Best experienced with sound turned on

For millennia, the skies have filled each spring and fall with migrating flocks.

But now the skies are emptying.

Special report

The planet’s most threatened flight path, and the $3 billion plan to protect it

Best experienced with sound

Unmute Mute

Credit: The Hong Kong Bird Watching Society, World Heritage Promotion Team of Korean Tidal Flats, Royal Society for the Protection of Birds, Wich'yanan Limparungpatthanakij/Macaulay Library

A large flock of knot flying over Snettisham in the UK. Credit: Royal Society for the Protection of Birds (RSPB)

Patricia Zurita CEO of BirdLife International, a global conservation organization

A flock of birds, mostly bar-tailed godwit, in Queensland, Australia. Credit: Michael Daley/Macaulay Library


Birds at the Yellow River Delta wetlands in Dongying, Shandong Province of China. Credit: Zhou Guangxue/VCG/Getty Images

Korea’s tidal flats are important to migratory birds as well as local people who use traditional methods to harvest shellfish from the mudflats. Credit: World Heritage Promotion Team of Korean Tidal Flats

Migratory bird populations along the flyway are plummeting, pushing some species towards the brink of extinction. In East Asia, more than half of waterbird species, which depend on wetlands for survival, are in decline.


Plan for protection In October 2021, a $3 billion initiative was launched to protect and restore wetlands along the flyway.

The Regional Flyway Initiative, created by BirdLife International, along with the Asian Development Bank and the East Asian-Australasian Flyway Partnership (a mixture of governments and non-profits), will work with local partners and communities to coordinate conservation efforts.

It aims to save not only the birds but also the critical wetlands that 200 million people depend on for their livelihoods and which provide vital protection from sea-level rise.


A male bar-tailed godwit in Alaska during breeding season. Credit: D. Ruthrauff/USGS / Sound credit: William V. Ward/Macaulay Library

A bird’s-eye view of the flyway
Bar-tailed godwit
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Bar-tailed godwits in Queensland, Australia. Credit: Terence Alexander/Macaulay Library

Bar-tailed godwit One hero of the East Asian-Australasian Flyway is the bar-tailed godwit. The tawny bird may look unassuming, but its annual migration is nothing less than remarkable.

An embodiment of endurance, the baueri subspecies of the bar-tailed godwit holds the world record for the longest non-stop bird flight – traversing over 13,000 kilometers (8,078 miles) across the Pacific Ocean in 239 hours, or just under 10 days.

Journey overview
Bar-tailed godwit

Note: This is a generalized route based on tracking data from multiple bar-tailed godwits.

Source: Massey University/Global Flyway Network


Credit: Google Earth Pro


Bar-tailed godwits feeding in Alaska before migration. Credit: Jan van de Kam


A flock of bar-tailed godwits in Alaska. Credit: D. Ruthrauff/USGS

Pre migration in Alaska
Arrival in new zealand

Credit: Pre migration photo: Jan van de Kam / Arrival photo: Phil Battley/Massey University


Credit: Google Earth Pro


A flock of bar-tailed godwits near Auckland, New Zealand. Credit: Jan van de Kam


Correction: An earlier version of this map incorrectly labelled Dayang River. The map has also been updated to use the East Asian-Australasian Flyway Partnership’s coordinates for the Yalu Jiang Nature Reserve.

Credit: Google Earth Pro, EAAFP

Ding Li Yong BirdLife’s regional coordinator for the Asia-Pacific region

Bar-tailed godwits gather at the Yalu Jiang Nature Reserve during their northern migration. Credit: Ding Li Yong


Bar-tailed godwits and other shorebirds at the Yalu Jiang Nature Reserve. Credit: Jan van de Kam

Bar-tailed godwit numbers are decreasing

Population estimate of the baueri subspecies of the bar-tailed godwit, based on data collected in Australia and New Zealand.

