Migratory Shorebirds Vanishing Along the East Asian-Australasian Flyway

But a new study shows that these migrants and Australia's one million resident shorebirds have suffered a serious long-term decline in numbers over the past 25 years.

Great knots and bar-tailed godwits at 80 Mile Beach, Australia (Photo by Warren Utting courtesy Benthics and Birds)

A large scale aerial survey study covering the eastern third of the continent by researchers at the University of New South Wales has identified that migratory shorebirds populations there plunged by 73 percent between 1983 and 2006, while Australia's 15 species of resident shorebirds - such as avocets and stilts - have declined by 81 percent.

The first long-term analysis of shorebird populations and health at an almost a continental scale, the study is published in the scientific journal "Biological Conservation."

"This is a truly alarming result: in effect, three-quarters of eastern Australia's millions of resident and migratory shorebirds have disappeared in just one generation," says an author of the report, Professor Richard Kingsford.

"The wetlands and resting places that they rely on for food and recuperation are shrinking virtually all the way along their migration path, from Australia through Indonesia, the Philippines, Malaysia and up through Asia into China and Russia," Kingsford said.

The study reveals for the first time that Australia's inland wetlands are particularly important for migratory shorebirds, along with the better-known coastal sites such as Roebuck Bay, Port Phillip Bay, the Hunter River estuary and Hervey Bay.

"Loss of wetlands due to river regulation is one of the more significant contributors to this drastic decline, but it appears such a threat is largely unrecognized in Australia's conservation plans and international agreements," says Professor Kingsford, who co-authored the report with Silke Nebel and John Porter, of the University of New South Wales School of Biological, Earth and Environmental Sciences.

"Our grandchildren will not be able to share in the excitement of marvelling at the migratory feats of shorebirds if the current decline continues," said Dr. Graeme Hamilton, CEO of Birds Australia, the BirdLife International partner organization in Australia.

The study comes as nearly two million migratory shorebirds are gathering in what has been described as one of the world's greatest wildlife spectacles.

Bar-tailed Godwit during a migratory journey along the East Asian-Australasian Flyway. (Photo by Dave Bakewell courtesy Birdlife International)

Many birds have already set off - including a bar-tailed godwit carrying a small transmitter. The GPS tag allows researchers to follow its route from Broome in northwestern Australia as it travels to breeding grounds in Alaska. The bird 'H8' was last sighted on April 11 entering the Yellow Sea in China, after traveling around 5,000 km (3,000 miles).

The Bar-tailed Godwit tracking study is part of the Pacific Shorebird Migration Project; involving biologists from the California-based PRBO Conservation Science and the U.S. Geological Survey's Alaska Science Centre, as well as Massey University and the University of Auckland, both based in New Zealand.

The Yellow Sea provides rich feeding habitat for more than three million migratory birds annually, and is a key refuelling stop. A total of 36 species pause here to rebuild their energy reserves before continuing on their migrations.

The Yellow Sea is also home to 600 million people in China and South Korea - about 10 percent of the world's population. The demands of this growing human population are destroying the tidal feeding grounds, crucial for migratory shorebirds.

"Destruction of habitat along the East Asian-Australasian Flyway is a major threat as birds are most vulnerable during their migration," said Simba Chan, senior conservation manager at BirdLife's Asia Division

The most important shorebird site within the Yellow Sea, Saemangeum, now is being reclaimed for development, putting millions of migratory birds under threat.

A dunlin falls exhausted from the sky at Seamangeum, South Korea. (Photo courtesy Pacific Spirit Marine Institute)

The 40,100 hectare construction project on the west coast of South Korea involves damming the estuaries of the Mangyeung and Dongjin Rivers with a seawall 33 km (20 miles) long.

"Our international agreements relating to shorebird conservation, such as the Ramsar Convention, the Japan-Australia Migratory Bird Agreement, the China-Australia Migratory Bird Agreement, and the Convention on the Conservation of Migratory Species of Wild Animals, do not seem to be working," warns Dr. Hamilton.

A worldwide assessment of the survival status of all bird species will be released on May 19. Published once every four years, the 2008 IUCN Red List of Threatened Species for birds is a global assessment of every bird species on Earth.

For birds, the IUCN Red List is maintained by BirdLife International. The last assessment showed one in eight of the world's 10,000 bird species are at risk of extinction.

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