,” he said.
A single moment of caching, Aronov says, is enough to create a new, lasting, and site-specific pattern. The implications of that are amazing. Chickadees can store thousands of moments across thousands of locations and then retrieve those memories at will whenever they need extra food.
It’s still unclear how the retrieval process works. From Aronov’s study, we know that chickadees can reactivate site-specific brain activity patterns when they see one of their caches (even when they haven’t yet seen what’s inside). But let’s say a chickadee has stored a seed in the bark of a particular tree. Does it need to see that tree in order to remember its cache site there? Or can it be going about its business on the other side of the forest, suddenly decide that it’s hungry for a seed, and then visualize the location of its nearest cache without actually being there? Scientists aren’t sure.
Duke biology professor Paul Manos, Ph.D., looking at peat moss with Wild Ones members Gurnoor and Dhruv.
The Wild Ones club recently visited the Duke Forest with biology professor Paul Manos, Ph.D., and herpetology professor Ron Grunwald, Ph.D., to look for salamander eggs and other early spring delights.
It was warm and sunny, and wildflowers sprouted up alongside the trail, but most of the trees were still bare. “It’s kind of nice to look in a forest without any leaves,” says Manos. “They get in the way a lot.” We examined winged elm and shagbark hickory at the trailhead, then windflower and bluets right beside the path. Many early spring wildflowers take advantage of the higher levels of sunlight that reach the forest floor before trees develop leaves.
A shagbark hickory tree in the Duke Forest. “Shagbark” refers to the peeling strips on the trunk. The word “hickory,” meanwhile, comes from an Algonquin word for both the tree and a food made from pounded hickory nuts.
Manos was delighted to find a patch of sphagnum moss beside the trail. He says sphagnum, also known as peat moss, is usually found in higher latitudes, like the United Kingdom and Canada, where it grows in huge fields known as moorlands or quaking bogs.
When we reached a small pond, Grunwald swept a long-handled net through the water and leaf litter and pulled out a gelatinous glob that promptly became a highlight of my week/month/year: spotted salamander eggs. I don’t know what the rest of you spent your childhoods doing, but I spent a good portion of mine looking for frog eggs (and sometimes finding them) and wanting to find salamander eggs (and never finding them). But here they were, in front of me, tinted green with algae and glinting in the sunlight and close enough to touch.
Bluets are members of the coffee family, which Manos says is “known for having a lot of chemical diversity.” Many of the members of that family grow in the tropics, but some, like this bluet, live in more temperate regions.
This strikes me as an appropriate retort to many unrelated things. Calculus test? Yeah, okay, but I saw salamander eggs. The grosbeaks that Wild Ones went looking for two weeks ago are still thwarting me? Yes, and I still haven’t gotten over it. However: salamander eggs.
Sphagnum moss. It is wonderfully moist and spongy. Photo by Lydia Cox, one of the student leaders of Wild Ones.
The egg mass was less firm and less slimy than I expected. It felt remarkably similar to jelly. “This gel,” Manos says, “apparently doesn’t allow oxygen to move through it very well,” but the developing spotted salamander larvae need oxygen. The solution is ingenious: a partnership with green algae. A species of algae grows on the egg masses and penetrates individual eggs, and eggs with more algae grow and develop faster.
The algae are photosynthetic, creating carbon and oxygen products from carbon dioxide gas and sunlight. That process likely provides supplemental oxygen to the salamander embryos, and one study found that the salamanders also absorb carbon produced by the algae’s photosynthesis.
Herpetology professor Ron Grunwald with spotted salamander eggs.
That carbon fixation is the first known example of carbon transfer from algae to a vertebrate host, though similar partnerships have been found in invertebrates, and the authors of the study speculate that similar processes may be occurring in other amphibians as well.
The particular species of algae that grows on spotted salamander eggs is in the Oophila, which according to Manos means “egg lover.” The partnership, however, is temporary. “It’s a very short-lived, ephemeral story,” Manos says.
“This is the best day of my life,” says Michelle, a Wild Ones member, while holding spotted salamander eggs. Comments from other students included “This feels weird,” “That is a sublime experience,” and “Nature’s fidget.”
In addition to the spotted salamander eggs, Grunwald also found a marbled salamander larva. Marbled salamanders and spotted salamanders are in the same genus, but they have different approaches to breeding. Marbled salamanders, Grunwald explains, lay their eggs in the fall “where they think a pond is going to be” instead of waiting for ephemeral pools to develop in spring. How do they decide where to lay eggs if the pond isn’t even there yet? Scientists aren’t sure, but salamanders “live in a chemical world,” Grunwald says, relying on taste and chemical signals.
