English Name: Masked Booby
Scientific Name: Sula dactylatra
the Masked Booby, Sula dactylatra, is a large seabird of the gannet family, Sulidae. This species breeds on islands in tropical oceans, especially on the Galapagos islands, except in the eastern Atlantic; in the eastern Pacific it is replaced by the Nazca Booby, Sula granti, which was formerly regarded as a subspecies of Masked Booby (Pitman & Jehl 1998, Friesen et al. 2002).\
Description
This is the largest booby, at 81-91 cm length, 152 cm wingspan and 1500 g weight. Adults are white with pointed black wings, a pointed black tail, and a dark grey facemask. The sexes are similar, but the male has a yellow bill, and the female's is greenish yellow; during the breeding season they have a patch of bare, bluish skin at the base of the bill. Juveniles are brownish on the head and upperparts, with a whitish rump and neck collar. The underparts are white. Adult plumage is acquired over two years.
The Masked Booby is silent at sea, but has a reedy whistling greeting call at the nesting colonies. While on the breeding grounds, these birds display a wide range of hissing and quacking notes.
Behaviour
Masked Boobies are spectacular divers, plunging diagonally into the ocean at high speed. They mainly eat small fish, including flying fish. This is a fairly sedentary bird, wintering at sea, but rarely seen far away from the breeding colonies. However, Caribbean birds occasionally wander north to warm southern Gulf Stream waters off the eastern seaboard of the United States. More remarkably, there have been three Western Palaearctic records of Masked Booby, presumably dactylatra, all from Spanish waters, although one of these also entered French territorial areas.