About Sula sula (Linnaeus, 1766)
The red-footed booby, with the scientific name Sula sula (Linnaeus, 1766), is the smallest member of the booby and gannet family. It reaches approximately 70 cm (28 in) in length, with a maximum wingspan of 152 cm (60 in). An average weight of 837 g (1.845 lb) was recorded from a sample of 490 adult individuals collected from Christmas Island. This species is identifiable by its red legs, and pink-and-blue bill and throat pouch. It has multiple distinct plumage morphs. For the white morph, most plumage is white, with the head often developing a yellowish tinge, and black flight feathers. The black-tailed white morph is similar to the white morph but has a black tail, and can be easily confused with the Nazca booby and masked booby. The brown morph is entirely brown overall. The white-tailed brown morph matches the brown morph in overall appearance, but has a white belly, rump, and tail. The white-headed and white-tailed brown morph has mostly white body, tail, and head, with brown wings and back. Different morphs of this species commonly breed with one another, but one or two morphs are dominant in most regions; for example, most red-footed boobies in the Galápagos Islands belong to the brown morph, though the white morph also occurs there. Males and females have similar appearances. Juveniles are brownish with darker wings and pale pinkish legs, while newly hatched chicks are covered in dense white down. The red-footed booby is widely distributed across the tropics of the Atlantic, Pacific, and Indian Oceans. In the Atlantic Ocean, it mainly occurs around the Caribbean islands. In the Pacific Ocean, populations live in the Galápagos Islands (mostly on Genovesa and San Cristobal) and in Hawaii on the island of Kauai. In the Indian Ocean, it occurs on Aldabra, the Seychelles, Rodrigues, the Maldives, the Chagos Archipelago, the Cocos (Keeling) Islands, and Christmas Island. This species has been extirpated from many islands due to the combined effects of introduced predators and human hunting; this includes the Glorioso Islands, Assumption Island, Tikopia, Henderson Island, the Marquesas Islands, the Society Islands, and Desecheo Island. It occurs as a vagrant in Sri Lanka, New Zealand, and the United Kingdom. Vagrant records of the red-footed booby have also become more frequent in the United States and Canada in recent years.