Spotted salamander eggs and a marbled salamander larva, temporarily held in a plastic bag for viewing purposes. Photo by Adam Kosinski, Wild Ones co-president.
Since marbled salamanders laid their eggs last fall, their larvae have had time to hatch and start developing, though they aren’t yet adults. Spotted salamanders, meanwhile, don’t breed until spring—when the ponds actually exist—so their eggs haven’t yet hatched. For the larvae of both species, developing in small, temporary ponds helps protect them from large predators like fish.
Both marbled and spotted salamanders are in a genus sometimes called mole salamanders because they live underground when they’re not breeding. “There’s an entire city underground here of burrows and holes and crevices,” Grunwald says, a “whole porous network of spaces.” The mole salamanders can shelter underground, but they can’t travel far without coming back to the surface. “It’s not a highway,” Grunwald says.
I would like to know what it is like to be a mole salamander, navigating by taste and smell and spending much of the year in small spaces underground.
Sam, a Wild Ones member, releasing the eggs back into the pond.
Before we left the forest, we went searching for lycophytes, an ancient lineage of plants that first evolved hundreds of millions of years ago. “In the Carboniferous Period 350 million years ago, these guys ruled,” Manos says. The lycophytes we saw in the Duke Forest were tiny, bright green sprigs in a small stream, but their ancestors were trees. Those ancient lycophyte trees are “responsible for all of the coal that we use,” says Manos. “The transformation of their organic material via millions of years of heat and pressure to metamorphic carbonized rock is the definition of coal.”
Quillwort, a modern-day descendant of ancient trees.
The lycophytes in the stream are members of the Isoetes genus, also known as quillworts. They look and feel much like grasses, but they are only distant relatives of true grasses. Grasses are flowering plants, while quillworts are lycophytes. Flowering plants and lycophytes diverged hundreds of millions of years ago. Lycophytes use spores to reproduce and have a life cycle similar to ferns. Even their leaves are anatomically and evolutionarily different from the leaves of flowering plants; lycophytes use “their own approach to making leaves,” according to Manos.
The Wild Ones, a student organization focused on enjoying and learning about nature, recently went to Flat River Waterfowl Compound to look for birds and my personal nemesis.
I have a nemesis (a bird that defies my searching). Actually, Ihaveseveral, but I have been preoccupied with this particular nemesis for months.
I have seen an evening grosbeak exactly once, in a zoo, which emphatically does not count. For years, I have been fixated on-and-off (mostly on) with the possibility of seeing one in the wild.
They have thick, conical beaks. The males are sunset-colored. (But good luck finding one at sunset, even though the first recorded sighting supposedly happened at twilight, hence their name.) I daydream about flocks of them descending on my bird feeders at home or wandering onto Duke’s campus. That hasn’t happened yet (unless it has happened while I have not been watching, an excruciating possibility I will simply have to live with).
Evening grosbeaks usually live in Canada and the northern U.S., but they are known to irrupt into areas farther south. Irruptions often occur in response to lower supplies of seeds and cones in a bird’s typical range, making it possible to predict bird irruptions, at least if you’re the famous finch forecaster. (Fun fact: “irrupt” literally means “break into,” whereas “erupt” means “break out.”)
Breaking news: The grosbeaks are in Durham, and they have been since December. I will wait while you perform any necessary reactions, including screaming, jumping up and down in delight, charging outside because you simply have to go find them right now, or telling me I must be mistaken.
I am not mistaken. There is a flock of evening grosbeaks overwintering at Flat River Impoundment, 11.8 miles from Duke University. I know this because I get hourly rare bird alerts by email, and I have been receiving emails about evening grosbeaks nearly every day for almost three months. Put another way, evening grosbeaks have been actively and no doubt intentionally taunting me for weeks on end.
Adam Kosinski, Wild Ones co-president, with binoculars.
Wild Ones, a student organization I’m involved with, had been thinking of organizing a birding trip. For reasons I will not even attempt to deny, I suggested Flat River Waterfowl Impoundment. Last Sunday, seven undergraduates drove there, armed with field guides and binoculars and visions of evening grosbeaks bursting into sight (okay, maybe that was just me).
Flat River Waterfowl Impoundment. Photo by Adam Kosinski.
The morning was chilly but sunny. Flat River is a gorgeous, swampy place full of small ponds and stretches of long grass edged with trees. As soon as we got there, we were serenaded with birdsong: the high, musical trill of pine warblers, the haunting coo of mourning doves, lilting Carolina wren songs, and squeaky-dog-toy brown-headed nuthatch calls.
Photo by Adam Kosinski.
