Shearwaters eat small crustaceans, plankton, squid, fish, and in some cases, floating scraps.
Oodles more information at the related link listed below:
Most probably a Yelkouan Shearwater. Also known as a Mediterranean Shearwater
Shearwater Aircraft was created in 2009.
Sooty Shearwater was created in 1789.
Hutton's Shearwater was created in 1912.
Boyd's Shearwater was created in 1912.
Streaked Shearwater was created in 1835.
Newell's Shearwater was created in 1900.
Barolo Shearwater was created in 1857.
Dune Shearwater was created in 1990.
Bryan's Shearwater was created in 2011.
Audubon's Shearwater was created in 1839.
Townsend's Shearwater was created in 1890.