The Sooty Shearwater is one of the most common seabirds in the world and easily the most common member of its genus. They breed in enormous colonies in both the south Pacific and Atlantic Oceans on islands off southeast Australia, New Zealand and Tierra del Fuego (South America) where certain breeding congregations can exceed 2.5 million pairs. When not breeding the Sooty Shearwater embarks upon one of largest mass migrations known. Shortly after fledging the population begins to move towards the northwest corner of their respective oceans and following the prevailing winds, eventually move to the east arriving in western North America and Europe late in the local summer. From there they move south back to their breeding grounds. The species is also the only shearwater that can be legally harvested in New Zealand, with the native Maoris taking up to 250,000 chicks for food, soap and oil.