It wasn’t long before people got to experience the frustrating side of birding. We were admiring a sparrow in a ditch, trying to guess its identity. Someone pulled out a field guide and flipped through the sparrow section only to turn back to the bird and find it gone. Birds can fly. But fortunately, we’d collectively noticed enough field marks to feel reasonably confident identifying it as a swamp sparrow.
A white-throated sparrow, one of several that was feeding on the buds of this tree. Note the white throat and yellow lores. Photo by Lydia Cox, Wild Ones member. (We are not related, if you’re wondering.)
We found two other sparrow species later: song sparrows and white-throated sparrows. Sparrows tend to be small, brownish, and streaky, but certain features can help distinguish some of the common species around here. I’m personally not very familiar with the swamp sparrow, but it has a rusty cap and gray face. The song sparrow has brown stripes on its head, extensive streaking on its underside, and a dark spot on its breast. The white-throated sparrow has striking black-and-white stripes on the top of its head, yellow lores on its face (the spot in front of the eye), and yes, a white throat. (Just don’t rely too much on bird names for identification. Red-bellied woodpeckers definitely have red heads but usually only have red bellies if you’re rather imaginative, but beware—they’re still red-bellied, not red-headed woodpeckers. Meanwhile, there are dozens of warblers with yellow on them, but only one of them is a yellow warbler. Nashville warblers only pass through Nashville during migration, and American robins aren’t robins at all.)
A Cooper’s hawk with prey between its talons. Note the gray wings, the red barring on the bird’s underside, the dark bands on its tail, and the red eye. Photo by Lydia Cox.
We saw Carolina chickadees flitting through trees, an Eastern phoebe doing its characteristic tail-wagging, and a Cooper’s hawk feeding on prey. Then, thrillingly, we spotted a bald eagle soaring through the sky. The bald eagle, America’s national bird since 1782, was in danger of extinction for years, largely due to the insecticide DDT, which made their eggs so thin that even being incubated by their parents could make them crack. However, the bald eagle was removed from the endangered species list in 2007, and populations have continued to increase.
A bald eagle in flight. Photo by Lydia Cox.
Not long after the eagle sighting, we saw another flying raptor: an osprey. In fact, it must have been a good day for raptors because by the end of our trip we had recorded one osprey, two Cooper’s hawks, three bald eagles, and two red-tailed hawks.
We also saw a lot of birders—perhaps two dozen others, maybe more, not counting our own group. Each time we passed a group going in the opposite direction, I asked them if they’d found the grosbeaks.
A bald eagle nest. Photo taken with my phone through my binoculars, a technique that is slowly teaching me a modicum of patience.
I think everyone I asked had seen them, and they were all eager to point us in the right direction. Birders like to use landmarks like “by the eagles’ nest” and “the fifth pine on the right” and “past the crossbills.” We found the eagles’ nest, with help from some of the local birders. We think we found the fifth pine on the right, but there were a lot of pines there, so we’re not sure.
We did not find the red crossbills, another irruptive bird species overwintering here this year. (Crossbills are aptly named. The tips of their mandibles really do cross, which helps them access seeds inside cones.)
Red crossbills, another irruptive bird species, have also been overwintering at Flat River Waterfowl Impoundment, but Wild Ones did not see them. “Red Crossbills (Male)” by Elaine R. Wilson, www.naturespicsonline.com is licensed under CC BY-SA 3.0.
We found the spot where the evening grosbeaks had most recently been seen — just twenty minutes before we got there, according to the people we were talking to. We waited. We scrutinized the pine trees. We watched red-tailed hawks and bald eagles circle high above us. We admired the eagles’ nest, a huge collection of sticks high in a pine tree.
Adam Kosinski and Abby Saks, making sure there were no birds hiding underwater. (They were actually looking at interesting water creatures like crayfish and tadpoles.)
Would you like to guess what we did not find? My nemesis. Because the evening grosbeaks have devious minds and clearly flew all the way to Durham with the sole intent of hiding from me, dodging me, flying away as soon as I approached, and flying back again as soon as I was gone. (No, really. Other people reported them at Flat River that same day, both before and after our trip there.)
From left: Ethan Rehder, Barron Brothers, Sophie Cox, Gurnoor Majhail (Wild Ones co-president), and Lydia Cox. Photo by Adam Kosinski.
