The Heermann's gull (Larus heermanni) is a gull resident in the United States, Mexico and extreme southwestern British Columbia, nearly all nesting on Isla Rasa in the Gulf of California. They are usually found near shores or well out to sea, very rarely inland. The species is named after Adolphus Lewis Heermann, nineteenth-century explorer and naturalist.[2]
This species looks distinctly different from other gulls. Adults have a medium gray body, blackish-gray wings and tail with white edges, and a red bill with a black tip. Calls are described as deep and similar in pattern to other gulls but noticeably different in quality. The white head and upper neck contrasting with the grey-black wings is striking.
Heermann's gull sometimes steals prey from other seabirds, particularly brown pelicans, with which it often associates.