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
♦ ²Keitt, B.S., Tershy, B.R. & Croll, D.A. 2000. Black-vented Shearwater (Puffinus opisthomelas) In: Poole, A. & Gill, F. (Eds). The birds of North America. No. 521. Philadelphia & Washington, DC: Academy of Natural Sciences & the American Ornithologists’ Union.