Boobies are large and distinctive in shape with long slightly crooked pointed wings, fairly long necks that taper into a slender head and long pointed bill, with a lot of neck and head extension in front of the wing. The rump and tail extend well behind the wings tapering to a fairly narrow wedge-shaped tail that looks pointed in flight. This species is a bit smaller and proportionally shorter-winged and shorter-tailed than other sulids. Shows a solidly dark brown head, breast, back, wings, and tail in all plumages. Adults are white below from the lower breast to the under tail, with a sharp delineation between the dark brown and white at mid-breast. All yellow bill, females have yellow facial skin and males have blue-gray facial skin, bright yellow feet and legs. In flight, upperparts are entirely dark brown. Undersides of primaries and secondaries are also dark brown, while the axillaries and under wing linings are mostly white with a dark bar extending in from the wrist. Immatures entirely dark brown, though slightly paler from the lower breast to the under tail. Bill and facial skin very dark bluish-gray, feet and legs dull yellow. In flight, looks all dark brown except paler pale gray brown wing linings. Immature Masked Booby resembles adult Brown including a yellow bill, but is white instead of brown on the breast.

Length: 76 (cm) Wingspan: 145 (cm)

Voice:

At breeding colonies, female makes honks and grunts; male gives high, whistled notes.

Habitat:

Warm water species, found at sea except when nesting on islands with varying amounts of vegetation.

Behavior:

Often perches on towers or in trees. Plunge-dives for food.

Feeding:

Diet consists of fish, particularly flying fish, and squid.