Birding can be intensely frustrating. It can plant images in your mind that will haunt you and taunt you for the rest of your life. Like, for instance, the tiny blue bird I caught a brief glimpse of in the trees one early morning in Yellowstone. For years, I wondered if it could have been a cerulean warbler, but cerulean warblers don’t live in the western U.S. Or let’s talk about the green bird—yes, I swear it was green; no, I can’t prove it—that came to my bird feeders several years ago and never came back. Not while I was watching, anyway. The only thing I can think of for that one is a female painted bunting, but painted buntings aren’t usually in upstate South Carolina. (If my local volunteer eBird reviewer in South Carolina ever happens to read this, I promise I won’t report either of those mystery sightings to eBird.) Or, of course, the evening grosbeaks that flew away twenty minutes before we arrived.
Birding can also be thrilling, meditative, and by all accounts wonderful. Yes, that little blue bird in Yellowstone and the maybe-green one in my backyard are branded in my memory, as are countless more moments of maybe and almost and what if? I will never know what they were. I will probably never get over it.
But there are other moments that stick in my mind just as clearly. The bald eagle soaring above us on this Wild Ones trip. The black-capped chickadee that landed on my finger years ago while my brother and I rested our hands on a bird feeder and waited to see what would happen. My first glimpse of a black-throated blue warbler (I am so proud of whoever named that bird species), chasing an equally tiny Carolina chickadee in my backyard.
The Cape May warbler I saw with a close friend in a small field covered in purple wildflowers. The first time I heard the loud, ringing Teacher-teacher-teacher! song of the ovenbird. A blackpoll warbler, the first I’d ever seen, in a grove of trees in a swampy field that only birders seem to find reason to visit.
The moment two Carolina wrens took food from my hand for the first time. Prothonotary warblers (another nemesis bird) practically dripping from the trees on a rainy, buggy hike along a boardwalk. The downy woodpecker that landed on my gloved hand, apparently too impatient to wait for me to finish what I was doing with the suet feeder, and pecked at the suet with that sharp beak, her black tongue flicking in and out, her talons clinging to me with a trust that brought tears to my eyes.
Birding can change you. It can make your world come alive in a whole new way. It can make traveling somewhere new feel all the more magical — a new soundscape, new flashes of colors and patterns, a new set of beings that make a place what it is. In the same way, birding can make home feel all the more like home. Even when I can’t name all the birds that are making noise in my yard, there is a familiarity to their collective symphony, a comforting sense of “You are here.” I encourage you to watch and listen to birds, too, to join the quasi-cult that birding can be, to trek through somewhere wet and dark when the sky is just beginning to lighten—or to simply step outside, wherever you are, and listen and watch and wait right here and right now. You don’t even need to know their names (though once you start, good luck stopping). And you certainly don’t need a nemesis bird. In fact, your birding experience will be calmer without one. But that might not be up to you, in the end. Nemesis birds have minds of their own.
We live in a country where 80% of both Democrats and Republicans believe that the other political party “poses a threat that if not stopped will destroy America as we know it.” Lovely.
A 2020 study found that only 3.5% of voters would avoid voting for their preferred candidate if that candidate engaged in undemocratic behavior. In 2022, 72% of surveyed Republicans said that Democrats are more immoral than other Americans, and 83% of Democrats said that Republicans are more close-minded than other Americans. Political polarization is apparently increasing faster in the U.S. than in other democracies, but Americans aren’t just divided along political lines. Other aspects of identity, like religious beliefs, can spawn discord as well. In the U.S., 70% of atheists think religious organizations “do more harm than good,” but 44% of Americans still think that you must believe in God “in order to be moral and have good values.”
Most Americans agree that polarization is a problem. But what can be done about it? The Trent Center for Bioethics, Humanities, and History of Medicine recently hosted a conversation between two people who have spent much of their careers engaging with many different beliefs and perspectives. A recording of the talk can be found here.
Molly Worthen, Ph.D., Associate Professor of History at UNC and a freelance journalist, grew up in a “secular, totally nonreligious home,” but courses she took in college made her realize that “for a huge swath of humanity, over the course of our history,” religion has helped people find meaning and community. She has explored religion extensively through her work as a historian, author, and journalist. Worthen says she has “way too risk-averse a temperament to be a full-time journalist,” but one advantage of journalism is that it provides “an excuse to ask people questions.”
Emma Green, a journalist at The New Yorker, has also covered religion in her writing and spent time engaging with people and communities who hold a wide variety of beliefs. Green believes that “the most interesting stories are often about the debates communities are having within themselves.” These debates aren’t just about religion. In communities of all kinds, people with different and often opposing beliefs navigate disagreements with their best friends, neighbors, and family members as they engage with polarizing issues and try to find ways to coexist.
The process of interviewing people with differing worldviews and beliefs can bring challenges, but both Worthen and Green have found that those challenges are not insurmountable. “If you do your homework and you really make a good-faith effort to learn where a person is coming from,” Worthen says, “they will tell you their story. They will not shut down.”
