Masked Booby (species: Sula dactylatra) in Birds of Costa Rica (Gaia Guide)
Sula dactylatra
Masked Booby


©Tony Morris: Masked Booby (Sula dactylatra)

©NSW Government: Masked booby with chick
Kingdom Animalia
Phylum Chordata
Class Aves
Order Pelecaniformes
Family Sulidae
Genus Sula
Species Sula dactylatra
Status least concern

Colours

                   

Distinguishing features

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. (Wikipedia)

Size

  • From 74 cm to 91 cm (Length of specimen)

Weight

  • From 1.2 kg to 2.35 kg

Wingspan

  • From 137 cm to 165 cm

Synonyms

Interesting facts

  • It nests in small colonies, laying two chalky white eggs on sandy beaches in shallow depressions, which are incubated by both adults for 45 days. In most cases, the first chick will kill its smaller, weaker sibling after it hatches. While the boobies can manage to feed two chicks if siblicide is prevented, they do so at a steep penalty to health and future reproductive success. (Wikipedia)

Distribution


©Atlas of Living Australia: Australian distribution

Distribution and habitat preferences

It breeds on islands in tropical oceans, except in the eastern Atlantic. 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. (Wikipedia)

Audio recordings


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Male, in breeding colony

© Robson Silva e Silva
(source)

Diet

They are spectacular divers, plunging diagonally into the ocean at high speed. They mainly eat small fish, including flying fish. (Wikipedia)

Web resources