Great black-backed gull stomach contents of great black-backed gulls was made up of birds, while a further 17% of stomach contents was made up of tern eggs alone. Adult or fledged juveniles of various bird species have also been predaceously attacked. Some fully-fledged or adult birds observed to be hunted in flight or on the ground by great black-backed gulls have included "Anas" ducks, ruddy ducks ("Oxyura jamaicensis"), buffleheads ("Bucephala albeola"), Manx shearwaters ("Puffinus puffinus"), pied-billed grebes ("Podilymbus podiceps"), common moorhens ("Gallinula chloropus"), terns, Atlantic puffins ("Fratercula arctica"), coots ("Fulica" ssp.), glossy ibises ("Plegadis falcinellus"), rock pigeons ("Columba livia") and even predatory birds
Bannerman's shearwater to feed on fish, squid and cephalopods, by surface-seizing, underwater pursuit, including diving and plunging, and pattering (del Hoyo et al. 1992, Brooke 2004). It is likely to nest in rock crevices or burrows and form colonies (del Hoyo et al. 1992). Bannerman's shearwater Bannerman's shearwater ("Puffinus bannermani") is a seabird in the Procellariidae family formerly considered conspecific with Audubon's shearwater ("Puffinus lherminieri"). Little is known of this species other than that it breeds in the Volcano Islands in the Ogasawara Group to the southwest of Japan and doesn't seem to range far from this area. The species population size