The Incredible Journey of a Migratory Shorebird
On a sunny June morning, in a bog outside Beluga, Alaska, I met a Hudsonian godwit. She had inky eyes and a long, slightly upturned beak that was pinkish-orange at its base and brownish-black at its tip. The feathers on her back were of mottled sepia tones, and those on her belly were rusty brown and painterly white. Her legs reminded me of the slender inserts of spring-loaded ballpoint pens, and her feet were refined pterodactyl claws. Her name (among humans) was A34, and she was about the size of a city pigeon. She was in the hands of Nathan Senner, a conservation biologist, who removed and replaced her geotag; measured her head, beak, wing, and leg; weighed her; and took two tail feathers and a sample of her blood. From that small number of data points, he can deduce where she’s been, how her feathers have grown, what genetic subgroup she belongs to, and her degree of exposure to mercury.
Senner leads a research laboratory at the University of Massachusetts, Amherst, that is largely focussed on how migratory shorebirds, such as godwits, respond to environmental change. He grew up in Anchorage, where school loudspeakers announced the street corners on which moose had been sighted. In high school, he wrote an occasional “Birding with Nathan” column for the Anchorage Daily News. Senner’s father, Stanley, has devoted more than five decades to the conservation of migratory shorebirds. Starting in the nineteen-seventies, Stanley and his colleagues have been sounding the alarm on the vulnerability of shorebirds and working to protect key habitats, such as Alaska’s Copper River Delta. “Back then, no one was even talking about climate change,” he told me recently. Since 1980, roughly half of migratory shorebird species’ populations have declined by more than fifty per cent.
Migratory shorebirds are usually not a person’s first bird crush. They lack the supernatural aura of the resplendent quetzal, and they don’t go in for outlandish mating displays like that of the prairie chicken. As the Princeton University biology professor and shorebird-lover David Wilcove put it, migratory shorebirds can give an impression of being “little brown guys, buzzing around in the mud, not too big and not too small, and, whether one is a stint or a phalarope or a knot or a godwit, they’re just kind of there.” And yet, Wilcove told me, they are a birder’s kind of bird. Once people get to know them, they tend to fall in love.
Relatively few people have laid eyes on Hudsonian godwits. The birds mostly divide their time between remote northern bogs and muddy South American shores. John James Audubon apparently never saw a living one; he based his drawing of them in “Birds of America” on a few specimens he found in markets. Arthur Cleveland Bent, in a 1927 installment of his twenty-one-volume series, “Life Histories of North American Birds,” wrote of Hudsonian godwits, “I can count on the fingers of one hand the red-letter days when I have been privileged to see this rare and handsome wader.”
It’s entirely possible that I had encountered A34 two months before seeing her in Alaska. In March, I had travelled from New York to Chiloé Island, in Chilean Patagonia. Flocks of Hudsonian godwits (the smallest of the four godwit species and the least well known) spend from roughly early October to April in and around the tidal mudflats there. The island also has Humboldt penguins, giant rhubarb plants with leaves as large as umbrellas, and the world’s smallest species of deer. Castro, the main town, is famous for its brightly painted wooden seaside houses, which rest on tall stilts to accommodate the tide. Homo sapiens is a shore-loving species. About forty per cent of us live within sixty miles of a coast.
Chiloé is where Hudsonian godwits spend their non-breeding season and express their non-breeding personality, which is intensely gregarious and food-oriented. If you walk at low tide on the mudflats of Pullao Bay, you will see godwits bobbing for bivalves and worms, dunking their beaks in and out of the ground as if they were darning. They share their feasting grounds with oystercatchers, ducks, whimbrels, greater yellowlegs and lesser yellowlegs, and other shorebirds that neither I nor my Merlin Bird ID app could identify. The longer I watched the shorebirds on Chiloé Island, the stronger my impression was that they were dressed for a masquerade or a carnival, with some wearing stout beaks, some slim ones, others elegantly curved ones. The pale bellies and darker backs of many of the birds made it look as if they had on fashionable capes over slender, hosiery-clad legs. They called out to one another and occasionally broke into cotillion-like flight. The Hudsonian godwits appeared eternally committed to these revels. There was no sign that they were about to fly nearly ten thousand miles to Alaska, a wondrous and mystifying migration that one scientist called “technically impossible.”