Worthen has spent time with a community of Russian Orthodox Old Believers in Alberta. It was an opportunity to make a “concerted effort to really get inside the worldview of someone very different from myself.”
Green has also spent time talking to and learning from religious communities. She published an article about Hyattsville Mennonite Church in Pennsylvania, which had been welcoming gay members for over a decade and had originally been “disciplined” by the Allegheny Mennonite Conference for its open acceptance of homosexuality. A decade later, the Conference gathered to determine whether the Hyattsville church should be allowed to rejoin the Conference or be removed from it altogether. (A third option, according to Green’s article, was to dissolve the Conference.) Green was struck by how the Mennonite community approached the dispute. They followed the formal “Robert’s Rules of Order,” but they also sang together in four-part harmony. The central dispute, Green says, was “about whether they could stay in community with one another.” Ultimately, the gay members were allowed to stay, though Green says that some people left the congregation in protest.
Polarization is a word we hear a lot, but why is it that we seem to have such a hard time finding common ground when it comes to important—or even seemingly unimportant—issues? Worthen points out that there seems to be a new survey every few years showing that “humans are generally impervious to evidence” that goes against our existing beliefs.
“Barraging a human with evidence doesn’t really work,” Worthen says. According to her, theologians and philosophers have long said that “we are depraved, irrational creatures, and the social science has finally caught up with that.”
This hesitancy to even consider evidence that conflicts with our existing beliefs has implications on public trust in science. Too often, “believing in science” takes on political implications.
According to Pew Research Center, only 13% of Republicans have “a great deal” of confidence in scientists, compared to 43% of Democrats. “Many people on the left think of the universities as belonging to them,” says Worthen, leading to a greater sense of trust in science. “There is a desire on the left to want science to line up” with their political views, Green agrees, but good science isn’t inherently aligned with a particular political party. Science involves uncertainty and “iterative self-correction,” Worthen says, but even acknowledging uncertainty can spawn controversy. And when science doesn’t perfectly align with someone’s political or ideological beliefs, it can make people uncomfortable. For instance, Worthen believes that “the retreating date of viability” for fetuses and better fetal imaging technology is “provoking… discomfort on the left” in conversations about abortion.
Similarly, evidence from evolutionary biology can be hard to reconcile with deeply held religious beliefs. Worthen describes an interview she did with Dr. Nathaniel Jeanson. He has a Ph.D. from Harvard in cell and developmental biology, but he is also a Young Earth creationist who believes the earth was created by God in six days. There are “plenty of conservative Christians who understand those days as metaphors,” Worthen says, but Jeanson takes the six-day timeframe described in the Bible literally. In Worthen’s article, she says that Jeanson “dutifully studied evolutionary biology during the day and read creationist literature at night.” One thing Worthen admired in Jeanson was his willingness to be “honest about who we are”: not very open to new evidence.
“I think very few humans are anti-science,” Worthen says. “It’s more that humans are selectively pro-science.”
It isn’t just politics that can cause people to distrust science. Green points out that people who have had frustrating experiences with traditional healthcare may look for “other pathways to achieving a sense of control.” When patients know that something is wrong, and mainstream medicine fails them in some way, they may turn to alternative treatments. “That feeling of not being understood by the people who are supposed to know better than you is actually pretty common,” Green says, and it can fuel “selective distrust.”
It can be helpful, Worthen says, for a clinician to present themselves as someone trustworthy within a larger system that some patients view as “suspect.”
Distrust in public health authorities has been a recurring theme during the Covid pandemic. Green recalls interviewing an orthodox Jewish man in New York about his community’s experiences during the pandemic. Many Orthodox Jewish communities were hit hard by Covid, and Green believes it’s important to recognize that there were many factors involved. Even well-meaning health officials often lacked the language skills to speak dialects of Yiddish and other languages, and the absence of strong, pre-existing relationships with Orthodox communities made it harder to build trust in the middle of a crisis.
Worthen spoke about vaccine hesitancy. “For most of the population who has gotten the [Covid] vaccine,” she says, “it’s not because they understand the science but because they’re willing to ‘outsource’” their health decisions to public health authorities. It is “important not to lose sight of… how much this is about trust rather than understanding empirical facts.”
Finally, both speakers discussed the impacts of social media on polarization. According to Green, “information ecosystems can develop in social media and become self-contained.” While “there are a lot of people out there who are quacks who purport to be experts,” social media has also created public health “stars” who offer advice and knowledge to a social media audience. Even that, however, can have downsides. “There isn’t a lot of space for uncertainty, which is a huge part of science,” Green says.
Worthen, meanwhile, believes that “social media is one of the main assets destroying our civilization…. I would encourage everyone to delete your accounts.”
