At barely 5:30 in the morning Tiedun Island is already buzzing with action. The rocky islet off the coast of Zhejiang Province is steeped in mist, but the rain that has smothered eastern China for days has finally stopped. More downpour is imminent, providing only a brief window for a covert operation that’s been stalled for days. “We should do it now,” says Don Lyons. “There’s no time to lose.”
Crowding around a computer screen in a cramped hut, Lyons, director of conservation science for Audubon’s Seabird Restoration Program, and his Chinese colleagues are trying to pick out their target via a live stream. They swivel the mouse to scan the nearby bustling seabird colony and then zoom in on a single bird incubating an egg. The black-and-white speckled oval it’s sitting on looks like any of the thousands of tern eggs laid on Tiedun this spring, but it’s a singular life hiding in plain sight. It belongs to one of the 69 critically endangered Chinese Crested Terns among the island’s more than 4,600 Greater Crested Terns.
With only 100 or so individuals globally, the Chinese Crested Tern is one of the rarest avian species on Earth. Asian birdwatchers call it the “bird of legend,” a moniker inspired by the tern’s return from oblivion. The sleek seabirds were thought to have gone extinct nearly a century ago, only to be rediscovered serendipitously in 2000. Despite renewed interest since then, little is known about the life cycle of these feathered seafarers, especially where they go outside of breeding season, where they overwinter, and their migratory routes between those places.
The team staking out the egg is hoping to fill in some of those gaps by attaching, for the first time ever, a satellite tag to an adult Chinese Crested Tern. “Satellite tracking could provide the urgently needed, vital information to help save the species,” says Fan Zhongyong, an ecologist at the Zhejiang Museum of Natural History in Hangzhou, who has been trying to conserve their breeding colonies in eastern China for 16 years.
Concealed in a hut abutting the nesting grounds, Fan, Lyons, and Lu Yiwei, another Zhejiang museum ecologist, survey the colony with binoculars. The relatively few Chinese Crested Terns here depend on their close relatives—greater in both size and abundance—for protection from predators. As a human visitor quickly observes, safety in numbers makes for a deafening, squabble-filled existence. Terns guard their territories fiercely, stretching their necks to peck at neighbors that wander too close. Hundreds more circle overhead, their long, pointed wings slicing rhythmically through the misty summer sky.
The trio gets eyes on the target nest. “Let’s go,” Fan says briskly. The terns take flight as the scientists approach, hovering in midair like miniature helicopters, flapping their wings and emitting hard wep wep calls. White liquid splats Lu’s forehead and drips down it. “They love pooping at intruders,” he says, wiping his face. Undeterred, the researchers run straight for a lone egg sitting in a shallow pit. They look around for the markers—a boulder, solar panels, other nests—that they had noted on the computer monitor. Confident they have the right egg, Lu places a wire trap over it. He opens the cage door and double-checks the trigger. The researchers race out of the colony.
Back in the blind, they wait for an adult to return to the egg; tern parents share nest duties, and it’s impossible to determine the sex without a DNA test. Fan spots one of the parents overhead, and everyone watches it circle a few times before landing. It walks around the trap in seeming confusion, its eyes fixated on its egg. It pauses at the open door, then walks around the cage again. Its neighbors squawk in protest when it crosses invisible territorial lines. The Chinese Crested Tern is too focused on the egg to notice.
The researchers watch with nervous tension. There’s a lot at stake. And to tag the bird, they need to get it safely in hand. The primal drive to attend to its egg is so strong that the tern would risk almost anything. But will it?
erman naturalist Heinrich Bernstein discovered the species now known as the Chinese Crested Tern in 1861 on Indonesia’s Halmahera Island. At the turn of the century birders reported breeding colonies on islands off eastern China, thus endowing the bird its name, and wintering populations in Southeast Asia, including Indonesia, Malaysia, the Philippines, and Thailand. A Chinese zoologist collected 21 specimens along his country’s northern coast in 1937, and that was the last anyone saw of the species for decades. Chinese Crested Terns, scientists surmised, had blinked out.
Then, in 2000, Taiwanese wildlife photographer Chieh-Te Liang stunned the bird world when he photographed four Chinese Crested Tern pairs nesting amid Greater Crested Terns on China’s Matsu Archipelago.
