A bird that lives on the edge of extinction and seems to know it. The Chatham Island oystercatcher is not doing well. A few hundred birds remain. They are scattered around the Chatham Islands. They hold on to beaches and rocky shores that humans have only recently started sharing. The bird does not thrive in company. It needs space. There is not much space left. The constraint is physical. The pressure is constant. It looks like most other oystercatchers. Black head, black upperparts, white belly. A long red bill and pink legs complete the look. The difference is subtle. It has a white shoulder patch that extends onto the inner wing. In flight, that patch is visible. On the ground, it is not. The birds are wary. They take flight before you get close enough to see details. The distance is maintained. The observation is brief. It feeds on molluscs, worms, and small crustaceans. It probes the sand. It smashes open shellfish with its heavy bill. The bill is a specialised tool. It pries, hammers, and slices. An oystercatcher without its bill is not an oystercatcher. The tool defines the function. The function defines the survival. The bird uses what it has. It does not improvise. Breeding takes it to sandspits and coastal dunes. The nest is a shallow scrape. It is lined with shells and pebbles. Two or three eggs are laid. Both parents share incubation. The defence is aggressive. A Chatham oystercatcher defending its nest will dive at intruders. It screams. It feigns injury to draw predators away. The performance is theatrical. The intent is serious. It protects the future. The threats are many. Introduced predators include cats, rats, and hedgehogs. Disturbance from livestock and vehicles adds pressure. Coastal development reduces habitat. Sea level rise threatens the margins. A species with a tiny population cannot afford any of them. The margin for error is zero. The risk is cumulative. The bird persists despite the odds. Conservationists have been working on the Chathams for decades. Predator control helps. Nest protection helps. Public awareness helps. The population has stabilised. It is slowly increasing. But "slowly increasing" from a base of three hundred birds is not a victory. It is a holding action. The effort is continuous. The result is fragile. The bird relies on intervention. It cannot survive alone. The chicks are mobile within hours of hatching. They follow the parents. They peck at the ground. They learn to open shells. They are covered in grey down. This camouflages them against the sand. A predator walking past might not see them. That is the hope. The camouflage is effective. The vulnerability remains. The chicks grow fast. They need to. The call is a loud, ringing whistle. It is repeated in alarm. On a quiet beach on the Chathams, a tōrea tai calling means something is wrong. A cat. A person. A vehicle. The bird sees it. It warns the others. Then it flies. The sound marks the threat. It signals danger. It carries on.