Polarization is pervasive, dangerous, and difficult to change. “As a journalist, I basically never have answers,” Green says, but maybe learning from journalists and their efforts to understand many different perspectives can at least help us begin to ask the right questions. Learning to actually listen to each other could be a good place to start.
How should we engage with books, songs, or other works of art created by artists, dead or alive, who have done bad things or hold morally problematic views?
J.K. Rowling, the author of the landmark Harry Potter series, has become controversial because of her 2020 tweets about transgender people.
It’s one thing to firmly condemn their actions and reject their beliefs. But what should we do with their art—as individuals and as institutions?
The Kenan Institute of Ethics recently held a conversation to discuss exactly that issue. The discussion was moderated by Jesse Summers, Ph.D., and featured speakers Erich Hatala Matthes, Ph.D., Associate Professor of Philosophy at Wellesley College and author of “Drawing the Line: what to do with the work of immoral artists from museums to the movies,” and Tom Rankin, Professor of the Practice of Art and Documentary Studies and Director of the MFA in Experimental and Documentary Arts at Duke University.
Why should we care about morality in art, anyway? Why not just appreciate the art and separate it from the artist?
Matthes believes that in some cases, “to not engage with the moral dimensions of a work would be to not take the work seriously.” He thinks Shakespeare’s works belong in this category. “Trickier cases,” he adds, “might come from works that aren’t explicitly engaged” with morality, but even in those cases, “the moral life of the artist can actually become a lens through which to read aspects of the work.”
Film director Woody Allen with his wife and former step-daughter Soon Yi Previn in 2009. (David Shankbone via Wikimedia Commons)
We already consider context when viewing art, not just “formal features of the work.” What was the artist responding to? What were the politics at the time? Matthes believes it makes sense to consider the “moral life” of the artist, too. That “doesn’t mean the artist’s moral life is always going to be relevant” to engaging with the art, but he thinks it’s worth at least acknowledging.
According to Rankin, “When we look at a piece of art or hear something, what we hope is that it propels us” to consider moral issues. How, he asks, can we not look at a painting or photo and wonder, “Where did this come from? Who made it? What was their agenda? What is their point of view? What was their background?”
So where does that leave us, Rankin asks, when it comes to “work that was made a hundred years ago but is really powerful… and yet when we look at it a hundred years later it has all kinds of flaws?” Should museums remove paintings by famous artists if racist or sexist views come to light? Should individuals boycott books, songs, and video games created (or inspired) by artists who have made harmful statements toward individuals or groups of people? How should college classes address works by immoral artists?
Matthes says the term “immoral artists” in his book is intentionally provocative. “I don’t actually think it’s productive” to think of people as good or bad, moral or immoral, he says. “There’s a huge range” in the morality or lack thereof in artists’ actions, and Matthes believes there should also be a range in our responses, but he doesn’t believe that “great art can ever just excuse immorality.” He wants to reject the idea that “artists need to be a little inhuman” and “outside the norms of society.” He thinks that mindset encourages us to think of artists as not subject to the same rules. They should not be “immune to moral criticism,” he says.
Rankin agrees: “I do balk a little bit at having to be the one to decide who’s bad and who’s good,” but at the same time, he believes that “artists make work in response to who they are.” So “What do we confront first? The life of the artist or the work itself? It’s not one or the other,” he says.
Both speakers believe that context is often key to interpreting and evaluating art. Matthes says that it might be “really obscene” to choose Michael Jackson music at your wedding if you know one of your guests has experienced child abuse, given the child sexual assault allegations against Jackson. However, Matthes doesn’t believe that completely “cancelling” Jackson’s music is the solution, either.
Similarly, Matthes doesn’t believe that “we should necessarily continue with big exhibitions honoring Paul Gauguin,” a painter who had sexual relationships with young girls and employed racist terminology. According to Matthes, Gauguin “represents a paternalistic energy of a particular time” that we should “interrogate.” As for the notion that we should extend a degree of lenience to historical artists and view them as a product of their times, Matthes is “disinclined” to think of morality as relative to time period. The time when a work of art was created might affect how we engage with it or assign blame, but “Gauguin did a lot of morally horrific things, and the fact that it was in a different time and place doesn’t change that.”
Nevertheless, Matthes thinks we can and should still engage with and respond to the work of “immoral artists.” His concern, he says, is that taking art off of walls and bookshelves and not talking about it “isn’t reckoning with the legacy.” He also doesn’t “see a reason to put certain types of art on a pedestal and treat them differently…. Artistic expression is a fundamental part of human life.”
