Gulls are from the order Chaeadriiformes and the family Laridae, as are terns. Gulls, unlike terns, comprise the subfamily Larinae.
All gulls are sturdy looking with long pointed wings and an almost square tail. Their feet are webbed and their bills are hooked. When landing in the water to grab food, they alight almost gently rather than dive.
Generally their flight is strong with deliberate wing-beats but some gulls also soar. Opportunists, gulls are mostly scavengers and are at home around human gatherings where they can expect to seize the garbage and refuse left behind by people.
Most adult gulls are some combination of white, grey and black. The markings of gulls are the same in the female and male. Immature gulls have different markings and some gulls may not have their adult plumage for several years. Gulls nest in colonies and generally produce 2 to 5 eggs each year.
The Herring Gull, Larus argentatus, is the most common species found in the United States. Early European colonists on our shores found the herring and great black backed gulls so common and people friendly that they could be easily killed for food.