Gulls are scavenger birds belonging to the Larinae family, and are commonly referred to as seagulls or seabirds. Several different birds belong to this group, and though they may different somewhat in size and color, they do share some common characteristics. Though they live in coastal regions, contrary to popular belief, these birds do not usually fly far out to sea. For reasons of safety and food supply, the birds usually stay close to shore. Coloring can vary, but most gulls are white with black markings on their backs and wingtips.
The herring gull of the northern hemisphere is probably the most common species of Larinae. In some coastal areas, these birds are so plentiful that they are considered pests. They tend to follow fishing boats in an attempt to eat any bait that is cast. In open waters, these birds eat fish that are near the surface of the water, and on land, because they are carrion eaters, they typically eat dead fish that are washed to shore. In well-populated areas, seagulls are also often found scavenging in or around garbage dumps.
Gulls usually have one mate for life, but they travel and roost in flocks. In less populated areas, they often nest on the ground, close to the shoreline. In habitats where they feel more threatened, the birds usually roost in trees or on rooftops. When it is time for hatching, female gulls build nests out of seaweed and twigs. Though baby gulls begin flying within days after hatching, they stay under the mother’s care until they are about a month old.
Seagulls usually have a life span of about ten years, though in rare cases, they may live as long as 25 years. Life span usually depends on the food supply and the safety of their environment. Gulls that live in areas that are more isolated tend to live longer than those living near well-populated coastal environments.
Unlike most other birds, seagulls can safely consume salt water. This is because they have glands that are able to separate salt from the water, preventing it from entering their digestive tracts. These glands are located above and behind their eyes. Once salt is deposited into the glands, it is flushed out through their beaks.
Though most adult gulls are white, as babies they begin life with brown coloring. The birth coloring beings to gradually change as they grow older. Weight and wingspan of gulls can vary somewhat, depending on the type of gull. The average wingspan of seagulls range from about 40 inches (101 cm) to 60 inches (152 cm).