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
Saba (IBA AN006 "Saba Coastline") by BirdLife International. Saba is home to about sixty species of birds, many of which are sea birds that use the holes and crevices of the steep cliffs and two small islands for breeding and feed in the waters around the island. Saba’s shoreline is home to the Caribbean’s largest breeding colony of Red-billed tropicbird ("Phaethon aethereus"). The Audubon's Shearwater ("Puffinus lherminieri") is another common bird, and is the national bird of Saba as well as being featured on their coat of arms. Being an island, Saba is home to a number of endemic species including