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
Procellariidae been implicated in (but not proved to have caused) the expansion in range of the northern fulmar in the Atlantic. Three of the six prion species have bills filled with lamellae, which act as filters to sift zooplankton from the water. Water is forced through the lamellae and small prey items are collected. This technique is often used in conjunction with a method known as hydroplaning where the bird dips its bill beneath the surface and propels itself forward with wings and feet as if walking on the water. Many of the shearwaters in the genus "Puffinus" and "Ardenna" are