Birds are in trouble. Migratory shorebirds are in especially bad trouble. And long-distance migratory shorebirds, like the Hudsonian godwit, may be in the most trouble. “Birds are sentinels,” Stanley Senner told me. “The ecosystems they rely on are ecosystems we rely on as well, though it can take time to convince people of that.” Studies show that, without shorebirds, coastlines erode more quickly, trap less carbon, and are more likely to become unbalanced. In the Yellow Sea, for example, shorebirds feed on crabs whose population needs to be kept in check, as they graze on native vegetation. In some ways, shorebirds are analogous to the wolves that hunt the deer and elk populations that eat the tree saplings that become the trees that beavers use to build dams that help the fish—and so on. Shorebirds also transport and disperse essential seeds and nutrients. Our interests align, as they say. Also, like all birds, they are lovable, alien, awesome, and alive. Not long ago, I saw a dead magpie on a country highway. Other magpies gathered around it, as if saddened and confused. When a car approached, they scattered. After the car passed, they returned to their fallen friend. So there’s also that.
To protect birds effectively, we need to understand them. So much about godwits remains unknown, including where and when they encounter their most mortal threats. Since their epic migration is maybe their most difficult-to-fathom characteristic, we may as well start there.
The story of bird migration, as narrated in Western civilization, often begins with Aristotle, who wrote that, in the winter, redstarts turn into robins and garden warblers turn into blackcaps. This sounds silly but, compared with the idea that a caterpillar becomes a butterfly, it seems reasonable. Olaus Magnus, a sixteenth-century Swedish priest, argued that barn swallows disappear in the fall because they hibernate at the bottom of ponds. That also seems absurd until you learn about the common poorwill, which resembles an old piece of bark and spends months of winter nestled almost imperceptibly in the crevices of logs or among piles of rocks. This wasn’t scientifically documented until 1948, although the poorwill has long been known to the Hopi as hölchoko, “the sleeping one.”
The Maori tell a story about how a godwit showed their ancestors the way from their ancient homeland of Hawaiki to New Zealand, more than a thousand miles away. But, to most people, avian migrations of that length were long unimaginable. In 1822, a hunter near the German town of Klütz shot down a stork; when he collected the bird, he saw that it had a wooden spear through its neck, later determined to be of African origin. Hunters eventually found more such Pfeilstorchs (arrow storks), giving credence to the hypothesis that the white stork not only migrated but did so between Europe and Africa. In some ways, this was a downgrade: the seventeenth-century minister Charles Morton, who wrote a popular physics textbook, claimed that birds migrated to the moon. He supposed that they fuelled a sixty-day flight there with body fat (reasonable) and that the journey was made easier by the minimal atmospheric resistance in space (also reasonable).
Migratory birds in captivity develop Zugunruhe, an agitated fitfulness, at certain times of year. Scientists don’t know precisely what provoked A34 to set off northward one spring afternoon, with a flock of her fellows, though, if they did, they might better know how her species will be affected by the shifting seasons of our changing climate. Godwits cannot soar like hawks or glide like albatrosses. They migrate by continuously flapping their wings. They must navigate crosswinds and headwinds, storms and maybe an occasional hurricane, continuing on day after day, night after night. As best as we can tell, they do not, while flying, eat or drink or sleep (at least not with more than one hemisphere of their brain at a time). After a journey of hundreds of hours and thousands of miles, they descend on a snow-covered shore at the Cook Inlet of southern Alaska or another favored breeding ground. They land considerably lighter than when they took off. “Many arriving shorebirds seem to be tired,” the ornithologist and conservationist Joseph Archibald Hagar wrote, in his foundational monograph, “Nesting of the Hudsonian Godwit at Churchill, Manitoba,” from 1966. In a field-diary entry, Hagar describes a group of birds that “within a minute or two dropped into some sunny spot out of the wind, tucked heads into scapulars, and went to sleep, not to move again for as long as we watched.”
