Short-billed Gulls frequent lakes, rivers, and shorelines for most of their lives, in freshwater, brackish, and saltwater environments. During the breeding season, they nest in most of the habitats associated with the far north: taiga (boreal forest), tundra, marshes, meadows, coastal cliffs, and islands in rivers and lakes. After breeding, adults and young gather along streams, lakeshores, and mudflats, moving toward Pacific Ocean shores as they begin migration southward. Wintering birds tend to stay near the Pacific Coast, feeding in inshore marine waters, lagoons, estuaries, mudflats, bays, and harbors near the coast. Like their larger relative the Ring-billed Gull, Short-billed Gulls also forage in wet fields, pastures, landfills, sewage treatment facilities, and even behind active farming equipment—wherever they find prey. They rest on mudflats, rock jetties, and beaches, often among other gulls.Back to top
Like other gulls, Short-billed Gulls are opportunistic omnivores and employ many different foraging strategies in a single day, depending on what foods are available. Over most of the year, they prey on marine organisms, especially small fish, crabs, and bivalves such as mussels; also tiny crustaceans (euphausiids, copepods, and amphipods) and bristleworms (polychaetes). They capture prey by flying low above the water and dipping down with the bill, or sometimes diving into the water. Along shorelines, they wade or swim into shallow water to capture prey or pull items from tidepools. With hard-shelled prey, they fly up, then drop the animal onto rocks to break open the shell. They also consume algae (sea lettuce) and carrion along shorelines. When foraging on mudflats, they sometimes harass shorebirds for prey such as marine worms. On tundra nesting grounds, they eat the eggs of birds that nest in the vicinity, such as eiders, and also eat songbirds such as Lincoln’s Sparrows and Violet-green Swallows. In freshwater environments, they eat crayfish readily, capturing them by wading, swimming, and dipping the head deeply to retrieve the animal. In fields and pastures, they eat fly larvae, beetles and their larvae, ants, and earthworms, small mammals such as voles, and grains such as oats and corn. They also readily capture insects in flight, especially when abundant over farm fields.Back to top
Nests are set in a great variety of locations, the common theme being that they are difficult for predators to access and relatively sheltered from harsh weather: small islands, hummocks, boulder fields, trees, stumps, even rooftops.
The female constructs a cup of dry grass, conifer twigs (pine, cedar, hemlock), moss, lichens, roots, and bark. Nests range from 9.3 to 22 inches across and from 6.3 to 9.5 inches tall, with interior cup 5.5 to 11.4 inches across and 6.3 to 9.5 inches deep.
|Clutch Size:||1-5 eggs|
|Egg Description:||Light olive with variable amount of dark brown speckles.|
|Condition at Hatching:||Chicks semiprecocial at hatching; may leave nest cup in several days. Covered in cryptically colored down.|
Short-billed Gulls form long-term pair bonds, and many are already paired when they arrive back on the nesting grounds in spring. They nest in colonies, mostly in monogamous pairs, and defend the area around the nest against others of their species. Pairs perform courtship displays similar to other gull species. The female often initiates courtship by approaching the male and hunching down, walking around the male, and tossing the bill upward and calling, much as a chick would beg for food. She often then pecks the male’s bill, and he disgorges food directly into her mouth, called “courtship feeding.” This behavior is often followed by a so-called “choke” display, with neck stretched out and bill pointed downward, or a “long-call display,” with head raised vertically and wings held partly open. These behaviors help maintain the pair bond and also warn away other gulls that might approach their territory or food resources too closely. Both adults share incubation and chick-feeding duties. Once the young have fledged, most Short-billed Gulls move toward rivers and coastlines in preparation for the southward migration.Back to top
Short-billed Gull was only recognized as a full species in 2021, and there is little information on their population dynamics in North America. Partners in Flight rates the species a 12 out of 20 on the Continental Concern Score, indicating a species of relatively low conservation concern. In 2002, the North American Waterbird Conservation Plan estimated the North American breeding population of Common Gull (now recognized as Short-billed Gull) at 160,000-240,000 birds. Short-billed Gulls are vulnerable to the effects of oil spills, which damage their plumage, foul their habitats, and contaminate their prey.Back to top
Kushlan, J. A., M. J. Steinkamp, K. C. Parsons, J. Capp, M. A. Cruz, M. Coulter, I. Davidson, L. Dickson, N. Edelson, R. Elliott, R. M. Erwin, S. Hatch, S. Kress, R. Milko, S. Miller, K. Mills, R. Paul, R. Phillips, J. E. Saliva, W. Sydeman, J. Trapp, J. Wheeler and K. Wohl (2002). Waterbird conservation for the Americas: The North American waterbird conservation plan, version 1. Washington, DC, USA.
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
Moskoff, William and Louis R. Bevier. (2002). Mew Gull (Larus canus), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.