Laughing gulls are omnivorous and will scavenge as well as hunt suitable small prey. Being highly vocal, their name comes from their call, which sounds like a series of laughing notes.
Laughing gulls have a white body and dark grey back and wings and a black head. Its wings are much darker than other gulls its size, and they have a long, red bill. In the wintertime, the black head mostly disappears.
This gull takes three years to reach adult plumage. Immature birds are darker and first-year birds are greyer below and have paler heads.
Laughing gulls breed in coastal marshes and ponds in large colonies. The large nest, made mostly of grass, is built on the ground. The male and female gull usually build their nest together. If a male cannot find a mate, he may start building a nest platform and then use it to attract a female. The female gull lays three to four greenish eggs, which are incubated for about three weeks.
The adult laughing gull removes the eggshells from the nest after the eggs hatch. If the shells are not removed, a piece can become lodged on top of the slightly smaller unhatched third egg and prevent it from hatching.