Photo: Don Faulkner/Flickr Creative Commons

Great Black-backed Gull

Larus marinus

Our largest gull. Primarily a bird of the Atlantic Coast, seldom seen inland except around the Great Lakes. Because of its large size and omnivorous feeding habits, the Great Black-back can be a significant predator on other species of birds during the nesting season. It has benefitted from certain human activities (such as the establishment of garbage dumps) and has expanded its range southward along the Atlantic seaboard in recent decades.
Conservation status Has been increasing its population in North America at least since the 1930s, with the breeding range steadily expanding southward along the Atlantic Coast and inland to some areas of the Great Lakes.
Family Gulls and Terns
Habitat Mainly coastal waters, estuaries; a few on large lakes. Close to coast at most seasons, but will forage far offshore in winter over the continental shelf. Some regularly move inland along St. Lawrence River to Great Lakes, rarely other fresh waters. Nests mostly on islands, tops of sea cliffs, sometimes on mainland beaches and marsh edges.
Our largest gull. Primarily a bird of the Atlantic Coast, seldom seen inland except around the Great Lakes. Because of its large size and omnivorous feeding habits, the Great Black-back can be a significant predator on other species of birds during the nesting season. It has benefitted from certain human activities (such as the establishment of garbage dumps) and has expanded its range southward along the Atlantic seaboard in recent decades.
Photo Gallery
  • adult, breeding
  • immature (1st year)
  • immature (2nd year)
  • immature (3rd year)
  • adult, nonbreeding
  • immature (1st year)
  • immature (2nd year)
Feeding Behavior

Opportunistic. Forages on foot, while flying, or while swimming. May steal food from other birds. May break open hard-shelled mollusks and eggs by flying high and dropping them on rocks. Often scavenges on refuse around fishing boats, docks, garbage dumps.


Eggs

2-3, sometimes 1-5. Olive to buff with brown blotches. Incubation is by both sexes, 27-28 days. Young: Both parents care for and feed young. Downy young may wander from nest after a few days, but remain in general area. Young are capable of flight at 7-8 weeks after hatching, become independent soon thereafter.


Young

Both parents care for and feed young. Downy young may wander from nest after a few days, but remain in general area. Young are capable of flight at 7-8 weeks after hatching, become independent soon thereafter.

Diet

Omnivorous. Diet includes carrion, fish, mollusks, crustaceans, marine worms, insects, rodents, berries, and the adults, young, and eggs of other birds.


Nesting

Usually first breeds at age of 4-5 years. Generally nests in colonies, often mixed with Herring Gulls or other birds; sometimes nests in isolated pairs. Nest site is on ground, often on top of or beside a rocky outcropping. Nest (built by both sexes) is mound of grass, seaweed, moss, debris, with shallow depression in center.

Illustration © David Allen Sibley.
Learn more about these drawings.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

Present all year in most parts of breeding range, but withdraws in winter from coast of Labrador, and a few move south as far as Florida. Numbers in southeast and on Great Lakes increase in winter. Very rare on Gulf Coast and in most inland areas.

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Migration

Present all year in most parts of breeding range, but withdraws in winter from coast of Labrador, and a few move south as far as Florida. Numbers in southeast and on Great Lakes increase in winter. Very rare on Gulf Coast and in most inland areas.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Similar to that of Herring Gull, but deeper and more guttural, a deep keeow.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How climate change could affect this bird's range

In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.

Learn more

Read more: climate.audubon.org
Gulls and Terns Gull-like Birds

Great Black-backed Gull

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season.

More on reading these maps.

Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”

The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).

The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.

The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.

The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.

You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.

The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
Winter
Summer

Winter Range
Summer Range
Both Seasons
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