Common Gull

Adult common gulls are 40–46 cm (16–18 in) long and a wingspan of 100–115 cm (39–45 in), noticeably smaller than the herring gull and slightly smaller than the ring-billed gull. It is further distinguished from the ring-billed gull by its shorter, more tapered bill, which is a more greenish shade of yellow and is unmarked during the breeding season. The body is grey above and white below. The legs are yellow in breeding season, becoming duller in the winter. In winter, the head is streaked grey and the bill often has a poorly defined blackish band near the tip, which is sometimes sufficiently obvious to cause confusion with ring-billed gull. They have black wingtips with large white "mirrors" on the outer primaries p9 and p10, which are smaller than those in the short-billed gull. Young birds have scaly black-brown upperparts and a neat wing pattern, and pink legs which become greyish in the second year before tuning yellow. By the first winter, the head and belly are white, with fine streaks and greyish feathers grow on the saddle. They take three years (up to four in the Kamchatka subspecies) to reach maturity. The call is a high-pitched "laughing" cry.

The common gull breeds in the northern Palearctic from Iceland eastwards to northeast Siberia. It is mainly migratory and winters in Europe, the Mediterranean, Black and Caspian seas, Persian Gulf; Sea of Okhotsk, Japan, Korean Peninsula to southeast China. It occurs as a scarce winter visitor to coastal eastern Canada and as a vagrant to the northeastern US. The Kamchatka gull is occasionally seen in northwestern North America mainly in spring, and there is one autumn record in Newfoundland.

Like most gulls, they are omnivores and will scavenge as well as hunt small prey. The global population is estimated to be about one million pairs; they are most numerous in Europe, with over half (possibly as much as 80–90%) of the world population. By contrast, the short-billed gull population in Alaska is only about 10,000 pairs.