In 1976, the young ornithologist Robert Gill took a job with the U.S. Fish and Wildlife Service in Anchorage. He was dispatched to the Alaska Peninsula to do biological inventories on public land that was up for lease to private companies. During those long-lit Alaskan summer days, walking across salt marshes and through the foothills of the mountains, Gill encountered thousands upon thousands of migratory shorebirds. He told me, “In Alaska, where the seasons are so prominent, it’s very dramatic. It feels like all the birds turn up over the course of one weekend in May.” Along with godwits, the peninsula was a summer home to yellowlegs, dowitchers, sandpipers, Arctic terns, and other species. But almost no one was aware that so many birds relied on this land. How the birds managed their journeys, where they might stop along the way, even how many of them there were—no one knew for sure. “In the vast expanses of wetlands and coastal tundra, you could see why,” Gill said.
The extinction of the once common passenger pigeon, famously described by the naturalist John Muir in his memoir (“I have seen flocks streaming south in the fall so large that they were flowing over from horizon to horizon in an almost continuous stream all day long, at the rate of forty or fifty miles an hour, like a mighty river in the sky”), was part of the impetus behind the Migratory Bird Treaty Act of 1918. Godwits are protected under the act, so killing them or holding them captive, even for scientific purposes, is highly regulated. Also, they’re difficult to capture. Gill’s means of learning more about them was limited, he said, to “the kind of observational work done by old-school naturalists.”
In October of 1987, Gill received a call about nine bar-tailed godwits that had crashed into a radar dome near Cold Bay, Alaska, and died. “They were greaseballs,” he recalled. “They made any Christmas goose look lean.” The carcasses were sent to a lab to be analyzed. Fifty-five per cent of their body mass turned out to be fat. Gill suspected that these chubby godwits were preparing to fly non-stop from Alaska to New Zealand, where this species wintered. However, at that time, the longest known non-stop migration flight was barely half that long. “But, if they were going to stop in French Polynesia, why carry all that baggage?” Gill reasoned.
The lab also measured the birds’ internal organs. Gill’s collaborator, Theunis Piersma, noticed something peculiar: the guts, gizzard, liver, and kidneys of these birds were very small—it was like cutting open a lion and encountering digestive organs the size of a house cat’s. Then, in March of 1992, some forty godwit carcasses were seized from a poacher in New Zealand. These were birds in a very different part of their migratory cycle, and their digestive organs, when analyzed, were of more normal proportions. In 1998, Piersma and Gill published their findings in a paper titled “Guts Don’t Fly: Small Digestive Organs in Obese Bar-Tailed Godwits,” concluding that the birds shrank their digestive organs to reduce their weight and their metabolic demands during a non-stop migration. And then, somehow, regrew them.
This conclusion remained debatable. For one thing, Gill and Piersma had no direct evidence that the birds flew without stopping. At the time, there were no tags sufficiently lightweight for tracking birds as small as godwits. But transmitters kept shrinking, and, in 2007, Gill flew to New Zealand, where, after a lot of patient, muddy field work, he succeeded in putting tags on sixteen bar-tailed godwits. The trackers could send signals to satellites to pinpoint the birds’ location. By today’s norms, the trackers were pretty heavy. Many of them failed within months, but one lasted much longer than expected.
A female godwit, E7, took off on March 17, 2007, from near the Piako River, on New Zealand’s North Island. She flew more than six thousand miles non-stop to a nature preserve on the Yalu River, near the China-North Korea border; she stayed there for a little more than a month; she arrived at her nesting area in Alaska on May 15th and spent the summer there. The tracker was still working on August 29th, when E7 started flying southeast, over the Pacific. Gill’s team was doing field work in western Alaska and had only spotty internet service; the team would gather around a laptop, waiting for the updates on E7’s location to come through. North of Kauai, she took a slight right turn and continued flying. On September 7th, after more than two hundred hours aloft, she landed at the mouth of the Piako River, back on the North Island of New Zealand, where Gill had first met her.
