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
Wildlife of Morocco endemic bird species, the northern bald ibis ("Geronticus eremita") occurs here, and there are about 12 globally endangered species; the white-headed duck ("Oxyura leucocephala"), the Balearic shearwater ("Puffinus mauretanicus"), the northern bald ibis, the Egyptian vulture ("Neophron percnopterus"), the lappet-faced vulture ("Torgos tracheliotos"), the hooded vulture ("Necrosyrtes monachus"), the white-backed vulture ("Gyps africanus"), the Rüppell's vulture ("Gyps rueppelli"), the sociable lapwing ("Vanellus gregarius"), the slender-billed curlew ("Numenius tenuirostris"), the great knot ("Calidris tenuirostris") and the saker falcon ("Falco cherrug"). Other birds with restricted ranges in north Africa include the Levaillant's woodpecker ("Picus vaillantii"), the Moussier's redstart ("Phoenicurus moussieri") and the