Charadriiformes / Laridae / Larus
Short-billed Gull
Larus brachyrhynchus · 美洲海鸥
Introduction
A gull species breeding in northwestern North America, previously considered conspecific with the common gull. Recognized as a distinct species by the American Ornithological Society in 2021 based on genetic, plumage, morphological, and vocal differences.
Description
Length 40–45 cm (16–18 in); wingspan 100–120 cm (39–47 in). Smaller than other gulls in the Common gull complex, with a shorter bill and longer, narrow-appearing wings. Breeding adults have a white head, pale eyes with red orbital skin, and unmarked yellow legs and bill. Winter adults show brown head mottling, grayish orbital skin, and a duller bill with faint dark marking. Flight feathers p9 and p10 have conspicuous white mirrors; p5–p8 have white 'tongue tips' forming a 'string of pearls' leading to a broad white trailing edge; p4 often has black markings. Juveniles are brownish overall with dark brown wingtips and smudged head/neck. First-year birds may develop grayish saddle feathers; bill becomes pink-based with black tip. Second-year birds resemble adults but retain brown wing coverts and black tertial markings, lacking white spots except on p10. Third-year birds may show dark markings on primary coverts, secondaries, underwing, and tail.
Identification
Distinguished from the common gull by a smaller bill, longer wings, and specific wingtip patterns: larger white mirrors on p9–p10, white 'tongue tips' on p5–p8, and frequent black markings on p4. Common gulls have more extensive black wingtips, smaller mirrors, narrower trailing edges, and typically lack black on p4 or white tongue tips on p8. Juveniles are darker and more smudged than the paler, finely-marked juvenile common gull.
Distribution & Habitat
Breeds in colonies along coastal areas and inland wetlands in Alaska and Northwest Canada. Winters mainly along the Pacific coast to the Sacramento Valley, less frequently to Baja California, the Northern Rockies, and Ontario. Very rare in eastern North America and vagrant to east Asia. Recorded in Europe twice: Azores (2003) and Faroe Islands (2026).
Behavior & Ecology
Takes three years to attain full breeding plumage.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Charadriiformes
- Family
- Laridae
- Genus
- Larus
Distribution
breeds Alaska mainland eastward to northwestern Alberta and southward to southwestern British Columbia (southwestern Canada); winters Pacific coast from southern British Columbia southward to northwestern Baja California (northwestern Mexico)
Vocalizations
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Bird images and sounds sourced from GBIF, contributed by citizen scientists worldwide under Creative Commons licenses.
Taxonomy data from AviList 2025.