Source: Nature Communications

Birds spotted at tidal flats (Getbol) on the southwest coast of Korea. Credit: World Heritage Promotion Team of Korean Tidal Flats

Yukon-Kuskokwim Delta, Alaska Its epic journey begins in the Yukon-Kuskokwim delta on the west coast of Alaska. Godwits arrive here in late May, when the snow has melted and the hilly Arctic tundra provides cover for nesting, and berries to forage. They lay their eggs and after a few months, leave their fledglings to head south for a warmer climate.

Before setting off to the other end of the world they “bulk up” – feasting to the point that nearly half their body weight is pure fat, which they burn off when they fly. A female bird (heavier than its male counterpart) almost doubles in weight pre-migration – going from an average of 300 grams to 555 grams.

Scientists still puzzle over their sense of direction, suggesting they use a combination of stars, landforms, smells and the Earth’s magnetic field to get from A to B.

With wings beating day and night, and averaging 56 kilometers (35 miles) per hour, it’s thought that the bar-tailed godwits don’t sleep or eat during the journey.

After eight to 10 days, they arrive in New Zealand, exhausted and almost unrecognizably scrawny – their wings drooping.

Nelson, new zealand Some towns and cities, such as Nelson and Christchurch (before the cathedral spire was destroyed in an earthquake), traditionally welcome the flocks with the chimes of church bells.

They rest up here for the winter months, and then embark on their return journey around March.

Yalu Jiang Nature Reserve, Yellow Sea This time, they cross over Asia, allowing themselves a month-long stop around the Yellow Sea. One popular site is the Yalu Jiang Nature Reserve in China.

Almost the entire baueri subspecies is believed to pass through the area each spring.

But even this is not on the scale it used to be. David Melville, ornithologist and co-author of a 2018 report on shorebirds in the Yellow Sea, says that since 2013, food stocks have crashed at Yalu Jiang and the number of bar-tailed godwits has declined dramatically.

He says this could be linked to the development of a port nearby, which has diverted freshwater flow causing clams – a stock food for birds like the godwit – to disappear.

The entire species is suffering as a result of human development, with populations of the baueri subspecies declining across the whole flyway.

Yellow seaSadly, it’s not an isolated example. The Yellow Sea is a critical stopover for a number of migratory waterbirds, as its coastal mudflats – formed by sediments deposited from the Yangtze and Yellow Rivers – are rich with food. But these areas are being lost at an alarming rate.

In the past 50 years, 65% of the wetlands around the Yellow Sea have been degraded or lost due to reclamation, pollution and sea-level rise.

A race against time
Spoon-billed sandpiper
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The spoon-billed sandpiper, a tiny shorebird with a black bill like a spatula, shows the impact this can have on a species. Teetering on the edge of extinction, there are fewer than 800 spoon-billed sandpipers left in the world.

In northeast Russia, the spoon-billed sandpiper has dramatically declined

Population estimates of spoon-billed sandpiper pairs between 2003 and 2021 in the Meinypilgyno region of Russia.

Source: Spoon-billed Sandpiper Task Force

They breed in northeast Russia and winter in South East Asia, refueling at sites on the Yellow Sea along the way. One such site is Saemangeum, in South Korea, where more than 100 spoonies (as they are affectionately called) used to gather each year, according to a 2016 report on shorebird declines.

But in the 1990s, construction began on a 33-kilometer-long seawall across the tidal flat, which was completed in 2006, and much of the area is still being converted into either agricultural or industrial land.

Since then, just a handful of spoon-billed sandpipers have been spotted there, says Nial Moores, director of Birds Korea.

Construction of the Saemangeum seawall began in 1991, altering the nature of the tidal flat

Credit: Google Earth Pro

But conservation can and does make a difference
Black-faced spoonbill

Take the black-faced spoonbill, a large, white wading bird found only in East Asia, with a long spoon-like beak that it scrapes along the shallows for food.

The population reached its nadir in the 1990s, with only a few hundred birds remaining. But protecting nesting sites and restoring breeding and wintering grounds has helped the species regain its numbers.

In 2022, more than 6,000 black-faced spoonbills were recorded.

