Chatham oystercatcher
This bird is threatened because human beings change the places it lives.  Human beings changed the islands to make farmland, and they put marram grass on the sand dunes, which changes the way the sand flows.  The dunes are steeper, so the birds must build nests closer to the water, and sometimes the high tide takes the eggs away.  Humans also brought new animals to the islands in the 1800s: cats eat eggs and chicks, and weka eat eggs.