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Highlights from Duke in Australia

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.

Post by Sophie Cox, Class of 2025

Helping People and Wildlife Coexist in Ways That Benefit Both, Using Math

Duke team wins top prize in mathematical modeling contest


Safari-goers watch a pride of lions in the Maasai Mara, a famous game reserve in Kenya. Credit: Ray in Manila, CC BY 2.0 via Wikimedia Commons
Safari-goers watch a pride of lions in the Maasai Mara, a famous game reserve in Kenya. Credit: Ray in Manila, CC BY 2.0 via Wikimedia Commons

Of all the math competitions for college students, the annual Mathematical Contest in Modeling (MCM) is one of the biggest. And this year, Duke’s team took home a coveted top prize.

Undergraduates Erik Novak, ’24, Nicolas Salazar, ’23, and Enzo Moraes Mescall, ’24, represented the Blue Devils at this year’s contest, a grueling 4-day event where teams of undergraduates use their mathematical modeling skills to solve a real-world problem. The results are finally in, and the Duke team was chosen as one of the top 22 outstanding winners out of more than 11,200 teams worldwide.

Their task: to analyze some of the challenges facing a nature reserve in Kenya known as the Maasai Mara. This region is named for the local Maasai people, a tribe of semi-nomadic people who make a living by herding cattle. It’s also teeming with wildlife. Each year, more than a million wildebeests, zebras and gazelles travel in a loop from neighboring Tanzania into Kenya’s Maasai Mara Reserve and back, following the seasonal rains in search of fresh grass to eat.

Some 300,000 safari-goers also flock to the area to witness the massive migration, making it a major player in Kenya’s billion-dollar tourism industry. But protecting and managing the land for the benefit of both wildlife and people is a delicate balancing act.

The reserve relies on tourism revenue to protect the animals that live there. If tourism slumps — due to political unrest in Kenya, or the COVID-19 pandemic — desperate communities living around the park resort to poaching to get by, threatening the very wildlife that tourism depends on.

Poachers aren’t the only problem: wild animals such as lions, leopards and elephants sometimes venture into human settlements in search of food. Conservationists must strike a balance between protecting these animals and managing the dangers they pose by raiding crops or killing valuable domestic livestock.

Tourism is a mixed blessing, too. While safari-goers bring money into the region, they can also disturb the animals and pollute the Mara River, and off-road drivers can erode the soil with their jeeps.

The mission facing the Duke team was to identify ways to mitigate such conflicts between wildlife and people.

From left: Teammates Erik Novak, ’24, Nicolas Salazar, ’23, and Enzo Moraes Mescall ’24 finished in the top 0.1% in the 2023 Mathematical Contest in Modeling.

This year’s contest ran over a single weekend in February. Camped out on the third floor of Perkins library, the team of three worked 12 hours a day, fueled by a steady supply of Red Bull and poke bowls. During that time, they built a model, came up with budget and policy recommendations, and wrote a 25-page report for the Kenyan Tourism and Wildlife Committee, all in less than 96 hours.

They built a mathematical model consisting of a system of six ordinary differential equations. According to the model’s predictions, they said, it should theoretically be possible to increase the reserve’s animal populations by about 25%, reduce environmental degradation by 20%, nearly eliminate retaliatory lion killings, and cut poaching rates in half — all while increasing the average yearly flow of tourists by 7.5%.

Participating in a smaller-but-similar contest last fall, the Triangle Competition in Mathematical Modeling, helped them prepare. “It’s kind of like a practice for the MCM,” Salazar said.

Veronica Ciocanel

“They did not win that contest, but they took everything they learned and look what they did with it. I’m very proud,” said assistant professor of mathematics and biology Veronica Ciocanel, who coached the team and co-organized the Triangle competition.

In addition to finishing in the top 0.1% of competitors, the Duke team got three additional awards for their performance; the Mathematical Association of America (MAA) award, the Society for Industrial and Applied Mathematics (SIAM) prize, and an International COMAP Scholarship Award of $10,000.

