White-tailed eagle only from the mainland. Also Rùm hosts large seabird colonies that make for viable prey, including eider, shag ("Phalacrocorax aristotelis"), auks and gulls; as well as one of the few in Britain of manx shearwater ("Puffinus puffinus"). Furthermore, mainly as a source of carrion, were a population of around 1500 red deer and 200 feral goats; otters and gulls were also numerous and available to kleptoparasitize. The birds to be used for reintroduction were gathered as nestlings from western Norway, as this is the nearest native breeding population. The young eagles were either kept in high grade fowl cages or
San Benedicto Island location where several seabirds of the tropical Eastern Pacific come to breed. Taxa breeding on San Benedicto are: The nearly extinct Townsend's shearwater ("Puffinus auricularis") does not seem to breed on San Benedicto, but can sometimes be seen feeding offshore. Given that there are no invasive species on San Benedicto and also no predators apart from the frigatebirds, the island might be highly suitable for establishing a new colony. Indeed, it bred here before the 1952 eruption; shearwaters are highly conservative in choosing their breeding locations, which explains why San Benedicto has not yet been recolonized. Vagrants of other species,