|
- Connect with the birding community
- Post your sightings for all to see
- Find interesting birds in your area
- It's fun, easy and free!
Masked Booby
The Masked Booby, Sula dactylatra, is a large seabird of the gannet family, Sulidae. It nests in small colonies, laying two chalky white eggs on sandy beaches, which are incubated by both adults for 45 days. Normally only one chick fledges.
This species breeds on islands in tropical oceans, except in the eastern Atlantic; in the eastern Pacific it is replaced by the Nazca Booby, Sula granti, which was formerly regarded as a race of Masked Booby.
There are three subspecies, none of which is separable at sea:
*S. d. personata breeds in the central and western Pacific and off Australia
*S. d. dactylatra breeds in the Caribbean and some Atlantic islands including Ascension Island. It has recently started breeding off Tobago, formerly being known in this area only from a single sight record from an oilrig off Trinidad.
*S. d. melanops is the form breeding in the western Indian Ocean
This species is fairly sedentary, 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.
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. 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.
Masked Booby is silent at sea, but has a reedy whistling greeting call at the nesting colonies.
Masked Boobies are spectacular divers, plunging diagonally into the ocean at high speed. They mainly eat small fish, including flying fish.
References
* Harrison. Seabirds. ISBN 0-7470-8028-8
* Hilty. Birds of Venezuela. ISBN 0-7136-6418-5
* ffrench, Robert (2003). Birds of Trinidad and Tobago. ISBN 0-7136-6759-1