The problems in these contests tend to be much more open-ended than typical coursework. “We didn’t know what the solution was supposed to be or what tools to use,” Novak said.

Modeling, computation and coding skills are certainly important, Ciocanel said. “But really what matters more is practice, teamwork, and communicating their results in a written report. Students who have a solid course background don’t need to do anything else to prepare, they just need to be creative about using what they know from the courses they already took.”

“Use what you have and work well together,” Ciocanel said. “That I think is the most important thing.”

Robin Smith
By Robin Smith

Meet Some of the Teams at the Bass Connections Showcase

If you weren’t outside enjoying the sun on Wednesday, April 19, you were probably milling around Penn Pavilion, a can of LaCroix in hand, taking in the buzz and excited chatter of students presenting at the 2023 Fortin Foundation Bass Connections Showcase.

Open floor presentations at the 2023 Bass Connections Showcase

This annual celebration of Bass Connections research projects featured more than 40 interdisciplinary teams made up of Duke faculty, graduate students, undergraduate students, and even partners from other research institutions.

Research teams presented posters and lightning talks on their findings. You might have heard from students aiming to increase representation of women in philosophy; or perhaps you chatted with teams researching physiotherapy in Uganda or building earthquake warning systems in Nepal. Below, meet three such teams representing a wide variety of academic disciplines at Duke.

Building sustainable university-community partnerships

As Bass Connections team member Joey Rauch described, “this is a poster about all of these other posters.” Rauch, who was presenting on behalf of his team, Equitable University-Community Research Partnerships, is a senior double-majoring in Public Policy and Dance. His interest in non-profit work led him to get involved in the team’s research, which aims to offer a framework for ethical and effective university-community research collaboration – exactly what teams do in Bass Connections. The group looked at complicated factors that can make equitable relationships difficult, such as university incentive structures, power dynamics along racial, socioeconomic, and ethnic lines, and rigid research processes.

Senior Joey Rauch with his team’s 2nd-place poster!

Along the lines of rigid research, when asked about what his favorite part of Bass Connections has been, Rauch remarked that “research is oddly formal, so having a guiding hand through it” was helpful. Bass Connections offers an instructive, inclusive way for people to get involved in research, whether for the first or fourth time. He also said that working with so many people from a variety of departments of Duke gave him “such a wealth of experience” as he looks to his future beyond Duke.

For more information about the team, including a full list of all team members, click here.

Ensuring post-radiation wellness for women

From left to right: seniors Danica Schwartz, Shernice Martin, Kayle Park, and Michelle Huang

Seniors Michelle Huang, Shernice Martin, Kayle Park, and Danica Schwartz (all pictured) were gathered around the poster for their team, Promoting Sexual Function and Pelvic Health in Women’s Healthcare.

The project has been around for three years and this year’s study, which looked at improving female sexual wellness after pelvic radiation procedures, was in fact a sister study to a study done two years prior on reducing anxiety surrounding pelvic exams.

As Huang described, graduate students and faculty conducted in-depth interviews with patients to better understand their lived experiences. This will help the team develop interventions to help women after life events that affect their pelvic and sexual health, such as childbirth or cancer treatment. These interventions are grounded in the biopsychosocial model of pain, which highlights the links between emotional distress, cognition, and pain processing.

For more information about the team, including a full list of all team members, click here.

From dolphins to humans

Sophomores Noelle Fuchs and Jack Nowacek were manning an interactive research display for their team, Learning from Whales: Oxygen, Ecosystems and Human Health. At the center of their research question is the condition of hypoxia, which occurs when tissues are deprived of an adequate oxygen supply.

Sophomores Noelle Fuchs and Jack Nowacek

Hypoxia is implicated in a host of human diseases, such as heart attack, stroke, COVID-19, and cancer. But it is also one of the default settings for deep-diving whales, who have developed a tolerance for hypoxia as they dive into the ocean for hours while foraging.