Two years later, Chung-Wei Yen, an ornithologist at Taiwan’s National Museum of Natural Science, visited the Zhejiang museum and mentioned the discovery to its deputy director Chen Shuihua. Though the news had made international headlines, Chen—an urban bird expert—had missed it. He became intrigued as he listened to Yen muse about whether the terns might breed on any of the thousands of islands off the coast of Zhejiang, in the species’ historic range. So much so that in 2003 Chen embarked on a four-year expedition to find the elusive tern.
Chen and colleagues scoured 1,301 islets in the Zhoushan Archipelago. They found Bridled Terns. Roseate Terns. Black-naped Terns. But islet after islet turned up not a single Chinese Crested Tern.
In the summer of 2004 they moved 60 miles south to the Jiushan Archipelago. The 70-plus islets had been designated a provincial nature reserve for protecting the common Chinese cuttlefish, large yellow croaker, finless porpoise, and Black-tailed Gull. Chen’s team was tasked with conducting a survey of flora and fauna, and all the while they kept an eye out for the bird of legend.
On August 1 the team was supposed to visit the last islands. “It was extremely foggy. We couldn’t see anything tens of meters away,” says Chen, who convinced the reluctant boat captain to go out. “It’d be a shame if we didn’t get to complete the survey,” Chen recalls thinking. “What if something unusual were there?”
Nothing unusual transpired until the boat approached Jiangjunmao, or “General’s Hat,” so called because its steep sides and vegetation-covered flat top resemble a military cap. Loud cries reverberated in the air. Little black dots sliced through the thick fog. “We couldn’t believe our eyes! There were thousands of Greater Crested Terns,” says Chen. It was the largest seabird flock they’d encountered. What’s more, they knew that Chinese Crested Terns tend to breed among their close kin. Searching with binoculars, they spotted around two dozen of the rare birds amid 4,000 Greater Crested Terns.
A visual ID, however, isn’t solid evidence. Chen was itching to go back to Jiangjunmao with a long camera lens to get proof. But two weeks later Typhoon Rananim struck, and as soon as it dissipated Typhoon Megi began to form. “I knew even if the colony could survive Rananim, Megi would deliver the fatal blow,” says Chen. “I wanted to get there before Megi did.”
Boat captains laughed at Chen. Nobody wanted to sail into an impending typhoon. A villager called the plan “suicidal.” Chen didn’t waiver. “I was determined to get there,” he says. “Nothing else seemed to matter.” A fisherman finally agreed. The little wooden boat was pushed around by waves several meters high, and the crew scooped out endless buckets of water to stay afloat. “It seemed we would never make it,” says Chen.
Eventually they did. As Chen climbed the General’s Hat, he saw the havoc wreaked by Rananim. Broken egg shells littered the colony. A few chicks wandered around in a state of confusion, apparently abandoned. Some adults, including a few Chinese Crested Terns, had stayed to incubate eggs, and Chen managed to snap a few close-ups of the legendary birds. He returned a few days later, after Megi subsided. The colony was totally deserted.
Chinese Crested Terns didn’t return until three years later, in 2007, when eight individuals bred among 2,000 or so Greater Crested Terns. The nature reserve sent staff members to guard the colony around the clock. When food and water stores ran out, they left for one night to restock. In their absence, fishermen landed and poached all of the eggs. They had decimated one of the two known breeding sites of a species struggling on the brink of extinction.
“It was utterly devastating. The sense of doom and gloom was indescribable,” says Chen, his voice shaky, tears filling his eyes. The birds left. They never returned. It was the lowest point of the Chinese Crested Tern story. “I remember asking myself: What was wrong with China?” he says. “What was wrong with the Chinese?”
he Chinese are hardly alone in hunting birds for their eggs, meat, and feathers. People have been doing so across the globe for eons. Feather hats, for instance, propelled the precipitous decline of Snowy Egrets and other North American wading birds in the late 19th century. Public outcry led to the formation of Audubon Societies that contributed to the passage of protective laws like the Migratory Bird Treaty Act.
In China, avian conservation is still in its infancy, especially for seabirds. The forestry bureau oversees birds but has no experience in extending their duties to the sea, whereas the oceanography bureau is responsible for only marine life. Terns, then, fall in a regulatory loophole. Consequently, a 1989 law banning bird hunting and egg poaching was poorly enforced.
