Ring-billed Gull

Larus delawarensis

(c) Ashok Khosla
  • LARIDAE
  • Gulls, Terns, and Skimmers
  • Charadriiformes
  • Apipizca pinta
  • Goéland à bec cerclé
Introduction
Loafing at parks, swarming over lakes, and roosting atop floodlights, Ring-billed Gulls are a familiar sight to many Americans. Industrial farming practices, the proliferation of open garbage dumps, and the end of human persecution in the 1920s have allowed this "land gull" to thrive across most of North America over the last 40 years. Many bird watchers begin to learn the fine details of gull identification by observing the cosmopolitan and obliging Ring-billed Gull.
Lee Karney, US FWS
Appearance Description
On average, Ring-billed Gulls weigh a little over one pound and measure 17.5 inches long, with a 48-inch wingspan. This gull is medium-sized, but can appear small in large landscapes or next to other gull species. The adult Ring-billed Gull's body plumage is white, and its pale gray wings are tipped broadly with black. In winter, its head is streaked with gray. The legs and bill are yellow, and the bill has a complete, thick black ring just before the tip, for which the bird is named. The eyes are pale yellow. Ring-billed Gulls take two years to reach adult plumage. Immature stages are complex and variable; they warrant significant study for proper identification.
Range Map
Courtsey Kenn Kaufman
Range Distribution
The Ring-billed Gull's range has expanded exponentially since the 1960s, and at various times it may be found anywhere in North America south of the boreal forests. These gulls breed across the middle section of North America, from coast to coast, with concentrations in northern California, the Great Plains, the Great Lakes, and the St. Lawrence Seaway. The Ring-billed Gull's wintering range covers most of the United States, with the exception of the upper Great Plains, parts of the Rocky Mountains, and the desert southwest. In winter, they concentrate around human habitations, landfills, and coasts.
 
A legend for the range map to the right can be found here.
Habitat
The Ring-billed Gull lives on land near water and has adapted well to human alteration of its historic habitat. It breeds on sparsely vegetated islands and small peninsulas. Fresh water lakes, bays, large rivers, and reservoirs are preferred, but the coasts may be used as well. Western populations usually nest within 20 miles of a town with at least 1,000 people. At all times of the year, farmland is important for Ring-billed Gulls, but they also forage in parks, golf courses, malls, fast food restaurant lots, landfills, and waste treatment facilities.
Feeding
The Ring-billed Gull is omnivorous and eats whatever is available. With long strides, it searches for prey over beaches, lawns, fields, and garbage heaps. Stirring mud in the shallows, chasing insects on the wing, and diving or dipping into the water, this gull often forages in flocks. Its diet includes many fish (alewife, stickleback, and perch), insects (true bugs, beetles, cicadas, flies) grain, rodents, and earthworms.
Reproduction
In colonies numbering as many as 80,000 pairs, Ring-billed Gulls nest on the ground, usually near logs, low plants, or human refuse. Males establish small territories and attract mates with long calls and ritualized postures. The pair bonds are cemented when the female begs for food, which the male regurgitates and she eats. Nest may vary from barely a scrape to an arrangement of sticks, grasses, leaves, and mosses. For the duration of the season, the pair cooperates in all phases of breeding.
 
