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
Flesh-footed shearwater Flesh-footed shearwater The flesh-footed shearwater ("Ardenna carneipes"; formerly "Puffinus carneipes") is a medium-sized shearwater. Its plumage is black. It has pale pinkish feet, and a pale bill with a distinct black tip. Together with the equally light-billed pink-footed shearwater, it forms the "Hemipuffinus" group, a superspecies which may or may not have an Atlantic relative in the great shearwater. These are large shearwaters which are among those that have been separated in the genus "Ardenna". It breeds in colonies, and has two main breeding areas: one in the southwest Pacific Ocean includes Lord Howe Island (16,900 pairs ), South Australia