The strikingly marked Heerman's Gull is common along the West Coast of the United States. This gray-bodied, white-headed gull breeds in Mexico and then moves north along the Pacific Coast to southern British Columbia.

Interesting Information

• The Heerman's Gull, like many other gulls, frequently steals food from other birds. The Brown Pelican is a frequent victim. An adult Heerman's Gull is most likely to try to steal food from an adult pelican, and an immature gull is more likely to steal from an immature pelican.

• The Heerman's Gull is the only North American gull that breeds south of the United States and comes north to spend the nonbreeding season. After breeding is over in July, the gull quickly comes north all the way to southern Canada. It heads back southward by December, and most breeders are at the breeding islands by March.

• Perhaps as a result of the increasing populations in Mexico, several attempts have been made by Heerman's Gulls to breed in California. The first was on the island of Alcatraz. So far these attempts have been unsuccessful, but eventual successful nesting is expected.

Description

Immature

Juvenal plumage: Uniformly sooty brown all over. Buff edge to feather tips, giving scaly look. Bill two-toned, with pale flesh base and black tip. Eyes dark. Legs black.

First winter (Basic I): Uniformly sooty brown all over. Bill two-toned, with pale flesh base and black tip. Eyes dark. Legs black. Wing feathers and tail black.

Second winter (Basic II): Body sooty gray. Head and nape slate black. Eyes with thin, pale white crescents above and below. Secondaries and tertials dark with white tips. Tail black with narrow white band at tip.

Second summer (Alternate II): Imperfect whitish hood. Body sooty gray. Eyes with thin, pale white crescents above and below. Secondaries and tertials dark with white tips. Tail black with narrow white band at tip.