Bar-tailed godwits flying from New Zealand and Australia to Siberia and Alaska stop at the Yalu River in southeast China to refuel.
In April every year, thousands of bar-tailed godwits flying from New Zealand and Australia to Siberia and Alaska stop at the Yalu River in southeast China to refuel. After foraging for three weeks, they will continue their migration northward to Siberia and Alaska for breeding.
"Their weight will be doubled, but they maintain the same body size by compressing their internal organs. They compress their internal space as much as they can to increase body fat, so they can sustain themselves during the long trip," said Wang Xiaofei from Yalu River Delta Seashore Wetland Estuary Nature Reserves.
Bar-tailed godwits are known as one of the greatest of all the bird world's global travelers. In 2007, researchers attached a GPS tracker to a bar-tailed godwit in Alaska and found that she made a non-stop journey back to New Zealand, taking nine days to travel 11,700 kilometers.
That broke all previous distance records held by birds.
However, a new global study shows a decline in the number of these migratory birds is likely a result of degrading coastal mudflats in northeast Asia.
Bird Life Tasmania convener Eric Woehler has co-authored a study, which outlines how shorebirds depend on healthy coastlines on the Yellow Sea between China and South Korea as stop-off points as they migrate.
"Every country along the migration route of these birds must protect habitat and reduce hunting to prevent the species heading to extinction. Scientists have long believed that loss of these rest stops could be related to the declines, but there was no smoking gun," Dr Woehler said.