The herring gull, Larus arentatus, and ring-billed gull, Larus delawarensis, (Family: Laridae) are two of the more than 50 species of gulls throughout the United States. They are the two most commonly encountered gulls in the Northeast; their range extends from Maine south and along the Gulf Coast to New Orleans. Both species can be found the length of the Mississippi River basin. The herring gull also occurs throughout most of Canada; the ring-billed gull is in the middle Plain States.

Identification: Gulls are distinguished from other birds based on their large size, long pointed wings, square tails, hooked bills and webbed feet. The Herring gull is 23 to 26 inches (58 to 66 centimeters) long. It has a light gray back and wings, which have black tips with white spots. It has a white head and breast, a red spot near the tip of the lower portion of its bill and yellow eyes. The Ring-billed gull is 18 to 20 inches (46 to 51 centimeters) long. It has a slightly darker gray back and wings, which have black tips with white spots. It has a white head and breast, a black ring near the tip of its bill and yellow eyes. The Laughing gull is 15 to 17 inches (38 to 43 centimeters) long and is easily recognized by its black head. The greater black-backed gull is black on its back and the top of its wings; however, the wing tips are white, as are its head, breast and tail.

Biology : Both species tend to nest in colonies on the ground. The nest is constructed of seaweed, grass, sticks and feathers. Herring gulls occasionally nest on ledges or cliffs, whereas ring-billed gulls occasionally nest in low trees.

Habits : Gulls feed on a wide variety of materials, including fish, clams, mussels, garbage, dead animals, insects, earthworms, rodents and fledgling gulls. The ring-billed gull is the species most often found around fast food restaurants, whereas the herring gull prefers landfill areas. They often loaf in large open areas with a good field of view.

They are very gregarious birds, often roosting by the thousands during the breeding season and winter. It is not uncommon to find several species roosting together. Feeding sites can be located as far as 40 miles (64 kilometers) from the roosting area.

Damage : Gulls in the urban environment are often a major nuisance. They foul public areas and residential and commercial buildings with their extremely smelly droppings. The droppings carry numerous diseases and bacteria. They can be very noisy and aggressive when begging for food. Gulls are responsible for more than 50 percent of documented aircraft bird strikes. Furthermore, they are a particular nuisance around harbors, landfills and agricultural areas.

Ring-billed gulls have adapted their nesting habitat to rooftops of buildings in some locations. The feathers and litter the gulls bring into the nest site cause roof drains to clog and water overflows into the buildings below. They also peck holes in flat roofs covered with rubber type coatings. The resulting leaks cause damage to the buildings’ ceilings and contents.