Attributes / relations provided by
♦ ¹Species- and sex-specific differences in foraging behaviour and foraging zones in blue-footed and brown boobies in the Gulf of California, Henri Weimerskirch, Scott A. Shaffer, Yann Tremblay, Daniel P. Costa, Hélène Gadenne, Akiko Kato, Yan Ropert-Coudert, Katsufumi Sato, David Aurioles, Mar Ecol Prog Ser 391: 267–278, 2009
♦ ²Food Web Relationships of Northern Puget Sound and the Strait of Juan de Fuca : a Synthesis of the Available Knowledge, Charles A. Simenstad, Bruce S. Miller, Carl F. Nyblade, Kathleen Thornburgh, and Lewis J. Bledsoe, EPA-600 7-29-259 September 1979