All species › Waders, gulls and terns › Skimmers, noddies, terns and gulls › Western Gull
Position in the tree Birds Aves › Birds with a flexible palate Neognathae › All other modern birds Neoaves › Birds of the elements Elementaves › Cranes and waders Gruimorphae
Western Gull | Larus occidentalis
Pacifische mantelmeeuw | Gaviota occidental
The Western Gull is a large, dark-grey gull found almost only along the Pacific coast of North America, rarely far from the sea. In the guide area the species breeds on islands and rocky coasts on the Pacific side of Baja California, where it is present all year. Young birds take four years to acquire adult plumage.
Voice
A low, hoarse kyow and series of laughing calls, lower and coarser than those of American Herring Gull; at the colony also a short, repeated kak-kak-kak.
Recording: Thomas G. Graves — CC BY-NC-SA 4.0 · converted to mono · xeno-canto
Identification
55–66 cm, a large, heavy gull with a thick yellow bill with a marked angle on the lower mandible and a red spot, pink legs and a pale yellow to dark eye. Adults have a white head and white underparts and a slate-grey mantle and wings, with black wingtips with small white spots and a broad white trailing edge. The birds in Baja California belong to the subspecies L. o. wymani, which is darker grey than birds further north. The head stays almost white outside the breeding season as well. Juveniles are dark grey-brown with a black bill and gradually acquire a grey back.
Confusion species
Yellow-footed Gull Larus livens is very similar but has yellow legs and lives almost only in the Gulf of California, where Western Gull is rare. Lesser Black-backed Gull Larus fuscus is slimmer, with yellow legs and longer wings. American Herring Gull Larus smithsonianus and California Gull Larus californicus have a much paler grey mantle. Hybrids with Glaucous-winged Gull Larus glaucescens occur and have a paler mantle and greyer wingtips.
Habitat
Rocky coasts, islands and sandy beaches, coastal waters and bays, harbours and rubbish dumps near coastal towns. Breeds in colonies on rocky islands and cliffs. Feeds on fish, intertidal invertebrates, eggs and chicks of other seabirds and refuse; rarely forages inland.
Where the bird is most at home, classified by the vegetation units of Mexico and Central America.
Range and movements
Breeds along the Pacific coast of Baja California, on islands and rocky coasts from the Coronado Islands south to about the middle of the peninsula. Outside the breeding season spread along the whole west coast of the peninsula to Cabo San Lucas, and in smaller numbers in the southern Gulf of California and along the coast of Sonora and Sinaloa. Further south, from Nayarit to Oaxaca, rare, with single records in Central America to Costa Rica and Panama. Outside the guide area the species breeds along the coast of Washington, Oregon and California.
- Resident
- dark = core range, pale = thinly spread
How and when to look
Harbours and rocky coasts on the Pacific side of Baja California, such as at Ensenada, offer the best chance all year. The dark mantle, pink legs and heavy bill together are the best features.
Conservation status
Not threatened globally. The range is small and the population fairly stable, but the colonies are sensitive to disturbance, introduced predators and changes in food supply at sea. In the guide area a resident and breeding bird.
Scientific name
Larus occidentalis | Audubon, 1839
Audubon described the species in 1839 and placed it straight away in the genus where it still stands. The genus Larus was introduced in 1758 by Linnaeus. Larus is Latin, from Ancient Greek laros, and appears to have referred to a gull or another large seabird. occidentalis is Latin for 'western', after its range along the west coast of North America. The specimen the first description was based on came from Cape Disappointment, Washington.