These large seabirds are spectacular divers, plunging into the ocean at high speed to catch fish and squid.
Brown boobies are chocolate-coloured with pale bellies and underwings. They can grow up to 75 cm in size.
They are powerful and agile flyers, but can appear awkward when taking off and landing.
Brown boobies are ground nesters, gathering in colonies to build simple nests. They occupy the nest site year round and can breed at any time, laying one or two eggs and rearing only one chick.
There are as many as 7,000 breeding pairs on Christmas Island, one of the world’s largest populations of these impressive birds.
Brown booby with chick. Photo: Wondrous World Images
Where to see them
You’ll see brown boobies nesting on sea cliffs, coastal terraces and some inland cliffs.
Sula leucogaster plotus