The Herring Gull, Larus argentatus, is a large gull which breeds across North America, Europe and Asia. Some herring gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, e.g. those on the lower Great Lakes, on the east coast of North America or at the North Sea shores. Herring Gulls are also abundant around inland garbage dumps, and some have even adapted to life in inland cities.

Herring Gull flocks have a loose pecking order, based on size, aggressiveness and physical strength. Communication between these birds is complex and highly-developed - employing both calls and body language. Two identical vocalizations can have very different (sometimes opposite) meanings, for example - depending on the positionings of the head, body, wings and tail relative to each other and the ground in the calling gull.

Unlike many flocking birds, Herring Gulls do not engage in social grooming and keep physical contact between individuals to a minimum. Outside of the male/female and parent/chick relationship, each Herring Gull attempts to maintain a respectful 'safe distance' from others of its kind. Any breach of this results in fighting, though severe injuries are seldom inflicted.

The taxonomy of the Herring Gull / Lesser Black-backed Gull complex is very complicated, different authorities recognising between two and eight species.

This group has a ring distribution around the northern hemisphere. Differences between adjacent forms in this ring are fairly small, but by the time the circuit is completed, the end members, Herring Gull and Lesser Black-backed Gull, are clearly different species.

Adult Herring Gulls are similar to Ring-billed Gulls but are much larger, have pinkish legs, and a much thicker yellow bill with more pronounced gonys. First-winter Herring Gulls are much browner, but second and third-winter birds can be confusing since soft part colors are variable and third-year Herring Gull often show a ring around the bill. Such birds are most easily distinguished by the larger size and larger bill of Herring Gull.

The Association of European Rarities Committees recognises six species:

Herring Gull, Larus argentatus

American Herring Gull, Larus smithsonianus

Caspian Gull, Larus cachinnans

Yellow-legged Gull, Larus michahellis

East Siberian Gull, Larus vegae

Armenian Gull, Larus armenicus

Adults are easily identified by their size, pale grey back and the red spot on the beak. Legs are pink at all ages. The bird depicted is the western European race Larus argentatus argenteus. The Scandinavian race L. a. argentatus is slightly larger and darker, with more white in the wing tips.

The North American American Herring Gull is similar to argentatus, except that immature birds tend to be darker and more uniformly brown.

These are omnivores like most Larus gulls, and will scavenge on rubbish tips and elsewhere, as well as seeking suitable small prey in fields or on the coast, or robbing plovers or lapwings of their catches.

Eggs, usually three, are laid on the ground or cliff ledges in colonies, and are defended vigorously by this large gull. The loud laughing call is well-known in the northern hemisphere.

Herring Gulls are known to be capable of seeing ultraviolet light.

Parasites of Herring gulls include the fluke Microphallus piriformes.