“Lack of awareness was much to blame,” says Zhang Ankang, a Xiangshan oceanography bureau official. Bird eggs were popular in local restaurants, and fishermen collected them to eat or sell. Overfishing has caused catches to plummet in recent decades, and eggs provided supplemental income. Villagers harvested eggs right in front of Chen on the Zhoushan Archipelago and other areas of the Zhejiang coast. “To them, it’s as natural as accepting a present from heaven,” he says.
For terns, the loss of eggs upsets their natural cycle. Instead of heading south in late summer before peak typhoon season begins, they’ll stay and lay a second clutch. In 2004, when Chen discovered the terns on Jiangjunmao, a reported egg-harvesting incident in the region may have prompted the birds to breed anew on the islet in July, only to be pummeled by typhoons Rananim and Megi. “It’s a double whammy,” says Chen.
A turning point came in 2010. In response to the 2007 incident, the Xiangshan government and Zhejiang Museum of Natural History organized an international seabird-conservation conference. For the first time, representatives from the two regulatory bureaus met and agreed to work together to create policies to protect seabirds and dedicate resources for better monitoring and management. Local authorities publicized the existing law on billboards at major traffic junctions, drawing attention to the fact that bird hunting and egg poaching were criminal offenses. They distributed leaflets to restaurants and fishing villages. They mobilized police spot checks at local markets and restaurants. “After a few fishermen were arrested for violating the law, villagers realized that the governments took it seriously,” says Zhang, then the Jiushan reserve’s manager. “The situation gradually improved.”
Zhang and others, meanwhile, wondered if they could lure terns back to Jiangjunmao. The desire was driven by concern for the species, but it was also a matter of pride. The Chinese Crested Terns’ presence there had helped elevate the Jiushan reserve to national prominence. “But the birds never returned to Jiushan after the 2007 incident,” says Chen. “It was sort of embarrassing.”
The Japanese and American ornithologists they turned to for advice suggested they try social attraction—using decoys and audio playbacks of calls to entice birds to nest. These techniques, pioneered by Steve Kress, the founding director of Audubon’s Seabird Restoration Program, have convinced dozens of seabird species to colonize nearly 100 locations worldwide. “Terns are particularly responsive,” says Kress.
By that time, Chen and his colleagues had learned more about the bird’s behavior by studying a small colony discovered in 2008 on Wuzhishan Archipelago—an area Chen explored in 2003—60 miles north of Jiangjunmao. The researchers knew the terns’ arrival and departure windows, incubation and fledging periods, and the characteristics of successful nesting grounds.
Armed with that insight, Chen convinced the Xiangshan government to try social attraction. It chose Tiedun, an islet in the Jiushan reserve that is much less steep than Jiangjunmao and thus more accessible for researchers. Still, Tiedun needed work. “A bit of ecological engineering was necessary to make Tiedun suitable,” says Fan.
In April 2013, aided by seabird experts, including Lyons, Kress, and Daniel Roby, a tern expert at Oregon State University, Chen and colleagues sprinkled gravel to imitate natural nesting sites, pruned shrubs so terns could spot predators, and deployed rat and snake traps. Then they placed 300 tern decoys and installed a solar-powered system to broadcast tern calls recorded on Wuzhishan.
To minimize disturbance, Ding Peng of the Jiushan nature reserve and Stefanie Collar, an Oregon State University graduate student, monitored the would-be colony from a neighboring islet with binoculars. In early May, when terns normally arrive, a few passed through. “They were rather curious about the decoys. Some offered them fish, others even tried to mate with them,” says Ding, laughing. “But none stayed.”
It was a long wait, exacerbated by language barriers. Collar didn’t speak Chinese. Ding’s English was limited, and he couldn’t understand the Xiangshan dialect of the local cook who helped them make camp. “We mostly used body language to communicate,” says Ding. “It can go a surprisingly long way.”
By late July the team was ready to give up. “We thought we didn’t get the breeding site right. We thought they didn’t like it,” says Ding. When they reached Tiedun to collect the gear, they realized the audio playback system was broken. They fixed it and decided to leave it on for a few more days.