What if an individual doesn’t want to engage with such art at all? What if the actions of an artist, dead or alive, are so objectionable to someone that they want nothing to do with it? Matthes is okay with that attitude, though he does think it’s “missing an opportunity.”
Completely disengaging from art on account of its creator’s moral life “feels like a way of not taking the moral criticism seriously,” Matthes says. “It’s not something you would be wrong to fail to do,” but he believes in engaging with moral issues, even those that “it would be easier to just ignore.”
Michael Jackson’s album Thriller sold 32 million copies in 1983.
But he acknowledges that personal identities can play a role in how or whether we engage with the work of immoral artists. Matthes believes it’s important to consider “the position you’re coming from” when you read or think about these issues. On the other hand, people and groups who may be more directly impacted by an artist’s problematic views “also have really thoughtful, nuanced ways” of engaging—or not engaging—with the art.
Matthes believes that “we have a lot of moral latitude when it comes to our individual engagement” with art. He finds it difficult to make the argument that reading, listening to, or viewing art in your own home is directly harmful to others, even if the artist in question is still alive.
Summers, meanwhile, points out that if someone is upset by an artist, there could be cases where “you’re taking it out on your friends… when you should be taking it out on the band.”
Institutions like universities, however, might need to take further considerations. “Different moral norms might apply,” Matthes suggests, “based on the positions of power we occupy.” Classrooms, for instance, are a “semi-public” space. They can help provide context in conversations about “morally problematic art” and encourage people to “think really carefully and critically.” If a class is going to engage with such topics, though, Matthes thinks it’s important to spell that out to students beforehand.
Powerful conversations can take place outside of classrooms, too — in book clubs and even informal conversations with friends. “You don’t want to let the moral concerns completely drive the bus” when engaging with art, Matthes says, “but I think it’s important not to ignore them.”
Rankin concludes by reminding us that it isn’t just artists who face decisions about how to respond to the world. For instance, even among those who don’t think of themselves as photographers, anyone who carries a cell phone is making choices every time they take a photo — about what they’re presenting and why.
When it comes to balancing the needs of humans and the needs of nature, “Historically it was ‘develop or conserve’ or ‘develop or restore,’” says Carter Smith, Ph.D., a Lecturing Fellow in the Division of Marine Science & Conservation who researches coastal restoration.
However, according to Brian Silliman, Ph.D., Rachel Carson Distinguished Professor of Marine Conservation Biology, “We are having a new paradigm shift where it’s not just… ‘nature over here’ and ‘humans over here.’”
Instead, conservation initiatives are increasingly focusing on coexistence with nature and ecological resilience, according to this panel discussion of marine science experts during Duke Research and Innovation Week 2023.
Nature-based solutions — protecting and restoring natural shoreline habitats — have a proven role in protecting and restoring coastal ecosystems. According to the International Union for Conservation of Nature (IUCN), “Nature-based solutions… address societal challenges effectively and adaptively, simultaneously benefiting people and nature.”
The panel, moderated by Andrew J. Read, Ph.D., Stephen A. Toth Distinguished Professor of Marine Biology and Professor of Marine Conservation Biology, also included Brian Silliman, Carter Smith, and Stephanie Valdez, a Ph.D. Student in Marine Science & Conservation.
Living shorelines can help protect coastal ecosystems from storms while also offering benefits for climate and conservation. Photos by Carter Smith.
According to Smith, nature-based solutions can “leverage nature and the power of healthy ecosystems to protect people” while also preserving biodiversity and mitigating climate change. She spoke about living shorelines as an effective and ecologically responsible way to protect coastal ecosystems.
“The traditional paradigm in coastal protection is that you build some kind of hard, fixed structure” like a seawall, Smith said, but conventional seawalls can have negative effects on biodiversity, habitats, nutrient cycling, and the environment at large. “In this case, coastal protection and biodiversity really are at odds.”
After multiple hurricanes, living shorelines had significantly less visible damage or erosion than sites with conventional hardscape protection, like seawalls.
Nicholas Lecturing Fellow Carter Smith
That’s where living shorelines come in. Living shorelines incorporate plants and natural materials like sand and rock to stabilize coastal areas and protect them from storms while also creating more natural habitats and minimizing environmental destruction. But “if these structures are actually going to replace conventional infrastructure,” Smith says, it’s important to show that they’re effective.
Smith and colleagues have studied how living shorelines fared during multiple hurricanes and have found that living shorelines had significantly less “visible damage or erosion” compared to sites with conventional storm protection infrastructure.
After Hurricane Matthew in 2016, for instance, both natural marshes and conventional infrastructure (like seawalls) lost elevation due to the storm. Living shorelines, on the other hand, experienced almost no change in elevation.
