Masatierra petrel spends the greatest part of the year at sea in the eastern Pacific Ocean south of the equator where the Humboldt Current causes a major
upwelling of nutrient-rich cold water. Here the bird feeds by skimming across the surface of the water and scooping up
prey on the wing. It nests in two island groups off the coast of Chile. On the
Desventuradas Islands, the largest
colony is on San Ambrosio where more than 10,000 birds were estimated to be present in 1970. San Félix also had 150 to 200 nesting pairs at that time. On the
Juan Fernández Islands, the bird is no longer believed to be nesting on
Robinson Crusoe Island but
Santa Clara Island had a few hundred birds present in 1991, a number not likely to increase because there is limited availability of suitable nesting sites on the island. ==Status==