Before E7, the longest documented non-stop migratory-bird flight was that of a Far Eastern curlew who had flown about four thousand miles. E7 flew some seven thousand without a break. The flight defied reason. “I had an engineering professor at M.I.T. call me up and say he gave his students an assignment to compare the size and flight range of E7 to a 747 jet,” Gill said.
How these birds could put on so much fat and still be healthy remains somewhat mysterious. “The dogma for mammals is that fat is good fuel for low-intensity exercise—but the flapping flight required for migration is thought to be pretty high intensity,” Maria Stager, an evolutionary biologist at UMass, Amherst, who studies the physiology of songbirds, told me. Marathoners consume sugary carbohydrate-rich gels, not bacon bits. Stager is Nathan Senner’s wife; she assists him in his field work, and he assists her in hers. A couple of years ago, to better understand godwit migration, they began a collaboration with Chris Guglielmo, a professor of biology at Ontario’s Western University and the director of its Centre for Animals on the Move, where he often uses wind tunnels to measure birds’ flight dynamics and metabolism. A wind tunnel works much like those “endless” swimming pools, in which you stay in place while swimming against a current. But the wind tunnel wouldn’t work for godwits. “If I tried to get a bird to fly non-stop for eleven days in my wind tunnel—well, first of all, I don’t think my animal-care committee would approve of it, because the bird would probably die of dehydration,” he said.
Guglielmo had done the math. “We knew how fat the birds got,” he said. “We knew the energy content of fat and nonfat tissue.” According to these measurements, even the fattest of the birds would run out of fuel—body fat and a bit of muscle—after about twenty-five hundred miles. “So not even halfway,” he said.
Guglielmo played around a bit with such variables as drag coefficient and presumed altitude. He eventually came up with parameters in which birds might survive flying six thousand miles non-stop—but only if they could complete the journey in four or five days. Tracking data showed that the migrations were never that brief. “They shouldn’t be able to go seven, nine, eleven days,” Guglielmo said. And yet they did. “They look diminutive, fragile, and delicate. But they’re these high-performance Ferrari machines.”
He had a hypothesis about what was going on. Hummingbirds can save energy by going into torpor at night, lowering their body temperature and their heart rate. Little brown bats can similarly reduce their metabolic demands by going Dracula for months at a time, decreasing their body temperatures by more than fifty degrees Fahrenheit and slowing their respiration to a handful of breaths an hour. Guglielmo wondered whether godwits did something similar, even though hanging motionless in a torpor seems pretty different from flying.
But there were no data on the heart rate and body temperature of migrating godwits. So, in the summer of 2024, Guglielmo joined Stager and Senner during their field work in Beluga. With him were the veterinarian Beverly Chua, a postdoctoral student named Catherine Ivy, and a graduate student, Kevin Young. When Senner and Stager caught a godwit, they would pass it along to Guglielmo and Young, who would drive the bird to a makeshift operating room they had set up at their lodge. Chua would put it to sleep with isoflurane, intubate it, cover its eyes to keep them from drying out, make a small incision in its abdomen to insert a device that would log heart rate and body temperature, and then sew the bird up. The surgery took about twenty minutes. From the birds’ perspective, Guglielmo said, “it must feel like an alien abduction.”
“In total, we placed the trackers in ten birds, five males and five females,” Guglielmo told me. Whether they would see those individuals again was uncertain; the birds would have to survive the summer, fly down to Chiloé Island, survive there, fly back to Beluga, and be recaptured. “When I look at them, I have this little moment and think, They’re going to go off and do these amazing things,” Guglielmo said. The following summer, the team returned, as did at least nine of the ten godwits. The data extracted from the trackers are being analyzed, a slow process.