The following morning—a glorious day, Ding recalls, the sky a cloudless, crystal blue—hundreds of Greater Crested Terns and a few Chinese Crested Terns gathered on Tiedun. “I had never seen so many seabirds before,” Ding says. In the next few days, 3,300 or so Greater Crested Terns and 19 Chinese Crested Terns amassed and began to breed. (Researchers suspect they abandoned their first colony, possibly due to a mid-July typhoon.) The team kept close watch on Tiedun until October, when the adults and more than 600 Greater Crested Tern fledglings and at least one Chinese Crested fledgling left for their winter grounds.
The team built a hut on Tiedun to more closely monitor the colony (and the audio system). One room houses a computer monitor linked to the surveillance camera, along with two beds for volunteers; the other doubles as a kitchen and overflow bedroom. In 2015, researchers began employing social attraction on Wuzhishan to increase the population there. In 2018, the two sites tallied 77 adult Chinese Crested Terns and 25 chicks.
In addition to three known breeding colonies—Tiedun, Wuzhishan, and Matsu, in the Taiwan Strait—two more have popped up. A second in the Taiwan Strait, and another on a South Korean island where researchers were surprised to find the terns breeding amid Black-tailed Gulls.
Still, Chinese Crested Terns are most frequently spotted along China’s eastern coast. And these days, more and more people are looking for them. After the conference in 2010, the government rolled out education and outreach campaigns. Chen and colleagues began sharing the legendary birds’ tale and their plight in schools and fishing villages. Local and national media frequently feature conservation initiatives to safeguard the tern. A 2018 exhibition on the species at the Zhejiang Museum of Natural History attracted hundreds of thousands of visitors. Today hundreds of people apply to be volunteer tern monitors on Tiedun, branded (with no mention of guano splats) as “the most poetic job” in the province.
ack at Tiedun, the researchers are transfixed by the Chinese Crested Tern’s frustrating reluctance to enter the trap. As they wait, another of its kin returns with a wriggling fish in its bill. Its partner and offspring shriek out to it as the bird lands and feeds the hungry chick.
Today Tiedun and Wuzhishan host about 80 percent of breeding Chinese Crested Terns, and the two sites produce dozens of chicks a year. Yet having so many birds concentrated in two places is a precarious situation for a critically endangered species.
“They can be easily wiped out by typhoons” or major pollution incidents, says Fan. “It would be devastating.” The researchers are planning to employ social attraction on other islands, including those farther north, which are less susceptible to typhoons that are likely to become more frequent and more intense due to climate change.
Other threats abound, such as overfishing. While a strict ban exists June through September, there’s no catch limit outside that period—a situation that depletes fish that sustain terns. And while poaching has dropped off, fishers still harvest seaweed and shellfish from islets, disturbing the birds. Burgeoning tourism in coastal islands could affect seabird colonies outside protected areas, too. The birds may also be putting themselves at risk. Genetic analyses show that some Wuzhishan terns are fertile hybrids of Chinese and Greater Crested Terns. That means pure Chinese Crested Terns could eventually breed themselves out of existence, says Chen, though the hybridization rate is less than 5 percent now.
While researchers have a clear picture of the birds at known breeding colonies, they’re trying to learn where the terns spend the rest of their time and what threats they might encounter elsewhere. Since 2015, they have banded nearly 900 Greater Crested Terns and 5 Chinese Crested Terns. Re-sightings can help trace their movements and identify important habitats, but the approach is inefficient and at best offers only a snapshot of what’s going on. Satellite tags, by contrast, offer a more granular picture of their life cycle. “Whether we can lend a helping hand to the ‘bird of legend’ will depend on whether we can lift the shroud of their mystery,” says Chen. “Satellite tagging is an important way to go about it.”
Hence the tension over the would-be captive on Tiedun. After walking around the cage a few more times, at last it cautiously steps in. It sits on the egg and wiggles back and forth to get into a comfortable position. The researchers don’t let it rest long.
Fan, Lu, and Lyons rush into the colony, sidestepping nests. Once again thousands of terns take flight. When the bird in the cage flaps its wings to join them it triggers a suspended wire that shuts the door. Lyons reaches the trap moments later. He gently removes the nervous creature, puts it into a linen bag, and returns to the hut.
When Lu removes the tern from the bag, it calmly turns its head and takes in its surroundings. “Look at its glossy black crest,” says Lu. “It’s still in the breeding plumage. How beautiful!” It looks relaxed as Lu holds it with both hands, his thumbs gently stroking its feathers. After banding the bird, everyone gathers to take photos of ZE5, soon to be a legend among legends.
