The eastern curlew is the largest shorebird in the world, and it is in trouble. It is a massive wader with a bill that looks like it belongs on a different bird entirely. The bill curves downward, long and slender, measuring up to twenty centimetres. That is longer than the rest of the bird's head. It is a specialised tool for a specialised diet. The plumage is streaked brown and buff, well camouflaged against the mud. The legs are long and grey. In flight, the lower back is white and the underwings are barred. It is a big, heavy bird on the wing. It flies with deep, slow wingbeats. It does not look fast. It crosses oceans anyway. Feeding involves probing deep into soft mud with that extraordinary bill. The tip is sensitive, feeling for prey below the surface. The bird targets crabs, molluscs, and worms. An eastern curlew feeding is patient. It probes, pauses, and probes again. It does not rush. On breeding grounds, it also takes insects and berries. The call is a loud, ringing "cur-lew," repeated several times. The sound carries across the mudflats. On a quiet estuary, you can hear an eastern curlew from a kilometre away. The bird is not hiding. It announces its presence. In New Zealand, these birds are rare but regular visitors. They arrive in spring and leave in autumn. A few hundred birds each year scatter around the coast. They prefer the north: the Firth of Thames, Kaipara Harbour, and Whangarei Harbour. A bird that has come a long way to find a quiet mudflat. The migration route is epic. Eastern curlews breed in Siberia and northern China. They fly south along the East Asian-Australasian Flyway. They stop in the Yellow Sea to refuel, doubling their body weight before continuing. Then they reach Australia and New Zealand. A one-way trip covers 15,000 kilometres. The population is crashing. The Yellow Sea mudflats, critical for migration stopovers, have been reclaimed for industry and agriculture. The birds arrive. The mud is gone. They starve. Conservationists are working on the problem. Protected areas are being established in the Yellow Sea. International agreements are being signed. The curlew keeps declining anyway. It may vanish before the solutions arrive. The numbers are not encouraging. Hunting in some countries adds to the pressure. Climate change affects breeding habitat in the north. The eastern curlew was once confused with the far eastern curlew. Same species. Different name. The confusion does not matter now. The bird just needs somewhere to land. The global population is estimated at 30,000 to 40,000 birds and declining sharply. The International Union for Conservation of Nature classifies the species as Endangered. In New Zealand, it is classified as Nationally Critical by the Department of Conservation. The status reflects the severity of the threat. The flyway is failing. The birds are losing their way.