Virtually as one, the knots all lift from the mudflat, calling out a rallying song.
ON THE OTHER SIDE of Australia, in Broome, a different species of migratory shorebird – the red knot – is preparing to migrate. Across the mudflats, the knots stand in a line spread out east to west as if waiting for a bus. Internally though, they are anything but calm. Even their organs are getting ready. Their gizzard and liver are contracting, and their heart is becoming larger to deal with the physical exertion to come.
Around them, mudskippers flip along, fiddler crabs wave their red claws at each other and other shorebirds scramble, probing the mud. The red knots stand, legs slightly askew, accommodating their newly formed bird-guts. They will use this creamy-yellow, energy-rich fat to fuel their flight to the other side of the world. Virtually as one, the knots all lift from the mudflat, calling out a rallying song. They circle, gaining altitude, and form a wide echelon.
Chris Hassell, an ecologist with the Global Flyway Network, perches on a stool and watches the birds through a telescope. “I’m looking at a red knot there, which is code three, blue lime/blue blue, 50 per cent breeding plumage,” Chris says, noting the details on a clipboard. They flow over the red cliffs of Roebuck Bay, their wings pushing them slowly higher into the sky.
“I will probably see that bird in China,” he says.
WHIMBRELS CIRCLE IN the air. In the meadow below, surrounded by feathered decoys, Jin Weiguo sits, his umbrella propped up behind him, a cut bamboo whistle in his mouth. Weiguo blows the thumb-sized instrument, controlling the sound with his tongue and lips, producing the squeals and trills of shorebirds.
The 57-year-old waits patiently as the birds lose altitude and touch down gingerly. Violently, he pulls a thin rope attached to a long net.The net sails across the grass like a white wave. Caught by surprise, the birds flap and struggle, but cannot escape.
Weiguo, once a hunter, is now a trapper. He learnt to whistle from his father when he was seven and has caught, by his own estimate, tens of thousands of shorebirds in his lifetime. He used to sell them for food, or as pets for children. A piece of string would be tied about their necks and they would be fed rice, Weiguo says.
Now he captures shorebirds on the island of Chongming, 50km from Shanghai, so that researchers can weigh them, measure them, and tag them. His transition from poacher to conservationist could be taken to be emblematic of an increasing concern about the natural environment in China. But the reserve Weiguo works in sits surrounded not by greenways, but by industry and deep seaports.
After a period in hand, the birds are released with their coloured tags. Slightly dazed, they spill into the smog-filled sunlight over the Yangtze River. Hungry godwits, plovers and whimbrels stop here briefly from almost everywhere along the flyway: from Myanmar, Indonesia, India or Australia.
The mudflats here, fed by the Yangtze River, have provided food for birds and locals alike for thousands of years.The Yellow Sea, between China and the Korean Peninsula, produces 20 per cent of the world’s fishery products. It supports endangered finless porpoises, Eurasian otters, largha seals, and millions of migratory shorebirds. Or at least, it used to.
One of the largest shorebirds in the world, the critically endangered eastern curlew winters in the coastal wetlands of Australia.
Global Flyway Network ecologist Chris Hassell on migration watch – for species such as the eastern curlew and red knot – at Roebuck Bay in Broome, WA.