The City Naturalist

City Naturalist

Ring Billed Gull

Article and Photos by Leslie Day

RING BILLED GULL (Larus delawarensis. Genus name-Larus Latin from Greek word meaning a ravenous seabird; species name - delawarensis: the specimen from which the species was named and described was collected along the Delaware River below Philadelphia.)
OTHER NAMES: Common gull; lake gull

DESCRIPTION: The ring billed bull is a very common seagull, the most common and numerous here at the Boat Basin. It strikingly resembles the larger herring gull, which it can be distinguished from by the black ring around the tip of its bill (from which it gets its common name) and by its yellowish or greenish legs. The ring billed gull is 18-20" high, with a wingspread of about 48". The adult is silvery gray on back and wings, white on head, tail and underparts, resembling, in some ways, a dove. The gull yellow feet and a narrow black ring around its bill. Young (immature) birds are mottled brown, paler than a young Herring gull, and have a blackish tail band and flesh-colored legs. The black wing tips have small white spots and look like long tail feathers. However, if you watch the birds take off, you will notice that the black is really their wingtips.

FEEDING HABITS: When inland, ring billed gulls live on small rodents, grasshoppers caught in flight, worms, grubs and other insects picked up in freshly plowed fields. They catch fish and scavenge garbage dumps and scavenge along beaches of large bodies of water. Ring billed gulls occasionally eat the eggs of cormorants and other associated nesting species. When catching fish they splash in from a low hover but never fully immerse themselves. They can seize insects on the wing. At low tide they walk in the tidal flats and eat crustaceans and mollusks. At the boat basin this past winter, people were literally feeding them from the palm of their hands.

VOICE: Loud raucous mewing cry, can be quite high pitched.

RANGE: Alaska and Labrador south to the Great Lakes and California. Winters along Atlantic seaboard, Pacific coast form Washington and in interior from Wyoming south to Mexico. However the population of Ring billed gulls here at the Boat Basin seems to be here summer and winter.

POPULATION: Once the most common gull of North America, by the turn of this century, ornithologists were concerned about greatly declining numbers, especially along the Northeastern coast. Today their numbers are rising again and they are breeding along the Atlantic seaboard. Among North American gulls, only the herring gull outnumbers them.

NESTING: Usually in colonies on islands or shores of freshwater lakes associated with terns, cormorants, ducks and other gulls; nest about 12 inches across, is made of weeds, grasses, and debris stacked on bare or rocky ground; rarely in low trees. As far as we know, none of the bird watchers at the 79th Street boat basin have ever seen a Ring billed gull nest. Perhaps they are nesting across the river in New Jersey.

BEHAVIOR: We have noticed interesting social behavior in the Ring billed gull. If one gull snatches up a fish or crab from the river, another gull will often follow it making soft begging sounds. Once on the land, or dock, that bird will circle the gull with the food and bob its head and body up and down, softly crying and begging for some food. When we feed these gulls form our boat, we throw bread in the air and they can catch it on the wing. They are intelligent, watchful, highly social animals.

EGGS: May-June, usually 3, light brown, marked with darker browns, lavender, and gray. Incubation about 21 days; young swim at early age when taking to water to escape enemies; age at first flight unknown; most require 3 years to attain adult plumage.

AGE: Oldest wild gull found dead was at least 21 years old. However in one study average age was 3-5 years.

FLIGHT SPEED: ll-43 miles per hour.

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