Some Ring-billed Gulls have an unusual breeding pattern. Up to 8% of breeding pairs, usually in large and expanding colonies, are comprised of two fertilized females that cooperate in rearing a combined brood. The two to three olive to gray eggs are incubated for 23 to 28 days. The gray, downy chicks are initially helpless, but can walk within two days and swim within three. The hatchlings' defenses include running away, crouching to hide, and attacking. They eat most adult foods, which are regurgitated onto the ground. Ring-billed Gulls fledge in 40 to 45 days, and the familial bonds dissolve.  
Migration
Comprised of individuals or loose flocks, migration is disorganized and follows a wide dispersal of Ring-billed Gulls after breeding in the fall. Migration is most noticeable in October and complete by December. Ice cover and food shortages regulate winter migration. Some Ring-billed Gulls use traditional staging areas like the eastern Great Lakes and routes like the passage from the Great Lakes to the east coast, then southward into Florida. Spring migration peaks in March and April, and is relatively brief.
  • 2,550,000
  • 2,550,000
Population Status Trends
The Ring-billed Gull's large populations have been growing rapidly since the 1960s. From 1967 to 1976, these increases averaged 7.9% each year, then rose to 11% per year between 1976 and 1984. Some regions, like those along the St. Lawrence River, experienced an annual population growth of over 20%. Since the mid-1990s, Christmas Bird Count data suggest a significant slowdown in this growth rate, with larger fluctuations in wintering populations.
Conservation Issues
Following decimation by feather hunters, egg hunters, and land grabbers, Ring-billed Gull populations recovered in only a few decades. This "land gull" has adapted to urbanized and industrialized landscapes, but its future depends on how Americans manage its abundance. For some landowners and water resource managers, Ring-billed Gulls have become undesirable, with large flocks picking through landfills and winter fields, and inhabiting lakes used for recreation and water supplies. The technique of scaring gulls from roosts and breeding colonies has had some success. The adaptable Ring-billed Gulls quickly find other food sources and roosting sites, like the roofs of industrial buildings in the Great Lakes region. In Ontario during the 1980's and 1990's, colony sites were bulldozed or covered with monofilament wire, sometimes in the effort to decrease predation by Ring-billed Gulls on Tern colonies. Results were mixed. The systematic destruction of Ring-billed Gull eggs does control population, but is required annually to remain effective. Better management of landfills, including partial incineration of waste and timely covering of new refuse, might help control gull populations.
 

Public involvement in this gull's conservation will require greater education and awareness. The Ring-billed Gull is one of few North American waterbirds that are both abundant and conspicuous. But the common perception of "sea gulls" swarming over rubbish piles robs the Ring-billed Gull of its identity as a species and ignores its special adaptations to living on land and sea.

What You Can Do
Embrace winter at a winter birding festival. Find Ring-billed Gulls among many other species at the annual Niagara River International Gull Festival in December, Niagara Falls, Ontario, Canada; or the annual Morro Bay Winter Bird Festival every January in California.
 
Support the robust regulation of North America's water and become familiar with the latest revisions of federal regulations, like the Clean Water Act. Share your ideas and concerns with your state and federal representatives, who can help enact legislation to keep our water cleaner.
 
For more actions you can take, including Audubon activities, please visit our resources page.
More Information
Visit our resources page for more information about this species.
Natural History References
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Ryder, J. P. 1993. Ring-billed Gull (Larus delawerensis). In The Birds of North America, No. 33 (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornithologists' Union.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
Conservation Status References
Belant J.L.; Ickes S.K.; Seamans T.W. "Importance of landfills to urban-nesting herring and ring-billed gulls." Landscape and Urban Planning 43:1 (28 December 1998) 11-19.
 
Dwyer, Chris, Jerrod L. Belant, and Richard A. Dolbeer. "Distribution and Nesting of Roof-Nesting Gulls in the Great Lakes Region of the United States." Ohio Journal of Science 96:1 (1996) 9-12.
 
Morris, R. D., H. Blokpoel, and G. D. Tessier. "Management efforts for the conservation of common tern Sterna hirundo colonies in the Great Lakes: Two case histories." Biological Conservation 60:1 1992() 7-14.
 
Ryder, J. P. 1993. Ring-billed Gull (Larus delawerensis). In The Birds of North America, No. 33 (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornithologists' Union.
 
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, Results and Analysis 1966 - 2005. Version 6.2.2006. USGS Patuxent Wildlife Research Center, Laurel, MD.
 

Sibley, David Allen. The Sibley Guide to Birds.New York. 2000. Alfred A. Knopf,