- 25.2–33.5 in
- 52–61 in
- 33.5–63.5 oz
- White-bellied Booby
- Fou brun (French)
- Boba prieta, Bubi chaleco (Spanish)
- The Brown Booby is the only ground-nesting booby that regularly builds a substantial nest.
- Like all boobies and pelicans, the Brown Booby's feet are "totipalmate," having webbing connecting all four toes.
- Brown Booby nests sometimes contain the bodies of dead Sooty Tern chicks.
- Male and female Brown Boobies generally look alike in plumage color, except in populations found along the Pacific Coast of Mexico and Central and South America. There the females look like those in other populations, but the males have light gray to white heads.
- The oldest recorded Brown Booby was a 26 year old male.
Nests on islands, covering a wide range of vegetation types, geologic features, and weather patterns. Found at sea in nonbreeding season.
Squid and fish, especially flying fish.
- Clutch Size
- 1–3 eggs
- Egg Description
- Pale bluish or greenish, with white outer layer.
- Condition at Hatching
- Blind and helpless.
Mound of branches, bones, grass, human-generated trash, or other items. Placed on flat ground, usually in full sunshine. Nests in colonies.
Plunge-dives from various heights up to 15 m (50 feet). Folds wings next to body at beginning of dive, then thrusts wings straight out over back, touching in the middle, just before breaking the surface. Dive may reach just below surface, or to as much as 2 m (6 feet) deep. Commonly feeds in areas where large predatory fish such as tuna drive smaller fish to the surface. Also follows fishing vessels.
Brown Booby populations are declining. The Waterbird Conservation for the Americas estimates a population of 280,000-300,000 breeders, rates the species a 14 out of 20 on the Continental Concern score, and considers it a Species of High Concern. Brown Booby are on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. Brown Booby no longer breeds on many tropical islands where predators have been introduced. Human population growth and development of islands have caused severe population declines over the past century in the Caribbean.
- Schreiber, E. A., and R. L. Norton. 2002. Brown Booby (Sula leucogaster). In The Birds of North America, No. 649 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- Waterbird Conservation for the Americas, Technical Services Committee, Waterbird Conservation Council. 2006. Status Assessment Spreadsheet - Factor Scores and Categories of Concern for Colonial Waterbirds.