The Masked Booby (Sula dactylatra) is a large seabird, resembling the Australian Gannet. The name always brings a smile to our faces and we often joke about masked and unmasked boobies on board our boat Take It Easy! We could not resist making this majestic seabird the subject of our #34 Bird Photography Challenge.
What does it look like?
The Masked Booby has a dazzling white plumage with black trailing edges to the wings, a black wedge-shaped tail, a dark grey facemask which gives it its name, and a long straight serrated yellowish bill. Juveniles are brownish on the head and upperparts, with a whitish rump and neck collar. The underparts are white. The Masked Booby is a large seabird, the largest of the booby family at 74-91cm long, with a 137 to 165cm wingspan. It has large, webbed, grey feet.
Did you know?
Although the Masked Booby regularly lays two eggs, it never raises two young. The first egg is laid four to nine days before the second, and the older chick always ejects the second from the nest! While this may seem cruel, forcing the younger chick out increases the chances of survival of the older chick and in the long run the species, because the parents are better able to care for one chick at a time. They do not protect or feed the ejected chick, and it is quickly scavenged by crabs, land birds, or frigatebirds.
How does it behave?
The Masked booby is a spectacular diver, plunging diagonally into the ocean at high speed, from heights of up to 30 meters. It mainly eats squid and small fish, including flying fish. It swallows its catch upon returning to the surface. Masked Boobies are known to associate with dolphins and schools of tuna who chase prey fish to the sea surface. Masked Boobies spend significant amounts of time resting on the ocean surface in feeding areas, rising into the air to join feeding flocks when prey is detected.
On land the Masked Booby displays territorial behaviour. These include out-posting, leaning forward, bill held high to mark its nest site against incoming birds, yes-no headshaking, also with the bill held upwards against approaching birds, and wing-flailing and jabbing against intruders at the nest.
The Masked Booby is a fairly sedentary bird, wintering at sea, but rarely seen far away from the breeding colonies. It lays two chalky white eggs on sandy beaches in shallow depressions, which are incubated by both adults for 45 days. Only the older chick survives as already mentioned.
Where is it found?
The Masked Booby can be found across the Pacific Ocean. It lives on the open sea, only coming on land to breed and raise its young. We observed a few at the Southern Barrier Reef at the Lady Musgrave lagoon and off North West Island, as well as at Lord Howe Island.
The photos of the adult birds were taken using a hand-held Canon 7Dii camera, and a Tamron 18-270 lens . Those of the juvenile booby were taken at Lord Howe with a Canon 60D. Click on any image to display in full screen.