The name Alcatraz Island originates from a name given to one of the islands in San Francisco Bay during Spanish rule of California, La Isla de los Alcatraces.
That translates to ‘The Island of the Gannets’ but it is widely suggested that the original meaning was ‘The Island of the Pelicans’, based on an archaic Spanish word for pelican, alcatraz. It is documented that there were populations of brown pelicans inhabiting the Bay’s islands.
The name is credited to Spanish naval officer Juan Manuel de Ayala who charted San Francisco Bay in 1775. Although it is suggested that Ayala’s original charts ascribed the name to what is now Yerba Buena Island and at some point in history it instead became attached to the present day Alcatraz Island.