Courtesy Kenn Kaufman
Herring Gulls occur over much of the Northern Hemisphere between the tropics and the Arctic Circle. In North America, the Herring Gull breeds from the Aleutian Islands southeastward through the Great Lakes and along the Atlantic Coast from the Carolinas to Newfoundland. Since the 1950s, its breeding range has expanded southward from Maine, once its southern limit. In winter, these large, white-headed gulls concentrate in the Great Lakes region and along the Atlantic, Gulf, and California coasts. During migration, Herring Gulls can be anywhere in North America.
A legend for the range map to the right can be found here
Herring Gulls are always on or very near large bodies of open fresh or salt water, including bays, estuaries, lakes, large ponds or impoundments, reservoirs, and rivers. Nests are built on islands made of rock, sand, or dredged material. These large gulls look for food near shore at sea, along mud and sand flats, rocky shores, landfills, fish and other food processing plants, farm fields, and parks.
The omnivorous Herring Gull eats mussels, squid, fish, crabs, other birds and their chicks and eggs, earthworms, insects, and human refuse. It swallows food whole when possible, but can peck open thin shells or drop thicker ones onto hard surfaces. Herring Gulls forage on water or land, and can dive short distances after prey. Fishing boats and fish docks provide important feeding areas. An intelligent and persistent predator, this gull can scavenge, use whales to find fish or squid, or steal food from other birds. One scientist observed a Herring Gull using bread to attract goldfish.
Starting in early spring, Herring Gulls form monogamous pairs for the duration of the breeding season. A variety of displays, including begging and head tossing, serve to bond pairs. In a colony, often with other gull species, the male establishes a territory with vocalizations and physical displays like ritualized grass pulling and charging. Herring Gull pairs cooperate in all phases of breeding; they choose a nest site 12 to 30 feet from other nests, press a hollow into the ground, and fill it with vegetation, feathers, and flotsam. Prior to egg laying, the male supplements the female’s diet with regurgitated food. The female usually lays three olive to green eggs with brown and black markings, which are incubated for about 30 days.
The black-spotted gray chicks can walk within a day. Young chicks peck at the red spot on the adults’ beak to stimulate regurgitation of fish, crustaceans, squid, and insects. When the last-hatched chick is not fed enough, it sometimes leaves the territory. Neighboring gulls may either kill or adopt it. Herring Gulls fledge in about seven weeks and are usually fed for a total of 12 weeks. Juveniles sometimes stay with a parent throughout the winter, but most young Herring Gulls form loose flocks and move south in the fall.
When breeding ends, both adults and young leave their immediate nesting sites, but adult Herring Gulls stay in the general area year round, providing open water and food are available. Herring Gulls in the Canadian Atlantic Provinces shift southward into New England, and large flocks comprised of all age groups are found offshore in winter. Young gulls migrate short distances to the Atlantic and Gulf coasts.