Elegant Tern (Thalasseus elegans)

Northern California numbers vary from year to year. Prior to the 1950's this species was very rare in Northern California, but it is now regular north to Oregon sometimes even reaching Washington State and British Columbia in invasion years. Surges are usually correlated with warm-water El Nino events. These large terns breed mostly in the Sea of Cortez, particularly Isla Rasa, and at a few colonies in Southern California. After nesting they disperse along the coast. Controversial records of this species breeding in Western Europe have recently been confirmed by genetic testing. This species was formerly included in the genus "Sterna" and thought to be closely related to the Royal Tern (T.maximus). However recent molecular research places it as sister to the Sandwich Tern (T. sandvicensis).