Smith is also investigating how living shorelines may support “community and psychosocial resilience” along with their benefits to biodiversity and climate. She envisions future community fishing days or birdwatching trips to bring people together, encourage environmental education, and foster a sense of place.
PhD student Stephanie Valdez then spoke about the importance of coastal ecosystems.
“Blue carbon ecosystems,” which include sea grasses, marshes, and mangroves, provide services like stabilizing sediments, reducing the destructive force of powerful waves, and storing carbon, she said. These ecosystems can bury carbon much faster than terrestrial ecosystems, which has important implications when it comes to climate change.
In the atmosphere, carbon dioxide and other greenhouse gasses contribute to global warming, but plants pull carbon dioxide out of the air during photosynthesis and convert it to carbohydrates, releasing oxygen as a byproduct. Therefore, ecosystems rich in fast-growing plants can serve as carbon sinks, reducing the amount of atmospheric carbon, Valdez explained.
Unfortunately, blue carbon ecosystems have suffered significant loss from human activities and development. We’ve replaced these wild areas with farms and buildings, polluted them with toxins and waste, and decimated habitats that so many other creatures rely on. But given the chance, these places can sometimes grow back. Valdez discussed a 2013 study which found that seagrass restoration led to a significantly higher carbon burial rate within just a few years.
Sea grasses, marshes, and mangroves provide services like stabilizing sediments, reducing the destructive force of powerful waves, and storing carbon.
PhD Student Stephanie Valde
Valdez also talked about the importance of recognizing and encouraging natural ecological partnerships within and between species. Humans have taken advantage of such partnerships before, she says. Consider the “Three Sisters:” beans, corn, and squash, which Native Americans planted close proximity so the three crops would benefit each other. Large squash leaves could provide shade to young seedlings, beans added nitrogen to the soil, and cornstalks served as a natural beanpole.
Recognizing that mutualistic relationships exist in natural ecosystems can help us preserve habitats like salt marshes. Valdez points to studies showing that the presence of oysters and clams can positively impact seagrasses and marshes. In restoration, it’s important “that we’re not focusing on one species alone but looking at the ecosystem as a whole”—from top predators to “foundation species.”
“There is hope for successful restoration of these vital ecosystems and their potential to aid in climate change mitigation,” Valdez said.
Finally, Prof. Brian Silliman discussed the role of predators in wider ecosystem restoration projects. Prioritizing the protection, restoration, and sometimes reintroduction of top predators isn’t always popular, but Silliman says predators play important roles in ecosystems around the world.
“One of the best examples we have of top predators facilitating ecosystems and climate change mitigation are tiger sharks in Australia,” he says. When the sharks are around, sea turtles eat fewer aquatic plants. “Not because [the sharks] eat a lot of sea turtles but because they scare them toward the shoreline,” reducing herbivory.
However, Silliman said it’s unclear sometimes whether the existence of a predator is actually responsible for a given benefit. Other times, though, experiments provide evidence that predators really are making a difference. Silliman referenced a study showing that sea otters can help protect plants, like seagrasses, in their habitats.
Restoring or reintroducing top predators in their natural habitats can help stabilize ecosystems impacted by climate change and other stressors.
And crucially, “Predators increase stress resistance.” When physical stressors reach a certain point in a given ecosystem, wildlife can rapidly decline. But wildlife that’s used to coexisting with a top predator may have a higher stress threshold. In our ever-changing world, the ability to adapt is as important as ever.
“I think there is great optimism and opportunity here,” Silliman says. The other speakers agree. “Right now,” Valdez says, “as far as restoration and protection goes, we are at the very beginnings. We’re just at the forefront of figuring out how to restore feasibly and at a level of success that makes it worth our time.”
Restoring or reintroducing top predators in their natural habitats can help stabilize ecosystems impacted by climate change and other stressors.
Brian Silliman
Smith emphasized the important role that nature-based solutions can play. Even in areas where we aren’t achieving the “full benefit of conserving or restoring a habitat,” we can still get “some benefit in areas where if we don’t use nature-based solutions,” conservation and restoration might not take place at all.
According to Valdez, “Previously we would see restoration or… conservation really at odds with academia itself as well as the community as a whole.” But we’re reaching a point where “People know what restoration is. People know what these habitats are. And I feel like twenty or thirty years ago that was not the case.” She sees “a lot of hope in what we are doing, a lot of hope in what is coming.”
“There’s so much that we can learn from nature… and these processes and functions that have evolved over millions and millions of years,” Smith adds. “The more we can learn to coexist and to integrate our society with thriving ecosystems, the better it will be for everyone.”
