[The answer to the mystery — unfolding in passages recorded by satellite for more than five months — has been a humbling revelation even to many experts. The birds’ journeys have so far covered thousands of miles, across a total of a dozen countries and an ocean. The “common cuckoo,” as the species is called, turns out to be capable of exhilarating odysseys.]
By Chris Buckley
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Skybomb Bolt, a common
cuckoo, after he was fitted with a
satellite tag in May at
the Hanshiqiao Wetland in Beijing.
By late October, he had
flown to Africa.
Credit Terry Townshend
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BEIJING
— When Flappy McFlapperson
and Skybomb Bolt sprang into the sky for their annual migration from wetlands
near Beijing, nobody was sure where the two cuckoos were going. They and three
other cuckoos had been tagged with sensors to follow them from northern China.
But to where?
“These birds are not known to be great fliers,”
said Terry Townshend, a British amateur bird watcher living in the Chinese
capital who helped organize the Beijing Cuckoo Project to track the birds.
“Migration is incredibly perilous for birds, and many perish on these
journeys.”
The answer to the mystery — unfolding in
passages recorded by satellite for more than five months — has been a humbling
revelation even to many experts. The birds’ journeys have so far covered
thousands of miles, across a total of a dozen countries and an ocean. The “common
cuckoo,” as the species is called, turns out to be capable of exhilarating
odysseys.
“It’s impossible not to feel an emotional
response,” said Chris Hewson, an ecologist with the British Trust for
Ornithology in Thetford, England, who has helped run the tracking project.
“There’s something special about feeling connected to one small bird flying
across the ocean or desert.”
But to follow a cuckoo, you must first seduce
it.
The common cuckoo is by reputation a cynical
freeloader.
Mothers outsource parenting by laying their
eggs in the nests of smaller birds, and the birds live on grubs, caterpillars
and similar soft morsels. British and Chinese bird groups decided to study two
cuckoo subspecies found near Beijing, because their winter getaways were a
puzzle. In an online poll for the project, nearly half the respondents guessed
they went somewhere in Southeast Asia.
“We really didn’t know for sure,” said Yu
Fang, a coffee importer, a prominent member of the Beijing bird-watching
community and a volunteer on the project.
“We knew that the cuckoos breed around here.
But where do they go over winter? I guessed it was India,” Mr. Yu said. “I’ve
been bird-watching in India, and they are often spotted there. I thought that’s
where they stopped.”
To tag the birds, the team set up soft,
barely visible nets in May to safely catch the birds. A stuffed female cuckoo
was attached to a tree or bush, and a recording of the bird’s come-hither
mating call was played out.
They responded lustily.
“The male cuckoos just can’t resist. They
come in from a long way,” said Mr. Townshend, who works as a consultant on a
variety of environmental projects. Unexpectedly, female cuckoos also came to
the party, seemingly jealous about an apparent rival in their patch, he said.
After excluding birds too light to safely
carry the sensors, the team attached solar-powered tags weighing 0.16 ounces to
the backs of five birds, each weighing around 3.5 ounces, and freed them into
the wild, where satellites followed the signals from their tags. Such
technology has revolutionized the study of migratory birds since the 1990s.
“Tracking technology has ushered in a new age
of exploration,” Mr. Hewson said.
But the project was also intended to raise
awareness of wild birds and their needs, especially in China, where expanding
cities, pollution and commercial capture with huge nets threaten the creatures.
Schools in Beijing for local and foreign children gave the birds their names.
As well as Flappy and Skybomb, there was Hope, Zigui and Meng Zhi Juan, a
poetic Chinese phrase meaning “dream bird.”
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A map showing the
migration routes of several cuckoos heading toward Africa as of Nov. 1.
Credit Google
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The wait began. As blazing summer arrived,
time approached for the birds to begin their migration. But not all could.
Cuckoos often have brief lives. The trackers ran out of contact with Hope after
she flew north to Russia, possibly dying or losing her tag. And Zigui’s signal
stopped near Beijing, where he probably perished.
Then in early August, Flappy struck south,
followed weeks later by Skybomb and then Meng Zhi Juan. Each day, Mr. Townshend
checked the satellite data to see whether any other birds were on the move.
Their journeys, chronicled on Twitter, drew in more and more fans, including
me.
By mid-September, Skybomb and Flappy were in
India. That more or less ruled out the idea that they were headed to Southeast
Asia, and they appeared likely to head west. But by which route?
The first answer came in late October. Skybomb
struck out boldly from central India and, without stopping, headed across the
northern Indian Ocean, apparently aiming to reach Africa in one lunge. It was a
breathtaking gambit for one of these small creatures.
“When Skybomb set out across the ocean, it
was like, Whoa! He’s going for it,” Mr. Townshend said. Skybomb had fattened on
grubs, but Africa was thousands of miles away without the prospect of a stop or
meal in between.
“It was a real celebratory moment,” Mr.
Townshend said. “But fingers were crossed that he was going to make it across
the ocean.”
There was an implacable logic in the cuckoos’
seeming folly, said Mr. Hewson, who had guessed that they would go to Africa.
They stopped over in India when rains had still left plenty of food there and
waited for the monsoon winds to make a drastic turnaround, so the birds could
fly onward with the help of the breeze. Cuckoos that summer in Europe also head
to Africa to avoid the winter.
Skybomb plowed on. Flying at roughly 2,600
feet above the sea, he held to an astonishingly straight path, apparently calibrating
for shifts in the wind and conditions. By the second day, he was halfway
across. After a third day, the east coast of Africa, and food and rest,
beckoned.
For much of the flight, Skybomb was helped by
tailwinds. But as land approached, crosswinds and then a front-on headwind
struck. It was a moderate breeze, but maybe enough to exhaust a cuckoo after
days without stopping.
On Oct. 31, Mr. Townshend announced on
Twitter that Skybomb “is in Africa!”
Sixty-four days after he had begun his
migration, the cuckoo had reached the coast of Somalia about an hour after
dusk. He had flown nonstop for 2,300 miles from central India. “What a bird!”
Mr. Townshend declared.
But even then, Skybomb was not done. Right
way, he flew for another 190 miles until he reached an area where recent rains
would have brought a proliferation of caterpillars and grubs to eat. Somehow,
he knew where to follow the rain.
The other birds began their long flights
later than Skybomb. Flappy took a more cautious path, crossing the Arabian Sea
from India to Oman. That made for a shorter flight over water, but also meant
she hit land in northern Africa, farther from the lusher terrain to the south.
Meng Zhi Juan is still in India this week. He is apparently poised to follow
the same long route as Skybomb.
The birds appear likely to edge south in
Africa, following the rains. If they survive, they are expected to arrive back
in Beijing in May.
Mr. Townshend and his colleagues hope to
follow more cuckoos next year, if they attract enough donations to pay for the
tags and satellite services. More knowledge will help protect the areas they
need to stop in.
“They’re birds that are shared by China,
India, Myanmar, Somalia and wherever else they go,” Mr. Townshend said. “With
that comes a shared responsibility to protect them.”
Follow Chris Buckley on Twitter @ChuBailiang.