The project, which has been around for four years, has two sub-teams. Fuchs, an Environmental Science and Policy major, was on the side of the team genetically mapping deep-diving pilot whales, beaked whales, and offshore bottlenose dolphins off the coast of Cape Hatteras  to identify causal genetic variants for hypoxia tolerance within specific genes. Nowacek, a Biology and Statistics double-major, was on the other side of the research, analyzing tissue biopsies of these three cetaceans to conduct experiences on hypoxia pathways.  

The team has compiled a closer, more interactive look into their research on their website.

And when asked about her experience being on this team and doing this research, Fuchs remarked that Bass Connections has been a  “great way to dip my toe into research and figure out what I do and don’t want to do,” moving forward at Duke and beyond.

For more information about the team, including a full list of all team members, click here.

Post by Meghna Datta, Class of 2023

A Naturalist’s View of “Extraordinary” North Carolina

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.”

Post by Sophie Cox, Class of 2025

The Brain Science of Tiny Birds With Amazing Memories

A black-capped chickadee. Dmitriy Aronov, Ph.D., brought wild black-capped chickadees into the lab to study their memories.
Black-Capped Chickadee” by USFWS Mountain Prairie is licensed under CC BY 2.0.

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.

Post by Sophie Cox, Class of 2025

Spongy Moss, Living Jelly, and Other Early Spring Delights

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.

A representation of the evolutionary history of plants. Lycophytes, including the superficially grass-like quillwort we saw, are in the pteridophyte group, along with ferns. True grasses, on the other hand, are monocots, a branch of flowering plants.
Plant phylogeny.png, from Maulucioni via Wikimedia Commons, is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
By Sophie Cox

Post by Sophie Cox, Class of 2025

Warning: Birding Can Change You. Let It.

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, I have several, 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.

Photo of a male evening grosbeak.
Evening Grosbeak” by sedge23 is licensed under CC BY 2.0.

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.

Warbler illustrations by James Ellsworth De Kay, a zoologist who described hundreds of animal species in the 19th century. From top to bottom: black-throated blue warbler, Cape May warbler, and Nashville warbler.
131. The Black-throated Blue Warbler (Sylvicola canadensis) 132. He Cape-May Warbler (Sylvicola maritima) 133. The Nashville Warbler (Syvicola ruficapilla) illustration from Zoology of New york (1842 – 1844) by James Ellsworth De Kay (1792-1851).” by Free Public Domain Illustrations by rawpixel is licensed under CC BY 2.0.

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.

Post by Sophie Cox, Class of 2025

Recovery, Resilience, and Coexistence: Nature-based Solutions on the Coast

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.”

Post by Sophie Cox, Class of 2025

On-Stage Neuroscience with Cockroach Brains …and Legs

A low buzzing erupts into a loud static noise that fills the Duke lecture hall.

University of Michigan neuroscientist Gregory Gage describes the noise as the “most beautiful sound in the world.” It’s not the sound itself that evokes such fascination, but the source: this is the sound of electrical signals coming from neurons inside an amputated cockroach leg. 

With a background in electrical engineering, Gage credits this sound as the moment that got him interested in neuroscience. He now travels the country as an educator to bring his experiments to the public and encourage interest in neuroscience. His organization, Backyard Brains aims to bring research outside of the lab, and make it accessible to children and students everywhere. On Feb. 2, he presented the Gastronauts Seminar in the Nanaline Duke Building.

His first on-stage experiment aims to understand how information is encoded inside neurons, specifically the neurons located inside the barbs on cockroach legs. In order to record the signals without the roach running off, the first step is to amputate the cockroach leg. For all those worried for the well-being of the roach, rest assured that it was first “anesthetized” in a bath of ice water. (It’s still up for debate if cockroaches can truly feel pain, but Gage likes to err on the side of caution). Importantly, cockroaches also have the ability to regenerate limbs. In about five weeks a new leg will start to grow to replace the one that has been lost, and the entire regrowth will be completed in about 3 to 5 months. 