Black-faced spoonbill numbers have rebounded

Global population of black-faced spoonbills.

Source: Hong Kong Bird Watching Society

Patricia Zurita CEO of BirdLife International, a global conservation organization

Tidal flats in Korea. Credit: World Heritage Promotion Team of Korean Tidal Flats

Zurita hopes that the Regional Flyway Initiative will help both birds and biodiversity bounce back.

First, it plans to focus on restoring 50 of the most critical wetlands along the route. While these locations are still being determined, BirdLife has mapped a longlist of potential sites – many of which are centered on the Yellow Sea.

Potential sites of the Regional Flyway Initiative

  • East Asian-Australasian Flyway
  • Potential initiative sites

Source: BirdLife International

Patricia Zurita CEO of BirdLife International, a global conservation organization

The Yellow River Estuary nature reserve in Dongying, China, is a hotspot for wild birds. Credit: Costfoto/Future Publishing/Getty Images

Patricia Zurita CEO of BirdLife International, a global conservation organization

A flock of backbill snipes forages in the coastal wetlands of China's Jiangsu province. Credit: Costfoto/Future Publishing/Getty Images

A pilot project in China’s Yancheng Wetlands shows the potential scale of success. The area had been heavily degraded due to urbanization and pollution, but by creating nature reserves and forest farms, more than 45 square kilometers of wetlands has now been restored, according to the Asian Development Bank (ADB).

Waterbird populations have skyrocketed as a result, with one reserve recording more than triple the number of birds at the site in 2018 compared with two years earlier, and almost 3,000 jobs in ecotourism, sustainable fishing and agriculture have been created, the bank says. In 2019, the Yancheng Wetlands were listed as a UNESCO World Heritage natural site – a prestigious title that will help to further protect the area.

But there are still challenges. The mission relies on the buy-in of governments from more than 22 countries — many with different languages, cultures and political situations — and continued funding from both public and private donors.

This is where the ADB comes in. A huge institution accustomed to handing out loans for big infrastructure projects, such as railways or power stations, it has relationships with ministries of finance around the continent.

“Our goal in this project is to link those ministries and persuade them that they need to invest in nature,” says Duncan Lang, senior environment specialist at the ADB.

The Mai Po Nature Reserve in Hong Kong, with Shenzen City rising up behind. Credit: Martin Harvey/Getty Images

There’s an economic incentive for governments, he adds. Wetlands act as natural sponges, protecting areas from flooding and storm surges, and they are carbon stores. “The money that they invest is paid back by the money they don’t have to pay in storm damage,” and potential carbon savings could contribute to a nation’s climate pledges, says Lang.

By showing that preserving nature can make financial sense, Zurita believes this initiative could become a blueprint for conservation across the world. She says BirdLife has already had interest from development banks on other continents wanting to protect their flyways.

Birds fly from pole to pole across every continent on Earth. They are seen as the proverbial “canary in the coal mine” – indicators of ecological health. And their decline is sending a message that the natural world is in danger.

Protecting their flight paths could help to preserve ecosystems across the whole planet.

Patricia Zurita CEO of BirdLife International, a global conservation organization

Birds flying over Korea's tidal flats. Credit: World Heritage Promotion Team of Korean Tidal Flats

What you can do to help

Patricia Zurita

Patricia Zurita Call to Earth guest editor, CEO of BirdLife International, a global conservation organization

spread the word

“Most people don’t even know this is actually happening, and it’s so far away from their day to day, that unless we let people know that this is a problem, we’re not going to be able to change anything.”

Give nature a home

“Remember that we are part of millions of species on this planet, and provide homes and food to birds that are coming your way.”

Buy local and use less energy

“Think about things that you’re buying and the way that you’re transporting yourself. The more energy that I use – the more gas, the more oil and the more petrol I’m using – the more climate change is happening. And the more nature is actually suffering.”

You can take action now

Migratory birds around the world are in danger, but there are things we can do to help. Start by spreading the word.