Skip Navigation

Masked Booby

Sula dactylatra / ‘A
Masked Booby
Largest of the boobies, adult birds are white with dark brown or black flight and tail feathers. Bill color is yellow and feet are yellowish gray. Facial skin is gray-black. Sexes are similar in appearance. Juveniles are generally grayish brown with white underparts. Adult plumage is attained by the third year.

Breeding season occurs between February and August. Nests are located on the ground and consist simply of a shallow depression. They begin breeding at four years of age and are monogamous. Two chalky white eggs are laid. They lack a brood patch and instead incubate with their feet. Parents share incubation duties and the average incubation shift is 9.5 hours. Incubation period averages 43 days. The first egg hatches four to nine days before the second and the first chick to hatch ejects the second chick from the nest shortly after it emerges from the egg. Chick feeding occurs once or twice a day. Fledging occurs 109-151 days after hatching. Post fledging care and feeding continues for one to two months.

Facts About Masked Booby

Diet
Feeds by plunging head first into the water from the air, sometimes diving from as high as 30 m. Feeding areas are usually many miles from land and feeds primarily on fish and squid. Feeding generally occurs during daylight hours.
Life Span
20 years
Size
Length: 74-86 cm (29-34 in); wingspan: 152 cm (62 in)
Page Photo Credits — © Dan Clark
Last Updated: Aug 23, 2013
Return to main navigation