Bird Fact Friday — the Great Black-Backed Gull

Adapted from page 155 & 158 of Gulls Simplified:

This very large, menacing-looking gull (it truly is the largest gull in the world) has a big, squarish or oval-shaped head and a heavy bill. This barrel-chested gull is typically noticeably larger and always chestier than Herring Gull, with a larger, broader head, thicker neck, and distinctly heavier bill. Dull pink legs are long, thick, and set at midspan, accentuating the bird’s barrel-chested appearance.

Adults have a dark charcoal to black back and a white head, while immature birds are spangled or granite patterned with gray, white, and black upperparts and a white head. This contrasting pattern stands out among the brownish-gray immatures and gray-backed adult ranks of Herring Gulls.

Great Black-backed is a fairly sedentary gull, spending much of its time loafing on the beach, resting on the water, or standing atop an elevated post or light fixture. It walks somewhat reluctantly, with a waddling sailor’s gait. This species generally dominates other gulls when food is available and frequently displaces other gulls from prime perches. It is often found with other large, white-headed Gulls, especially Herring Gulls. Much smaller Ring-billed Gulls go out of their way to avoid any interaction with this species.

Great Black-backed Gull is typically the largest and huskiest gull on the Atlantic
beachfront or Great Lakes shorelines, or anywhere else it is found, since it is the largest gull in the world. Photo credit: Kevin Carlson

A consummate kleptoparasite (stealer of another’s food), Great Black-backed often robs cormorants, other gulls, and seabirds of fish and other food items. This species is also highly predatory. It is known to harass diving birds, such as coots (which can’t stay underwater very long), to exhaustion and then grasp the debilitated bird by the head, killing it outright or, failing that, drowning its victim. Kevin [Karlson, co-author of Gulls Simplified] once saw an adult Great Black-backed kill and swallow whole a Northern Flicker that had been sitting exhausted on a beach in New York during fall migration.

This is a fairly common gull that is typically found on Atlantic coast beaches, where it is a resident species, as well as on the Great Lakes, where it is also resident and increasing in numbers. Lesser numbers are found south to Florida (mostly on the Atlantic coast), where it is also increasing.

Gulls Simplified
A Comparative Approach to Identification
By Pete Dunne and Kevin Karlson

This unique photographic field guide to North America’s gulls provides a comparative approach to identification that concentrates on the size, structure, and basic plumage features of gulls—gone are the often-confusing array of plumage details found in traditional guides.

Featuring hundreds of color photos throughout, Gulls Simplified illustrates the variations of gull plumages for a variety of ages, giving readers strong visual reference points for each species. Extensive captions accompany the photos, which include comparative photo arrays, digitized photo arrays for each age group, and numerous images of each species—a wealth of visual information at your fingertips. This one-of-a-kind guide includes detailed species accounts and a distribution map for each gull.

An essential field companion for North American birders, Gulls Simplified reduces the confusion commonly associated with gull identification, offering a more user-friendly way of observing these marvelous birds.

  • Provides a simpler approach to gull identification
  • Features a wealth of color photos for easy comparison among species
  • Includes detailed captions that explain identification criteria and aging, with direct visual reinforcement above the captions
  • Combines plumage details with a focus on size, body shape, and structural features for easy identification in the field
  • Highlights important field marks and physical features for each gull


This post is part of a series, explore additional posts here<< Bird Fact Friday — Hybrid GullsBird Fact Friday — Western Gulls >>