To attach the satellite tag, Lyons puts a tiny harness on the bird, looping the straps around its legs.
“The trick is to make it tight enough so it doesn’t fall off but not too tight to affect the bird in any way,” says Lyons, who speaks from experience, having tagged 20 species of birds. He adjusts the straps until they’re just right, then ties a knot at the end and fixes it with super glue. Fan and another member of the Zhejiang team measure the bird’s body weight and the length of its beak, torso, and wings. They pluck a couple of feathers for genetic analysis. Then they release ZE5.
The following morning, Lyons wakes up at 5 a.m. The tangy scent of the ocean permeates the island. The first thing that comes to his mind is ZE5. “Where is it now?” he wonders. “How is it doing with the tag?” He grabs his binoculars and rushes to the colony edge.
Under the soft glow of the breaking dawn, Lyons sees ZE5 sitting on its nest. Its shaggy crest spikes up in the wind, like a punk mohawk. As the bird shifts on its egg, Lyons can just make out a thin wire antenna sticking up. He is ecstatic. “It’s a huge relief the bird is doing well, still very motivated and interested in nesting,” he says. “It’s a new dawn on what we are going to know about this species and how we can help it.”
ost of the researchers leave Tiedun a few days later, but ZE5 remains within arm’s length. They obsessively track the bird’s whereabouts, watching in real time on a cell phone mapping app as it forages near the colony. For unknown reasons, the egg doesn’t hatch. The would-be parents eventually abandon the nest in early July, and ZE5 starts to venture into the open ocean. Though its average range is 40 miles, half the time it stays closer to Tiedun, covering a distance of about 7 miles. Its trips almost completely overlap with those of the five Greater Crested Terns also tagged this year, hinting that some birds that breed at the same sites may migrate to the same places.
ZE5 occasionally makes some longer trips. On July 11, for instance, 20 days after it was tagged, it flew 62 miles to the colony on Wuzhishan. The researchers suspect that ZE5 might have bred there before. Perhaps it was scouting potential sites for mating and nesting in the future, as terns commonly do. The highly social, adaptable birds tend to visit a number of sites each year and have extensive knowledge of potential breeding grounds, Lyons says.
Thirty-seven days after being tagged, ZE5 sets out to the ocean yet again. This time, the signal is lost. Maybe the tag stopped working. Maybe the harness broke and the tag fell into the ocean. Maybe the bird slipped out of the harness. Or maybe it died.
The researchers are crestfallen, even though they were aware of this possibility. Chinese Crested Terns are slightly smaller and lighter than Greater Crested Terns, which have been tracked for up to a year. To reduce the impact on the bird, the team opted for a two-gram tag. The five Greater Crested Terns sported five-gram tags; three were still functioning as Audubon went to press. The lighter tag uses a more delicate battery and smaller solar panels. The material in the harness is also thinner and likely less durable.
“Our top priority is to make the tagging as safe for the bird as possible,” says Lyons. “It’s always a trade-off. We may have risked the bird shedding the tag earlier than desired, but have, hopefully, minimized the risk of injury or death.”
Seeing that the tracker didn’t appear to impede ZE5’s movements gave the team confidence that the larger gadgets used to track other tern species may be suitable for Chinese Crested Terns, too. They’ll likely attempt to affix bigger, more durable tags to terns at one of the few known wintering sites in Indonesia in January and on Tiedun next summer.
While their exact movements remain a mystery, fascination with Chinese Crested Terns is spreading beyond China. Birders as far east as South Korea and as far south as Indonesia, some 2,400 miles from Tiedun, are increasingly eager to glimpse the rare species. Across the bird’s historic grounds, amid flocks of Greater Crested Terns and Black-tailed Gulls, they’ll keep their binoculars peeled. Through international birding forums, many have heard about ZE5, and this winter they’re on the lookout for the red-and-white band on its right leg. Meanwhile, ZE5’s fan base in China is already anxious to see if it returns. “Hopefully, we will see it again on Tiedun or Wuzhishan next summer,” says Fan.
This story originally ran in the Winter 2019 issue as “A Legend Among the Masses.” To receive our print magazine, become a member by making a donation today.