When I flew into Beluga, on a four-seat Cessna, my bird’s-eye view was of blue-and-green water that softly transitioned into brown-and-green land. The pilot pointed out gray harbor seals and some of the village’s namesake pink-white whales. The two other passengers were working on a project to keep the local Chinook and coho salmon, which are essential to the area’s commercial-fishing industry, from being decimated by the northern pike, an invasive species that preys on the salmon. Beluga, with a permanent human population of thirty-four, is visited by duck hunters, fishermen, oil workers, solar contractors, U.S. Geological Survey scientists, and Senner’s team of ornithological researchers, who come each year to monitor the nesting grounds.
“As extraordinary as their migration is, maybe it has led us to overlook other aspects of their life cycle,” Senner told me one evening. “We have this idea that migration is dangerous and that a lot of birds are likely dying in migration,” he went on. “That’s born in part from the fact that we do occasionally see these mass-mortality events.” A powerful tornado off the coast of Louisiana in 1993 killed three humans and tens of thousands of birds, most of them neotropical migrants—orioles, warblers, thrushes, vireos—who were nearing the end of their migration across the Gulf of Mexico. In the fall of 2020, following droughts and a cold snap in the American Southwest, estimates suggest that more than a hundred thousand migrating birds died—many of them falling directly out of the sky.
“But what we’ve been finding with migratory shorebirds suggests the opposite,” Senner went on. “Migration is not necessarily the most dangerous time of the year.” José A. Alves, at the University of East Anglia, led a team that compared two groups of Icelandic black-tailed godwits. The godwits that wintered farther away, in Portugal, actually fared better than those that wintered in England. “When we think about conservation, we need to think about where in their life cycle they are most vulnerable,” Senner said.
About a hundred and fifty Hudsonian godwit pairs breed in the bogs near Beluga. After a post-migratory rest, courting begins with aerobatic displays by the males, which involve butterfly-like flapping followed by free-fall nosedives from which they gracefully pull out at the last second. The females lead “pursuit flights,” in which they fly swiftly, with abrupt tilts and turns; a male partner follows just behind and below. Sometimes females stay with last year’s partner, sometimes they choose a new partner. Unchosen males, known (alas!) as “failed males,” spend the season flying around in a group, seemingly to harass paired males and to impress paired females.
A godwit couple will scrape a few shallow, saucer-shaped indentations (sometimes referred to as “nest cups”) into a grassy spot, select one of them, and proceed to nest as imperceptibly as possible. Parents sit atop their clutch of eggs (almost always four) on a predictable schedule: the females from about 6 A.M. to 6 P.M. and the males for the remaining twelve hours, with each bird of the couple feeding at the shore in their off-nest time. These four eggs are usually the birds’ one hope during the whole year of producing offspring; the festive godwits of Chiloé become, in the breeding grounds, measured, quiet, and focussed. Nesting is always perilous, but the moment when the male and female trade places is especially so, as the incubating bird’s movement may catch the attention of a predator.
The bogs in late May are a vast expanse of hummocks of yellowed sedge interspersed with small ponds and copses of black spruce where moose like to hang out. Underfoot, the bog is squishy and resilient, with unseen holes here and there. It gets softer and sinkier as spring advances. Wearing thigh-high rubber boots, I spent three days in this landscape, tramping behind Stager and Senner as they sought out nest sites, tracked the progress of eggs, and weighed, measured, and tagged expecting parents.
It was here that Senner handed A34 to me for a moment. She was warmer than I expected a bird to be. I could feel her heartbeat. When I was in elementary school, I briefly shared an elevator with the actor Robert Wagner, whom I recognized from the TV show “Hart to Hart.” He caught my eye and said hello. The encounter was otherworldly and wondrous. Holding A34 felt something like that. Then I opened my hands and she took off, back to her clutch of eggs, which, if not eaten by a coyote or a sandhill crane or another hungry creature, would soon hatch. Life is stressful for Hudsonian godwits: Senner told me that, across godwit studies, he has never seen a rate of chicks surviving to fledging higher than about twenty-five per cent.
