Larus marinus
The Great Black-backed Gull is the world’s largest gull and one formidable seabird. This impressive species lives and breeds along Northern Hemisphere shores on both sides of the Atlantic.
The Great Black-backed Gull is a large, eye-catching seabird with a black back and upper wings and pure white head, neck, tail, and underparts. They have pale pink legs and a bright yellow bill with a red spot toward the tip. Their piercing pale eyes are surrounded by a red eyelid.
In flight, white edges are visible around the upper side of the wings, as well as a large white spot at the tips. The underside of each wing is white, with darker flight feathers. The sexes have similar plumage, although females are smaller.
Juvenile Great Black-backed Gulls take about four years to attain their adult plumage. They are pale mottled brownish, with pale legs but dark bills and eyes. Their wings and backs are darker with a checkered appearance.
Apart from their larger size, these gulls appear similar to other Larus species like the Herring Gull (gray back) and Lesser Black-backed Gull (yellow legs).
Adult Great Black-backed Gull
Juvenile Great Black-backed Gull
The Great Black-backed Gull is a massive seabird and the largest gull species in the world. Males are typically larger in all respects.
25 to 30 inches or 64 to 78 centimeters.
Most adults weigh 2.9 to 4.4 pounds or 1.3 to 2 kilograms. The largest males reach 5 pounds or 2.27 kilograms.
59 to 65 inches or 150 to 167 centimeters.
Great Black-backed Gull landing on the rocks
The Great Black-backed Gull produces similar calls to other large gulls but has a lower-pitched voice. They make a variety of sounds, including gruff, deep-voiced growls in flight, and a trumpeting ‘long call’ is made while raising and lowering their head.
Great Black-backed Gull calling
Great Black-backed Gulls have a varied diet that includes fish, crabs, mussels, and other marine organisms. They also eat small mammals, other birds and their eggs, carrion, and scraps. They find their food in the intertidal zone, at the surface of open water, and around seabird colonies.
Great Black-backed Gull chicks eat fish and squid that both parents bring back to the nest. Younger chicks are fed directly from their parent’s bill, while older chicks eat meals regurgitated onto the floor.
Great Black-backed Gull out at sea with a fish in its beak
Great Black-backed Gulls are usually found in coastal habitats like rocky shores, sandy beaches, and estuaries, although they also forage further out to sea. They live around larger inland water bodies in some areas and may scavenge on dry fields or around rubbish dumps for scraps.
Great Black-backed Gulls are restricted to the northern Atlantic Ocean, from the East coast of North America to Greenland, and from Svalbard south to Portugal. They may range far inland, particularly around the Great Lakes of the United States and Canada.
Most Great Black-backed Gulls live near the seashore, although some birds travel inland and others forage further out to sea. They are accomplished swimmers, strong in flight, and comfortable on land.
Great Black-backed Gulls are generally rarer and more solitary than other large gulls. Their numbers vary depending on the season and quality of habitat.
Great Black-backed Gulls occur in coastal and continental shelf waters from Maine to Florida and rarely along the Gulf Coast to Texas. Look out for them throughout the year in the northeast but only in the winter south of North Carolina. They also visit the Great Lakes, traveling as far west as Lake Superior in winter.
Great Black-backed Gulls occur around the entire coastline of the United Kingdom. They also forage inland around dumps and reservoirs in the winter non-breeding season.
Great Black-backed Gulls occur along the eastern Canadian coastline from New Brunswick to Baffin Island. They also visit the Great Lakes in the winter, and some birds even breed around Lake Ontario and Lake Huron.
Great Black-backed Gull resting on the lake
Great Black-backed Gulls are known to live up to 26 years.
Adult Great Black-backed Gulls are formidable birds, and healthy adults have few potential predators other than large raptors like Bald Eagles and White-tailed Eagles. Their eggs and chicks are more vulnerable to other large Gulls, Ravens, Crows, Rats, and Raccoons.
Great Black-backed Gulls are a protected species in the United Kingdom, the United States, and Canada.
Great Black-backed Gulls are not endangered. These powerful seabirds have a large distribution and are ranked as a ‘Least Concern’ species on the IUCN Red List.
Pair of Great Black-backed Gulls resting on the rocks next to the sea
Great Black-backed Gulls nest on the ground in a shallow scrape lined with feathers, plant matter, trash, and other soft materials. They nest on rocky areas, sand dunes, salt marshes, and grassy ridges near the coast but always above the high water line.
Great Black-backed Gulls nest in the spring and summer. Most pairs lay their eggs in April or May. Their eggs take 26 to 28 days to hatch, and the young birds begin to fly when they are about 45 days old. Juveniles rely on their parents for over two months before gaining independence.
Great Black-backed Gulls lay blotched and speckled eggs with a buff or olive background color. Their eggs are large, measuring approximately 54 millimeters wide and 77 millimeters long.
Great Black-backed Gulls form long-lasting partnerships. They often mate for life, but pairs may divorce after unsuccessful nesting attempts.
Great Black-backed Gull sitting on its nest in rocky terrain
Nest of a Great Black-backed Gull with three eggs
Great Black-backed Gulls are highly aggressive, relying on their size and power to overcome large prey. They are also aggressive towards other gulls and their own species, particularly when raising their chicks. These birds fight by pecking and striking with their wings, sometimes injuring their opponent in the process.
Great Black-backed Gulls sleep on the ground in open areas such as beaches and fields, sometimes in large groups. They may lie on their belly or stand on one leg while sleeping, either resting their head against their breast or tucking it under their wing.
Great Black-backed Gull resting in open area by the coast
Great Black-backed Gulls are partial migrants. Some populations travel hundreds of miles to the south or inland after breeding, while others remain near their nesting grounds throughout the year.
Length:
64cm to 78cm
Wingspan:
150cm to 167cm
Weight:
1.3g to 2g
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