South Dakota
Birds and Birding
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Brown Booby

Sula leucogaster

Length: 30 inches Wingspan: 58 inches Seasonality: Non-resident in South Dakota
ID Keys: Dark brown upperparts, head, neck, and breast; white belly; bright yellow feet

Brown Booby - Sula leucogasterThe Brown Booby is a widespread Booby species, with nesting colonies found on islands throughout the tropical oceans of the world. They are just visitors to the United States, with most sightings seen near the Dry Tortugas in Florida, but with widespread sightings along both coasts, and a handful of sightings on inland areas.  They are easily differentiated from other Booby species by the stark contrasting brown and white plumage, as they are the only Booby species with a dark brown back, head, neck, and breast, with a strongly contrasting white belly.

Habitat: Nesting colonies are on tropical islands.  Outside of the breeding season, some birds may disperse, and may be found anywhere from close to shore, to very far out at sea.

Diet: Feeds mostly on fish, but will also take squid and other marine life on occasion.

Behavior: Forages by plunge-diving into the water in pursuit of prey.  They will also sometimes swim on the ocean's surface and grab food items while swimming.

Nesting: Brown Boobies build a mounded nest of sticks, grasses, and various types of debris, placed directly on the ground, or sometimes on a ledge on a cliff face.  The female lays 1 or 2 eggs, and both parents help to incubate them.  Upon hatching, both parents help feed the nestlings, with parents continuing to care for the young for 4 months or more.

Song: At breeding colonies, young and females make groaning and honking sounds, while males have a higher-pitched whistling sound.  Brown Boobies are usually silent when not at breeding colonies.

Migration: Near breeding colonies, Brown Boobies are often found year round, but with birds wandering further out to sea than during the breeding season.  Some birds may widely disperse after breeding.

Similar Species: Dark upper plumage and dark head with white belly is unique for adult booby species. Most likely to be confused with Blue-footed Booby at a distance.

Conservation Status: Populations have declined somewhat in the last several decades, as introduced predators such as rats wiping out some former nesting colonies.  However, nesting colonies are numerous and widespread throughout the tropical oceans, and overall populations still remain strong.  The IUCN lists the Brown Booby as a species of "Least Concern".

Further Information: 1) Hawaii Guide - Brown Booby

2) eNature.com - Brown Booby

3) U.S. Fish and Wildlife Midway National Wildlife Refuge - Brown Booby

Photo Information: Photo taken by "Mike's Birds" - Licensed under Creative Commons Attribution ShareAlike Generic 2.0 License.

 

Click below for a higher-resolution map
Brown Booby - Range Map
South Dakota Status: Non-resident in South Dakota
 

Additional Brown Booby Photos (coming soon!!)