Senner began collecting data from godwit nesting sites in Beluga in 2009, when Robert Gill helped him to scout out the terrain. Godwit couples maintain large territories, establishing nests far from other godwits. They prefer dense boggy areas that tend to keep humans away. Their nests are built in existing sedge clumps, with minimal modifications, and are therefore ridiculously hard to find—as Gill put it, they’re “very cryptic,” even for expert eyes. Senner is known for having a “nest sense,” but, as he said, “all that ends up meaning is that rather than spending twenty-four walking hours per nest find, I spend maybe twelve.”
One of the more reliable approaches to nest-finding is to follow a male godwit returning to take over nighttime duties. Late one afternoon, Senner and Stager separately staked out two males. They each waited for about three hours. The godwit males remained in spruce treetops, give or take an occasional short flight. Either the birds were on to them, or they were failed males with no nests to fly back to.
That godwits reproduce at all is astounding. They must shuttle great distances between southern and northern latitudes of the globe, figuring out not only the location of their breeding grounds but the optimal moment to arrive so that their eggs can hatch when insects are at their most abundant. Between 1974 and 2010, godwits were arriving earlier than usual, by as much as nine days. Was this an adaptation to a changing climate? Maybe, but, between 2011 and 2023, the godwits’ arrival date shifted again, to as many as six days later. “I used to be able to say, ‘Come up here on June 1st and you will definitely see chicks hatch,’ ” Senner told me. “But I can’t really say that anymore.” This second shift seemed counterintuitive and maladaptive, since peak insect abundance is directly related to snowmelt. “One of the closest correlations to arrival date is when spring came the previous year, which makes it seem like the birds remember that,” Senner said. With climate change, the bogs are drying out, so there are fewer insects for young chicks to eat. Yet more nests are hatching, even as a smaller percentage of those chicks are surviving.
Stager recalled a long evening she and Senner once spent looking for nests: “This beautiful thunderstorm was approaching, and we were, like, ‘We should not be in this open bog right now, but also we need to be banding these chicks.’ ” They were searching near where a male godwit was resting in a treetop, indicating a nest nearby, but they were having no luck finding it. Then the male began “making these horrible distressed calls that I’ve never heard another bird make,” Stager said. She and Senner spotted a northern harrier. Their approach startled the predator, who took off with the mother godwit in its claws. When the father flew down to his chicks, Stager and Senner managed to catch and tag all the birds—“He was pretty angry with us,” Stager said—then retreated from the stormy bog. The father was left to tend to the chicks himself until they were old enough to survive on their own. At least two of those four chicks survived, Senner told me. He knew because those birds returned to Beluga a couple of years later. “Usually, even with two parents, very few chicks make it,” he said. “I thought, Wow, he is a really great dad.”
Chicks can walk within a few hours of hatching, but it’s several more weeks before they can fly. By the end of this year’s breeding season, about twenty per cent of the hatched chicks had fledged. It was a good year. In one nest, three of four chicks survived. In some other nests, no chick lived beyond a week. One of A34’s chicks survived. On my last afternoon in Beluga, Stager told me, “I don’t consider myself a conservation biologist like Nate—it would make me too sad.”
Godwit parents brood their chicks, alert them to danger, lead them to hiding places, and (in a dramatic and short-lived personality shift) aggressively squawk at and harry their potential predators. Then, in July, the adults begin their southward migration, leaving their young behind. Although much remains unknown about godwits in general, even more remains unknown about the juveniles. They have been observed leaving Alaska in August and September, though it’s unclear how they find their way. Hudsonian juveniles have now and again been spotted in New Zealand and Australia, rather than in South America, among flocks of bar-tailed godwits. More recently, the scientists Juan G. Navedo and Jorge Ruiz, from the Universidad Austral de Chile, tagged some birds in Chiloé and discovered that, instead of travelling to Alaska in the spring to breed, they spent the boreal summer in the pampas of Argentina.
Sixty years ago, the naturalist and writer Peter Matthiessen observed in this magazine that the Hudsonian godwit was among the most precarious of the North American shorebirds: “It is an exceptionally unassertive bird, readily chivied by marbled godwits, and even sanderlings. Was it always so timid, or is the degeneration brought about by mutation? Has it become specialized in some way not yet understood? . . . The naturalist who could find answers to such questions would explain a good deal that we do not know about ecology and ethology and genetics.”
