A migratory odyssey: tagging Eurasian curlew shorebirds

Whimbrel appears in the late-afternoon sky over Deveaux Bank, a small island – a sandbar, in fact – just off the coast of South Carolina south of Charleston. Crouching in the dunes, correspondent Martha Teichner watches with the scientists studying them.

Maina Handmaker, a graduate student at the University of South Carolina, remembers the first time she saw what we were seeing: “And as we got closer to sunset and the high tide came, it was was the most amazing thing I have ever seen: hundreds of crows curlews. just sinking on the horizon. “

Birds clouds against the sunset. You say to yourself, memorize the sight, then whisper to your soul: I’m happy to be alive so I can witness this amazing thing.

At nightfall, they land and sleep. Who knew? Until Felicia Sanders, a bird biologist with the South Carolina Department of Natural Resources, found herself at Deveaux Bank one spring morning in 2014, anybody knew.

“I was really surprised!” Sanders said. “Only thousands of whimbrel came out of the island just at sunrise. And to have so many in one place in Deveaux Bank, it seemed very unusual, and maybe something no one else had. discovered.”

The world-renowned Cornell Ornithology Laboratory at Cornell University has called it “one of the most breathtaking discoveries in the history of 20th and 21st century ornithology.” Why? Because raven curlews are disappearing quickly.

“These birds have declined steadily over the past decades by 4 to 5% per year,” said Andy Johnson, who produces videos for the Cornell Lab. His academic study was curlew procession.

Teichner asked, “Why are they in decline?

“There is sea level rise and development on the coasts that converge and compress their foraging and roosting habitat,” said Johnston. “And there are aspects of climate change that affect the timing of food availability. It’s complicated! Yes, they have a wide array of things hitting them from all sides.”

What is most remarkable about a Whimbrel is its long upturned bill, perfect for plucking crabs and other crustaceans from wet sand.

Johnson said: “Whimbrel’s are big enough for shorebirds. I mean, they’re probably almost a foot tall, long legs, long necks. But they’re lighter than they are. look like it. You know, they certainly weigh less than a pound. “

Which makes their annual migration of 5,000 to 10,000 miles even more remarkable. They winter along the northern coast of South America. On their way to their summer breeding grounds, they take a break of about a month to rest and fatten up for their non-stop flight to the Arctic. Once their chicks hatch and can fend for themselves, they turn around and head south again.

Sanders said: “The best estimate for this species is 80,000, and that of the eastern population, the one up and down the Atlantic coast, is 40,000.”

A formal count on Deveaux Bank in 2019 amazed bird watchers. “We had almost 20,000 curlews in Deveaux,” Sanders said.

This is half of the entire population of the East, on this fragile and ever-changing high ground.

All kinds of sea birds take shelter on the Deveaux bank. Huge colonies of pelicans, terns and gulls. Its continued existence as a refuge is essential to the survival of the Whimbrel.

The moon would be full on April night “Sunday Morning” was there. The goal was to capture birds, tag them, and attach tiny solar-powered trackers, to know where they are going and how best to help them survive.

Handmaker said: “We still have an hour before high tide, however. We know the high tide is going to be a bit higher than last night. So we were sort of figuring out where the water might come from tonight, and where we think the raven curlew will perch tonight and set the net accordingly. “

Curlew procession suspicious of guessing? Easier said than done.

Teichner asked, “Is it difficult to achieve what you are trying to do? ”

“Quite!” Handmaker responded. “This will be our fifth night in the past two weeks trying to catch birds, and they have eluded us so far.”

By nightfall, the Whimbrel had escaped capture again, and stronger-than-expected tides had flooded all the nets.

The Whimbrel team continued. “This may be our 15th try in the last 4, 5, 6 weeks – I’m losing track, honestly,” Handmaker said. “But, I don’t have high hopes, seeing how hard it has been. These birds are so bright.”

Finally, on May 11, they hit the jackpot – 14 captures. The good news: they managed to tag and put transmitters on two birds. The bad news: a thunderstorm forced them to let go of the rest.

Sanders said: “You know I like the challenge a bit. If it was easy I wouldn’t like it. And I’m glad the birds win. They should!”

Winning, but for how long? Without the work being done here at Deveaux Bank, how long?

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Story produced by Mary Lou Teel. Publisher: David Bhagat.