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
Hutton's shearwater a white underbelly and brown collar, dark borders to the underwing, dark grey bill, and pinkish dark-webbed feet; it can be distinguished from fluttering shearwater by its dark grey "armpits". At a breeding colony it has a loud cackling call. Hutton's shearwater feeds in the open ocean largely on small fish and krill, diving up to 20 m. "Puffinus huttoni" have long bills, which are adapted to catch prey more or less underwater by plunging from a few meters above the surface or by paddling slowly forwards searching with their head submerged, then diving using partly opened wings for propulsion.