A Western Gull is a relatively large, white headed and dark backed gull. It is found in large numbers on western coast of North America. Formerly it was considered similar to the Yellow-footed Gull. The population of Western Gulls ranges from Washington and British Columbia to Baja California.
Western Gulls are large in size. They have white head and body with grey wings. It is around 60 cm in length. They have yellow colored bill with a red subterminal spot. Western Gull somewhat look like a Slaty-backed Gull. Also they are closely related to the Glaucous-winged Gulls. They form a hybrid zone with Glaucous-winged Gulls in its north range.
The Western Gulls loves to live above the open sea and are rarely spotted at inland. They build their nests on rocky coasts, offshore islands and on islands inside estuaries. Western Gulls are colonial birds. The long term pair of the colony protects the territory. The borders of the territory may shift by year.
During the breeding time, the bird builds a nest of vegetation and lays three eggs. It incubates the eggs for a month. A young bird lives in the nest until it gets full fledged. hick wandering or lost in another territory has the danger of being killed by the territory's pair. However, sometimes the abandoned chicks will be adopted by other gulls.
Western Gulls lives on eating fish, squid, jellyfish and krill. However on land they feed seal , sea lion carcasses, snails, cockles, and limpets. They also use human altered habitats for feeding. They take the wasted food from beaches and marinas thrown by people. Sometimes they also eat the young and even adult of other sea birds.
Western Gulls generally lives for 15 years, but can live up to 5 years.