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.
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.
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.
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.
Herring Gulls are known to be capable of seeing ultraviolet light.
Parasites of Herring gulls include the fluke Microphallus piriformes.