Breeding adults have a black head, black legs and feet, and a red bill. The neck, underside of the wings, belly, and tail are white. The upper side of the wings is dark gray, and the outer flight feathers are black. 42 cm (16.5 in) in length; 102 cm (40 in) wingspan. During the winter, the adult's head changes to white, and the bill becomes black. The juvenile Laughing Gull is mottled brown, with a white belly, and a black bill, outer flight feathers, legs, feet, and tail. In the first winter, its back is dark gray, and the head and neck begin to change to white. During the second winter, the plumage is dusky white on the head and neck, and the tail is almost all white. Breeding plumage indicates a bird that is at least two years old.
The breeding season begins in early April and extends into July. Laughing Gulls nest in colonies, which can be very large. The nest is common in coastal areas on the ground or within the beach grasses. The female lays 2-4 (usually 3) eggs that both adults incubate for 21-23 days. The young are semi-precocial and leave the nest within a few days of hatching. The adults tend to the young for approximately 35 days after hatching.
The diet of this gull includes aquatic invertebrates, garbage, insects, and occasionally fish. As is true with most gull species, the Laughing Gull, will steal food from another bird if the opportunity occurs. Sometimes it also takes other sea bird eggs or chicks to eat. The food is gathered by picking it from the beach or water, or by diving from above to capture fish or force another bird to drop its food.
The Laughing Gull occurs in the eastern coastal United States. In northeastern coastal areas, it occurs only during the summer, but in the South and Southeast it occurs throughout the year.
This species is common and not listed as Threatened or Endangered in any part of the Southeast.
The Laughing Gull is the most similar to the Franklin's Gull. The Franklin's Gull is smaller and has less dark coloration on the underside of the flight feathers. The Franklin's Gull is rarely found along the coastal areas.