Brown Booby

Overview

The brown booby (Sula leucogaster) is a large seabird in the family Sulidae and one of the most common and widespread species within it. This gregarious bird has a pantropical range that overlaps with other booby species.

Identification

• Dark brown to blackish plumage on the head and back, contrasting with a white belly.
• Females measure up to 80 cm in length with a wingspan of up to 150 cm, while males reach 75 cm and 140 cm respectively.
• Males possess a blue orbital ring, distinguishing them from females which have yellow rings.
• Typically silent, but occasionally emits grunting or quacking sounds.

Habitat

This species breeds on islands and coasts across the pantropical Atlantic, Indian, and Pacific Oceans, including areas such as the Gulf of Mexico and the Caribbean Sea. It winters at sea over a wider area, and with global warming has increasingly moved north into previously too-cold seas.

Diet

Brown boobies primarily eat small fish such as flying fish, mullets, and anchovies, as well as squids and shrimps, which they catch by plunge-diving at high speed or skimming the surface. Some individuals also practice kleptoparasitism, stealing prey from other seabirds, including great frigatebirds.

Did you know?

Due to rising pollution levels, brown boobies have begun using marine debris to construct their nests, with one study finding that 90.1% of these nests consisted of plastic.