A pure white petrel that lives at the edge of the ice. It is a ghost against the glaciers. A snowflake with wings. The snow petrel is one of the most beautiful birds in Antarctica. It is also one of the most inaccessible. It breeds on cliffs that humans rarely visit. The crevices require ropes to reach. The isolation is absolute. The location is extreme. The plumage is entirely white. It looks like fresh snow on a windless morning. The eye is dark. It is a small black bead in a field of white. The bill is black. This is the only other colour. In flight the bird is almost invisible against the ice and clouds. Predators cannot see it. The camouflage is perfect. The concealment is total. The survival depends on it. Feeding involves small fish squid and krill. The bird picks them from the surface of freezing water. It follows ships. It scavenges scraps and offal. A snow petrel feeding is a white speck on a white sea. The contrast is minimal. The detection is difficult. The effort is constant. The hunger is persistent. Flight is buoyant and tern-like. Rapid wingbeats alternate with long glides. A snow petrel in a blizzard is in its element. It is completely invisible against the blowing snow. The weather is not an obstacle. It is a cover. The bird uses the storm. It does not hide from it. It merges with it. Breeding takes place on Antarctic cliffs. These are sometimes hundreds of kilometres from open sea. The nest is a crevice or hole among rocks. A single white egg is laid. Both parents share incubation duties. The chick is covered in white down. It is equally invisible against the snow. The vulnerability is high. The protection is visual. The strategy works. In New Zealand these birds are rare vagrants. They are occasionally seen around the subantarctic islands. Storms blow them north. The occurrence is infrequent. The distance is significant. The presence is accidental. This is one of the few birds that lives its entire life in Antarctica. It breeds there. It feeds there. It never leaves. The commitment is total. The range is restricted. The adaptation is complete. The bird belongs to the ice. The population is large. Millions of birds exist. They are scattered around the Antarctic coast. The distribution is wide. The numbers are significant. The species is secure. For now. Climate change is a growing threat. Warming temperatures reduce sea ice. Less ice means fewer krill. These gather under the ice. The snow petrel may struggle as the planet warms. The consequence is indirect. The impact is severe. The future is uncertain. The dependency is critical. The call is a soft chattering 'che-che-che'. It is often given at the colony. In the vast silence of Antarctica the sound carries for kilometres. The noise is faint. The distance is great. The presence is marked. The communication is simple. It persists. The bird calls. The ice answers. Nothing else does.