Citizen scientists help identify shorebird extinction threat

Degradation and destruction of mudflats thousands of kilometres away has contributed to a dramatic decline in the number of migratory shorebirds in Australia, new research shows.

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A critically endangered curlew sandpiper in a mixed flock of migratory shorebirds at Cairns Esplanade in Queensland. Photo: Nick Murray.

Degradation and destruction of mudflats in north-east Asia has contributed to a dramatic decline in the number of migratory shorebirds in Australia, new research shows.

The study, by an international team of citizen scientists and researchers including UNSW’s Dr Nick Murray, found that species of godwit, curlew and sandpiper are among those under threat in Australia, due to the loss of mudflats thousands of kilometres away.

Many species of birds follow the East Asian Australasian Flyway migratory path from their non-breeding grounds in Australia to breeding sites in the Arctic, resting and refuelling along the way in the Yellow Sea between China and South Korea.

“The more a species relies on the disappearing Yellow Sea mudflats, the faster they are declining,” says study first author Assistant Professor Dr Colin Studds of the University of Maryland in the US.

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A flock of whimbrel embarking on migration from the Yalu Jiang nature reserve, North-East Yellow Sea in China, to breeding sites in the Arctic. Photo: Nick Murray.

To reach their conclusions, the researchers analysed citizen science data collected between 1993 and 2012 on 10 key species of shorebird.

"We are indebted to the volunteers across Australia and New Zealand who have counted the number of migratory birds over a period of decades, making this research possible,” says Dr Murray.

“Even though the birds spend only one or two months of the year at the mudflats in the Yellow Sea, our study shows this is the most important factor in determining the decline in their populations.”

In the past 50 years, about 65% of the tidal flats along 4000 kilometres of coastline between China and South Korea have been lost to development.

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Tidal mudflats being reclaimed for coastal development in the Dandong region, North-East Yellow Sea, China. Photo: Nick Murray.

Australia has signed agreements with China, Korea and Japan to protect migratory birds, yet the birds have continued to decline.

“Every country along the migration route of these birds must protect habitat and reduce hunting to prevent the birds declining further or even going extinct,” says study senior author Associate Professor Richard Fuller of the University of Queensland.

“We are particularly excited that China and Korea have recently begun the process of listing parts of the Yellow Sea as World Heritage Sites.”

The study, published in Nature Communications, involved researchers from across Australia and from the US, the UK and New Zealand.