Although the Herring Gull is one of the most commonly seen gulls over most of North America, it is not easy to find in the Rockies. As a bird of ocean coasts and large lakes, the large Herring Gull finds little suitable habitat in the mountains. The Herring Gull is a wonderfully adaptive species over most of its range, and its population has increased as a result of human development. Herring Gulls also occur in Europe and parts of coastal Asia. The Herring Gull, like many gulls, has a small red spot on its lower mandible that serves as a target for the young. When a downy chick pecks at the lower mandible, the parent instinctively feeds it by regurgitation. Prior to obtaining their full adult plumage and color, Herring Gulls go through no less than seven changes of brownish plumage. The scientific name argentatus is Latin for 'silvery,' probably in reference to this bird's back or underwing.
I.D.: Sexes similar: large gull; yellow bill; red spot on the lower mandible tip; light eyes; light gray back; black wing tips; pink legs. Breeding: white head; white underparts. Non-breeding: white head and nape is washed with brown. Immature: mottled brown.
Size: L 23-26 in. (58-66 cm);
W 58 in. (147 cm).
Range: rare, but regular, migrant throughout the Rockies.
Habitat: In migration: large lakes, wetlands, rivers, landfills and public areas throughout the montane.
Nesting: in Canada and Alaska; colonial, often with other gulls, pelicans and cormorants; usually on the ground on open beaches, islands or shorelines; in a shallow scrape lined with plants and sticks; pair incubates 3 eggs for 31-32 days.
Feeding: very opportunistic, generalist feeder; surface tips for aquatic invertebrates and small fish; gleans the ground for insects and worms; scavenges dead fish and garbage at landfills; also eats other birds' eggs and young.
Voice: loud, bugle-like kleew-kleew; also an alarmed kak-kak-kak.
Similar Species: California Gull : much smaller; dark eyes; green legs. Ring-billed Gull: black ring around the bill; smaller.