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The Ivory Bill·Birds·Seabirds

American Herring Gulls, Larus smithsonianus

Herring gulls standing on the wet beach.

American Herring Gulls are large seabirds that breed in a variety of coastal and inland habitats across North America, including islands, rocky shores, and lakes, from April to July.

American Herring Gulls are commonly found in coastal cliffs, islands, and occasionally urban areas, where fish, crustaceans, and other marine invertebrates are abundant during the breeding season.

They forage in diverse habitats, including open ocean, beaches, mudflats, and garbage dumps for fish, crabs, mollusks, sea urchins, and marine worms. They may also feed on carrion, eggs, and small mammals, and are known to scavenge in urban areas.

American Herring Gulls have robust foraging strategies, including plunging into water to catch fish, scavenging along shorelines, and even kleptoparasitism, where they steal food from other birds. Their powerful beaks allow them to handle a wide range of prey and food sources.

Courtship involves complex displays, including the “choking” display where the male arches his neck, points his bill downward, and makes rhythmic calls. The pair may also engage in mutual preening and “head-tossing” displays, where they throw their heads back and call.

Nest building is done by both parents, who construct a large, bulky nest from grass, seaweed, twigs, and other materials. Nests are usually located on the ground in sheltered locations or elevated sites on cliffs or buildings.

Egg laying occurs from late April to early June, with the female usually laying two to three eggs. Both parents share incubation duties, which last about 28 to 30 days. Upon hatching, the chicks are semi-precocial and require significant parental care. Initial diets for chicks consist of regurgitated fish and invertebrates provided by the parents.

Chicks learn to forage by following their parents and watching their foraging techniques. They face vulnerabilities such as predation by larger birds, mammals, and human disturbances. Parental care includes leading chicks to food sources, protecting them from predators, and teaching them how to handle different prey.

Chick fledging occurs about 45 to 50 days after hatching, with continued guidance from adults as the chicks develop their foraging skills. Their diet evolves to include a broader range of fish and invertebrates as they grow and learn to exploit various food sources.

American Herring Gulls undertake partial migratory journeys, with some populations moving southward to winter along the coasts of the United States, the Gulf of Mexico, and the Caribbean. Migration occurs from late August to October, following coastal and inland routes.

Wintering habitats include coastal bays, estuaries, and inland lakes, where they forage for fish, crustaceans, and marine invertebrates. Their diet during winter is diverse, adapting to the availability of food in different coastal and inland environments.

American Herring Gulls typically leave their wintering grounds in late February to early March, returning north to their breeding areas as temperatures rise and food becomes more abundant in preparation for the breeding season.