Herring Gull. Description

The herring gull (Larus argentatus), is a large seabird of the family Laridae (gulls). As adults herring gulls have a white head and body, pale gray back and wings, and black wingtips. Juvenile herring gulls change from a completely grayish brown first-year plumage through a series of plumages before achieving the adult plumage at four years of age.

Herring gulls inhabit shorelines and coastal waters of large bodies of water, including oceans, seas, lakes, and large rivers. Their breeding range is circumboreal (throughout the temperate to cool areas of the Northern Hemisphere), including much of Central Asia. It may be the most common and familiar gull of northeastern North America and Western Europe.

In North America, it breeds along the Atlantic Coast from Cape Hatteras, North Carolina, north to Baffin Island in northern Canada and Davis Strait between Baffin Island and Greenland, and throughout Arctic Canada into Alaska. In winter, herring gulls may be found throughout their breeding range and south into tropical waters, primarily along coastlines in California and the Gulf of Mexico.

This species has been divided into at least nine subspecies, of which only one, L. a. smithsonianus, breeds in North America. Several Asiatic and European subspecies have recently been accorded tentative species status. Herring gulls form hybrids in zones of sympatry (overlapping ranges) with several other large white-headed gulls, including the glaucous-winged gull and the lesser black-backed gull, and the possibility exists that new species have arisen through hybridization in this group in Asia.

The behavior and ecology of this species are very well studied, especially in Europe, Canada, and New England. Herring gulls form male-female pairs that can last for the lifetime of the individuals, which can exceed twenty years. Male gulls establish breeding territories that they share with their mates and upon which they raise their offspring.

Their primary nesting habitat requirement appears to be a site that is near a body of water and safe from terrestrial predation; examples include islands, offshore rocks, abandoned piers, and so forth. Gulls have a wide variety of vocalizations that function to warn other herring gulls of dangers and as communication between neighbors, members of a pair, and parents and offspring. The herring gull typically lays three eggs in May; the offspring achieve independence by mid to late July, although parents may care for them for up to six months after fledging.

Herring gulls are opportunistic feeders that take a wide range of food types, including fish, marine invertebrates, small mammals, seabirds and eggs, and human refuse. Most birds feed primarily on natural prey, and successful breeding is related to taking of natural prey in most areas. Studies from both Europe and North America indicate that gulls show individual foraging specialization, and that diet choice influences breeding performance. Birds that feed primarily on human refuse have low breeding success, primarily because eggs do not hatch.

Herring gulls were driven to near extinction by plumage hunters and eggers in North America during the nineteenth century. Populations have recovered as a result of protection under the Migratory Bird Act. By the 1960s population sizes may have exceeded historical numbers, possibly because of feeding on fisheries waste and increased overwinter survival from feeding on human refuse. Numbers in New England stabilized during the 1970s.

In recent years the species has expanded its range south into Maryland, Virginia and North Carolina, but herring gulls have also been largely displaced from some breeding habitats in New England by great black-backed gulls (L. marinus).