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
♦ ²del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.