Underneath each hair on the leg of a cockroach, there is a neuron that detects stimuli and sends electrical impulses up to the brain.

The second step is to place electrode pins through the legs. Two pins are required so that the current will flow through the leg. One pin is located where there are very few neurons, serving as the ‘ground.” This experiment will measure the difference between the two pins, multiplied by the gain provided by an amplifier which makes the signal easier to see and hear. 

Turning up a volume knob on the amplifier, a low static buzzing becomes audible throughout the lecture hall. As Gage is the first to admit, “it doesn’t sound like much” at first. There are a few possibilities: maybe there is no neuron activity, maybe the leg is dead, or maybe it’s just not stimulated. The leg barbs contain stretch receptors: important sensory structures that play critical roles in detecting vibration, pressure, and touch.

These receptors are a type of ion channel, which are proteins located in the plasma membrane of cells that form a passageway through the membrane. They have the ability to open and close in response to chemical or mechanical signals. Stretch-activated ion channels respond to membrane deformation. When compressed, they allow ions to flow through, creating an immediate change in the transmembrane gradient and allowing for a rapid signaling response. The flow of ions is a flow of charge, and constitutes an electric current.

The opening and closing of ion channels underlie all electrical signaling of nerves and muscles. Why has the nervous system evolved to use electricity (as opposed to a chemical diffusion process)? Because it’s fast. And often our lives (or that of a cockroach) depend on responding quickly.

At the direction of Gage, a volunteer lightly brushes the cockroach leg. Suddenly, a change in the noise: short static bursts in volume correspond with each stroke of the cockroach leg. These are “single-unit recordings,” a sampling of the activity of individual or small clusters of neurons. The sound we are hearing is a burst of activity: the neurons rapidly firing in response to the stimuli, and attempting to send the electrical message up the brain.

Dr. Gage points out the spikes, or action potentials, associated with the firing of neurons in the roach’s leg.

Next, Gage pulls up his screen and shows a visual representation of the electrical signals. Along with the sound, it is clear to see the large spikes that correspond with the neurons firing. These spikes are called action potentials, and they occur when the membrane potential of a specific cell location rapidly rises and falls. When touching the leg hairs with more pressure, the number of action potentials per second increases. Measuring the number of spikes that occur per second is called rate coding, and it can be used to answer complex questions about how neurons respond to stimuli.

This experiment demonstrated how neurons send electrical impulses to the brain. But the brain does not just receive electrical impulses, it also sends them out. What happens if we tried to simulate the electrical impulses sent by the brain to the cockroach’s leg? In his second on-stage experiment, Gage demonstrates exactly this, using hip-hop music from his iPod as his electrical current.

The buds of a pair of headphones are cut off and replaced with small clips that attach to the electrode pins sticking out of the leg. Dr. Gage presses play on the music on his iPod, and immediately, the end of the cockroach leg begins to twitch and jump. The leg moves most dramatically with the bass of the music: lower frequencies have the longest waves, which correspond to the largest amount of current. 

You can watch Dr. Gage perform the “cockroach beatbox” experiment live on stage in one of his Ted Talks.

One final experiment combines both of the previous ones: how nerves encode information, and how nerves can be stimulated. A group of undergraduates at the University of Chile developed a system that uses an app to control the mind of a roach. Cockroaches use their antennae to observe the environment around them. If you take a cockroach and fit a wire inside each antenna (think of them like hollow tubes filled with neurons), you can stimulate those neurons, tricking the cockroach brain into thinking it has detected an outside stimulus. Using an Arduino microcontroller, the team of students created a little “hat” for the cockroach, and connected it via bluetooth to a smartphone app that can be used to send electrical impulses. Stimulating the right antennae causes the cockroach to move to the left, and stimulating the left antennae causes the cockroach to move to the right.

