31-7-2026 COBH HARBOUR, IRELAND - GREAT BLACK BACKED GULL (Larus marinus)

The Great Black-backed Gull (Larus marinus), often referred to as the "king of the Atlantic waterfront," is the largest member of the gull family. This imposing bird is characterized by its white head, neck, and underparts, contrasting with its dark grey wings and back. The pink legs and yellow bill, with a hint of orange or red near the tip, complete its striking appearance.

Adults are easily identified by their sheer size, dark grey to blackish upper-wings, and white "mirrors" at the wing tips. The bill is robust and yellow, with a red spot near the tip of the lower mandible. Juveniles display a mottled black-brown pattern with a white tail featuring dark bars and spots at the base. They undergo a gradual transition to adult plumage over four years.

The Great Black-backed Gull frequents a variety of coastal environments, including rocky shores, sandy beaches, and estuaries. It is also found inland near lakes, ponds, rivers, and wet fields. This species is adaptable and can be seen at refuse dumps and dredge spoils, especially in New Jersey.

Great black-backed gulls are opportunistic feeders, apex predators of the oceanic sky, and are very curious. They will investigate any small organism they encounter and will readily eat almost anything that they can swallow. They get much of their dietary energy from scavenging, with refuse, most provided directly by humans, locally constituting more than half of their diet. The proliferation of garbage or refuse dumps has become a major attractant to this and all other non-specialised gull species in its range. A study to investigate how much time they spend foraging at refuse dumps in Massachusetts found great black-backed gulls were only observed actively foraging 19% of their time there, eating less garbage than other common gulls, and spent most of their time roosting or loafing.

Like most gulls, great black-backed gulls regularly capture fish, and any fish smaller than themselves found close to the surface of the water are potential prey. Stomach contents of great black-backed gulls usually show fish to be the primary food. On Sable Island in Nova Scotia, 25% of the stomach contents consisted of fish, but 96% of the regurgitations given to young consisted of fish. Similarly, on Great Island in Newfoundland, 25% of the stomach contents were fish but 68% of regurgitants were fish.

1-8-2025 STAVANGER PORT, NORWAY - GREAT BLACK BACKED GULL (Larus marinus)

The Great Black-backed Gull (Larus marinus), often referred to as the "king of the Atlantic waterfront," is the largest member of the gull family. This imposing bird is characterized by its white head, neck, and underparts, contrasting with its dark grey wings and back. The pink legs and yellow bill, with a hint of orange or red near the tip, complete its striking appearance.

Adults are easily identified by their sheer size, dark grey to blackish upper-wings, and white "mirrors" at the wing tips. The bill is robust and yellow, with a red spot near the tip of the lower mandible. Juveniles display a mottled black-brown pattern with a white tail featuring dark bars and spots at the base. They undergo a gradual transition to adult plumage over four years.

The Great Black-backed Gull frequents a variety of coastal environments, including rocky shores, sandy beaches, and estuaries. It is also found inland near lakes, ponds, rivers, and wet fields. This species is adaptable and can be seen at refuse dumps and dredge spoils, especially in New Jersey.

Breeding along the coasts and islands of the North Atlantic, this gull's range extends from the northwest of Russia through Scandinavia, the Baltic Sea coasts, to northwestern France, the UK, and Ireland. Across the Atlantic, it is found in Iceland, the Faroe Islands, southern Greenland, and the Atlantic coasts of Canada and the United States. Some populations migrate southward in winter, reaching as far as the Caribbean and northern South America.

The Great Black-backed Gull is sedentary, with some individuals moving south or inland during winter. It is a dominant and aggressive bird, often seen scavenging or kleptoparasitizing other birds. This gull is also known for its predatory habits, hunting a wide range of prey from fish to other seabirds. for its predatory habits, hunting a wide range of prey from fish to other seabirds.

6-10-2024 TARBERT ISLAND, IRELAND - GREAT BLACK BACKED GULL (Larus marinus)

The Great black-backed gull (Larus marinus ) is the largest member of the gull family. Described by the Cornell Lab of Ornithology as "the king of the Atlantic waterfront", it is a very aggressive hunter, pirate, and scavenger.

The Great black-backed gull is 64–79 cm (25–31 in) long with a 1.5–1.7 m (4 ft 11 in – 5 ft 7 in) wingspan and a body weight of 0.75–2.3 kg (1 lb 10 oz – 5 lb 1 oz).

The adult Great black-backed gull is fairly distinctive, as no other very large gull with blackish coloration on its upper wings generally occurs in the North Atlantic. In other white-headed North Atlantic gulls, the mantle is generally a lighter gray color and, in some species, it is a light powdery color or even pinkish. It is grayish-black on the wings and back, with conspicuous, contrasting white "mirrors" at the wing tips. The legs are pinkish, and the bill is yellow or yellow-pink with some orange or red near the tip of the lower bill.

Juvenile birds under a year old have scaly, checkered black-brown upper parts, the head and underparts streaked with gray-brown, and a neat wing pattern. The face and nape are paler and the wing flight feathers are blackish-brown. The juvenile's tail is white with zigzag bars and spots at the base and a broken blackish band near the tip. The bill of the juvenile is brownish-black with a white tip and the legs are dark bluish-gray with some pink tones. As the young gull ages, the gray-brown coloration gradually fades to more contrasting plumage and the bill darkens to black before growing paler. By the third year, the young gulls resemble a streakier, dirtier-looking version of the adult. They take at least four years to reach maturity, development in this species being somewhat slower than that of other large gulls.