Heermann's gull  (Larus heermanni)

Heermann's gull breeds off the coast of Mexico and in the Gulf of California, particularly on Isla Rasa, where the population has a stronghold. Very occasionally it is seen breeding in San Francisco Bay (2). Non-breeders spend the breeding season at the wintering sites along the coasts of California and British Colombia (3).

This coastal gull prefers beaches, rocky shores, estuaries and lagoons for foraging and breeding, and will often nest on offshore islands. During the winter it moves out to sea or remains in remote coastal areas (2) (3).