Skellig Michael classified as a Special Protection Area in 1986, when they were recognised for containing both an usually large variety and population of birds. It is known as an eyrie for Peregrine Falcon. Other birds of interest include Fulmar, Manx shearwater ("Puffinus puffinus"), Storm petrel, Gannet, Kittiwake, Guillemot and Atlantic Puffin. A herd of goats lived on the island until recently, and it supports a population of rabbits and house mice, both relatively recent introductions, probably introduced in the 19th century by lighthouse attendants. Grey Seal haul out on the island's ledges. The word "Skellig" derives from the old Irish word
Christmas shearwater and introduced black rats took eggs and chicks. In 1985, the population on Sala-y-Gómez, a nature sanctuary, was estimated at 5,000. With its wide range and considerable numbers, the Christmas shearwater is considered a species of least concern by the IUCN. Christmas shearwater The Christmas shearwater ("Puffinus nativitatis") is a medium-sized shearwater of the tropical Central Pacific. It is a poorly known species due to its remote nesting habits, and it has not been extensively studied at sea either. It is one member of a very ancient lineage of the small "Puffinus" species. Its only close living relative is the