The American herring gull or Smithsonian gull (Larus smithsonianus or Larus argentatus smithsonianus) is a large gull that breeds in North America, where it is treated by the American Ornithological Society as a subspecies of herring gull (L. argentatus).
Adults are white with gray back and wings, black wingtips with white spots, and pink legs. Immature birds are gray-brown and are darker and more uniform than European herring gulls, with a darker tail. As is common with other gulls, they are colloquially referred to simply as seagulls.
It occurs in a variety of habitats including coasts, lakes, rivers, parking lots and garbage dumps. Its broad diet includes invertebrates, fish, and many other items. It usually nests near water, laying around three eggs in a scrape on the ground.
Taxonomy
This gull was first described as a new species in 1862 by Elliott Coues based on a series of specimens from the Smithsonian Institution. It was later reclassified as a subspecies of the herring gull (Larus argentatus). The genus name is from Latin Larus, which refers to a gull or other large seabird. The species name smithsonianus commemorates English chemist James Smithson whose £100,000 bequest enabled the foundation of the institution that bears his name.
The taxonomy of the herring gull group is very complicated and much is still controversial and uncertain. A 2002 study suggested that the American herring gull is not closely related to European herring gulls, belonging instead to a separate clade of gulls. Several authorities such as the Association of European Rarities Committees and British Ornithologists' Union now recognize it as a separate species. The BOU also includes the Vega gull (Larus vegae) of northeastern Asia within the American herring gull. The American Ornithologists' Union has not adopted the split and continues to treat the American herring gull as a subspecies of Larus argentatus.
Description
It is a heavily built large gull with a long powerful bill, full chest and sloping forehead. Males are long and weigh . Females are long and weigh . The wingspan is . Among standard measurements, the wing chord is , the bill is and the tarsus is .
Breeding adults have a white head, rump, tail, and underparts and a pale gray back and upperwings. The wingtips are black with white spots known as "mirrors" and the trailing edge of the wing is white. The underwing is grayish with dark tips to the outer primary feathers. The legs and feet are normally pink but can have a bluish tinge, or occasionally be yellow. The bill is yellow with a red spot on the lower mandible. The eye is bright, pale to medium yellow, with a bare yellow or orange ring around it. In winter, the head and neck are streaked with brown.
Young birds take four years to reach fully adult plumage. During this time they go through several plumage stages and can be very variable in appearance. First-winter birds are gray-brown with a dark tail, a brown rump with dark bars, dark outer primaries and pale inner primaries, dark eyes, and a dark bill, which usually develops a paler base through the winter. The head is often paler than the body. Second-winter birds typically have pale eyes, pale bill with black tip, pale head, and begin to show gray feathers on the back. Third-winter birds are closer to adults but still have some black on the bill and brown on the body and wings and have a black band on the tail.
Voice
It has no song but possesses a variety of cries and calls. An initial call in response to a threat is a quick "hahaha", varying in intensity depending on the threat. The more-intense "keow" is a loud yet short alarm call that is both identifying and communicative of impending danger. The "long call" is a series of loud notes during which the head is dipped and then raised. The "choking" call is produced during courtship displays, nest construction or territorial disputes, accompanied by a rapid bobbing of the head in a direction of interest. The "mew" call is used with an extended downturned neck to call attention in many contexts including chick or mate calling and nest defense. Juvenile birds emit high-pitched plaintive cries to elicit feeding behavior from a parent and may also emit a clicking distress call when a parent suddenly flies off .