Is a Seagull a Real Species? Gull Types Explained

What is a seagull, then?

Gulls are seabirds in the subfamily Larinae, part of the family Laridae, which also includes terns and skimmers. Their closest relatives beyond that family are the skuas and the auks, such as the Atlantic puffin, and more distantly the wading birds.

Most gulls share a familiar design: a heavy body, long wings, webbed feet, a strong, slightly hooked bill and plumage in white, gray and black. They are excellent all-rounders that can fly, swim and walk well, and they are among the least specialized of all seabirds. That flexibility is why so many gulls have done well around people.

When a person in Britain or northwest Europe says “seagull”, they usually mean the large gray-backed herring gull. In the American Midwest it is more likely to be a ring-billed gull, in Florida a laughing gull, and in Australia the silver gull. The same word covers very different birds.

How many kinds of gull are there?

Checklists recognize roughly 50 to 55 gull species, and the number keeps shifting as DNA studies split some birds into separate species or lump others together. Gulls also hybridize quite often, which makes classification harder.

They range enormously in size:

Common gulls in Europe and North America

Herring gull. The classic gray-backed, pink-legged gull of European coasts and seaside towns, with a yellow bill marked by a red spot. Its American relative, the American herring gull, is now treated by many authorities as a separate species.

Great black-backed gull. The largest gull, with a black back and wings and a massive bill. It lives on both sides of the North Atlantic and is a powerful predator of other seabirds.

Ring-billed gull. A medium-sized North American gull with a black ring around its yellow bill and yellow legs. It nests mostly inland, around the Great Lakes and the northern prairies, and is the gull most people meet in parking lots and parks.

Laughing gull. A smaller gull of the Atlantic and Gulf coasts of the United States, the Caribbean and northern South America. In summer adults have a black hood and a dark red bill, and the call sounds like loud laughter.

Black-headed gull. A small, buoyant gull common on lakes, rivers and city parks across Europe. Despite its name, its summer hood is chocolate brown, and in winter only a dark spot behind the eye remains.

Not all gulls live by the sea

The “sea” in seagull is often misleading. The black-headed gull, the little gull and Franklin’s gull nest mostly on freshwater marshes and lakes. The California gull breeds on lakes in the dry interior of western North America, including the Great Salt Lake, and is the state bird of Utah (see the US state birds).

The most extreme example is the gray gull of South America, which nests in the Atacama Desert of northern Chile, one of the driest places on Earth, and flies to the Pacific coast to feed. At the other end of the scale, the black-legged kittiwake spends most of the year far out on the open ocean, more like a true seabird than most gulls.

Many gulls have also moved into towns. They feed at landfill sites and in streets, and some nest on rooftops. That boldness explains behavior such as why seagulls steal food.

Why gulls are hard to identify

Gulls change their plumage as they grow older. Small gulls such as the black-headed gull reach adult plumage in about two years, medium-sized gulls in about three, and large gulls such as the herring gull in about four. In between, young birds go through a series of mottled brown, gray and white stages. Bird watchers call them “two-year”, “three-year” and “four-year” gulls.

Adults change too. Many hooded gulls lose the dark hood in winter, and white-headed gulls get gray-brown streaks on the head. Leg and bill color, the shade of gray on the back and the pattern of black and white on the wingtips are key clues. Add frequent hybrids, and gull identification becomes a favorite challenge for keen bird watchers.

Myths and facts about seagulls

Myth: Seagull is a species. Fact: it is a general nickname covering about 50 species of gull.

Myth: Gulls only live at the seaside. Fact: many gulls breed inland on lakes, marshes, prairies and even deserts, and many urban gulls live far from the coast.

Myth: Gulls cannot drink seawater. Fact: gulls have salt glands above the eyes that remove extra salt, so they can drink seawater, although they prefer fresh water. See Can seagulls drink salt water?