The Manx shearwater has a remarkable life. After fledging the young birds migrate to the South Atlantic off the coasts of Brazil and Argentina. They remain there at sea for five years before returning to breed on their natal island. On their return they navigate back to within a few metres of the burrow in which they were born. As they are ungainly and vulnerable on the land, they leave their burrows at dawn for the fishing grounds some fifty kilometres north out in the Irish Sea, not returning until dusk. Thus they attempt to avoid the gulls to which they would fall easy prey.