Money and political will being scarce resources, questions of where and when to apply them are the constant companions of conservation science. The long-term survival of Hudsonian godwits—and migratory shorebirds more broadly—depends to a significant degree on scientists figuring out what efforts will be most effective. “I hate to say it, but you might call it an optimization problem,” Nathan Senner told me.
“Tidal mudflats have suffered from not being perceived as beautiful sights,” Wilcove, of Princeton, said. The dun-colored flats often stretch for miles. “The degradation of a tidal flat is not as apparent as the clear-cutting of a forest or the damming of a river,” he went on. “It just looks like a place you don’t want to walk, because it’s really hot and you could sink down to your waist. It’s hard for people to imagine that it’s an incredibly vibrant and important habitat for so much wildlife.”
The Western Hemisphere Shorebird Reserve Network, founded in 1985, initially focussed on setting up what Stanley Senner described as “a string of pearls” consisting of wetlands along migratory routes, with Alaska’s Copper River Delta becoming one of the first of more than a hundred designated sites. “But now we’re coming to understand that it’s not enough,” Senner said. Smaller-scale interventions also do essential work. In California, for example, rice farmers are paid to flood their fields during key weeks of the year, for the use of migrating birds. W.H.S.R.N. has collaborative conservation projects at sites up and down the Americas, including at ranches in Uruguay, salt ponds in Ecuador, and shrimp farms in Honduras. In Chiloé, Senner’s colleague Natalia Martínez-Curci, of Argentina’s National Scientific and Technical Research Council, has spent years working with the local aquaculture industry, along with members of the Indigenous community, who recently built a bird observatory.
But, of course, migratory shorebirds aren’t limited to the Western Hemisphere. Scientists studying the East Asian-Australasian Flyway (which runs roughly from Alaska and Siberia down to New Zealand and Australia) spent time trying to identify what the various migratory bird species in steepest decline had in common. Was it body size? Breeding range? Migratory distance? The shared variable turned out to be reliance on the coastal wetlands of China’s Yellow Sea. Between 1980 and 2014, about a third of that coastline was lost to land reclamation. Tong Mu, a thirty-five-year-old researcher at Princeton, said that when he began his graduate work on migratory shorebirds of the flyway, in 2014, “everything seemed very gloomy to me, and to many people.” Mu did his Ph.D. under Wilcove, working to identify which parts of the Yellow Sea flats were most used by birds.
In 2018, following much clamoring by scientists, the Chinese government enacted strict restrictions on commercial land reclamation along its coast. In 2019, parts of the Yellow Sea mudflats were named a UNESCO World Heritage site. “I would say that the government realized that sustainable development and ecological conservation are a very important part of the story that they want to tell,” Mu said. He recalled doing field work with a much older researcher who said, half joking, half complaining, that science and conservation have nothing to do with each other—that, regardless of how excellent the science is, policymakers will only hear what they want to hear. “But I think science is still very important,” Mu said.
I asked him for his impression of what migratory shorebirds are like—what his sense was of their personalities, if it was even O.K. to use the word “personality” in relation to birds. He was quiet for a moment. “Sorry, it makes me a little emotional to talk about it,” he said, smiling. Mu spent five Arctic summers in far-eastern Russia, where mating pairs each have their own territory. He grew more attached to them in that setting, witnessing their individual dramas. “There are some success stories,” he said. “But also many failures. The birds’ nests may be depredated. Or they may have terrible weather, and the chicks can’t survive it. And, you know, they have travelled thousands of kilometres, just for that.”
Mu recalled placing a young chick under his hat, to keep the bird warm while he prepared to tag it. “When they are very young, they cannot maintain their body temperature, and have to be covered by the adults every now and then,” he said. The chick called out in distress. An adult bird flew over, landing on Mu’s head. He took off the hat, and the adult dove in after the chick. ♦