The RoboRoach device uses a smartphone app to perform “mind control” on the roach.

Why a cockroach? It’s a question that a volunteer stops to ask after finding herself up close and personal with the creature. Gage explains that they actually have brains very similar to our own. If we can learn “a little about how their brain works, we’re gonna learn a lot about ours.”

He ends his presentation with a parting message to all the researchers in the room: “I spend my life working on weird things like this, because each one tells a little story. Through these stories we can bring experiments to classrooms, democratize science and make it more accessible to everyone.”

Post by Kyla Hunter

Post by Kyla Hunter, Class of 2023

Some Primates Are More Susceptible to Parasites Than Others. Researchers Are Using New Methods to Find Out Why.

Chimpanzees are among the best studied primates for parasite interactions. Photo credit: Wikimedia Commons

Fleas, tapeworms, Giardia, pinworms:  Parasites are all around us. But some animals are more susceptible than others. Take the well-studied chimpanzee, for example: it’s known to host over 100 parasites. In contrast, species like the indri, a lemur only found on Madagascar, are only known to host about 10 parasites. Many other primates are so poorly studied that only one parasite has ever been recorded.

Relative to the chimpanzee, the indri is poorly known for its parasites. Credit: James Herrera.

In a new study published in the Journal of Animal Ecology, we examined which traits of both primates and parasites predict the likelihood of their interactions. Using advanced techniques in social network analysis, called the exponential random graph, we were able to simultaneously test the traits of primates and parasites to determine what predisposes primates to infection and what gives some parasites a unique advantage.

For primates, larger species that are found in warmer, wetter climates are more likely to host diverse parasites, compared to smaller species living in drier, cooler climates. Further, species in the same branches of the evolutionary tree and those that live in the same geographic region are more likely to share parasites than more distantly related species found on different continents. Viruses, protozoa, and helminth worms are more likely to infect diverse primates than fungi, arthropods, and bacteria. Parasites that are known to infect non-primate mammals are also more likely to infect diverse primates.

A photo from a microscope slide showing the blood parasite Plasmodium falciparum. One of the pathogens that causes malaria, P. falciparum also infects 118 other primates. In contrast, there are at least 30 other kinds of Plasmodium that only infect one or a few primates and their disease effects are poorly understood. Photo credit: Wikimedia Commons.

These new results were made possible by the great advances being made in infectious disease ecology. Over the last two decades, Dr. Charles Nunn at Duke University’s Evolutionary Anthropology and Global Health departments has been working with teams of researchers to compile all published records of primate-parasite interactions. Combing through the literature, almost 600 published sources were obtained to glean which parasites are found in over 200 primates species, with over 2,300 interactions recorded. With the analytical tools in social network science mastered by Duke Sociology professor Dr. James Moody, we were able to systematically test how traits of both hosts and parasites affect the likelihood of their interaction for the first time. While many previous studies used subsets of this database and examined either hosts or parasites in isolation, we were able to make new inferences about the critical links in this unique ecological network.

This work builds on a recent study that showed how extinction of primate hosts could lead to the co-extinction of almost 200 parasite species. While at first this might seem like a good thing, in fact it could have negative impacts on biodiversity as a whole. Many parasites don’t actually cause disease or death in the hosts, and some may even have beneficial properties. We simply don’t know enough about these critical and co-evolved relationships to understand what effects host-parasite coextinctions could have in the long-term.

While it might seem strange to worry about parasite extinctions, they are actually an important part of biodiversity and ecosystem functions. Understanding how primates and parasites interact reveals new insights into coevolutionary theory, and could also contribute to the conservation of underappreciated species richness. While from a public health perspective, we’d like to see some parasites disappear, like corona and ebola viruses, from an evolutionary stance, the sheer diversity of parasites and their intimate relationships with their hosts make them fascinating and crucial components of biodiversity.

By James Herrera, Ph.D., Duke Lemur Center SAVA Conservation Initiative

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