200 BULLETIN 121, UNITED STATES NATIONAL. MUSEUM. 



Food. — The food of this booby consists principally and probably 

 wholly of fish. JMr. Gilford (1913) describes the methods employed 

 as f olloAvs : 



The fish were almost invariably caught by tlivinp:, although an occasional 

 flying fish was chased and caught while in the air. It was a common thing to 

 see blue-footed boobies fishing in flocks, often all diving simultaneously. They 

 dive with wings half closed and neck rigid and straight, striking the water with 

 great force. As all would not get fish when diving in a flock, there was usually 

 considerable squabbling over captures. One day a booby was seen to enter the 

 water obliquely at a very small angle, appearing quickly on the surface again 

 and continuing its line of flight without a pause. 



Behavior. — The same waiter says of its actions : 



When offshore and on a journey, the blue-footed boobies frequently flew in 

 single file, all following the undulations of the leader. On the south coast of 

 Albemarle Island, in May, they were noted flying toward Brattle Island each 

 evening. Single birds met with offshore usually circled about the schooner. 

 The birds noted about the bays and coves had the habit of continually looking 

 downward when flying, apparently in search of fish. 



When not fishing, the blue-footed boobies frequently congregated on the low 

 black lava points which jut into the sea, the assemblages varying from two or 

 three to thirty or forty. Single birds and pairs are often seen standing on the 

 ledges and on the tops of sea cliffs. On south James they were seen in the 

 mangroves. It was not unusual to find them asleep in broad dnylight. An 

 entire fiock, however, was never caught napping, two or three birds always 

 being awake and on the lookout. 



As to the migrations and the habits of the blue-footed booby Avhen 

 absent from its breeding grounds, I can not find that anything has 

 been published. 



DISTRIBUTION. 



Breeding range. — From the Gidf of California (San Pedro Martir 

 Island) south along the west coast of Mexico (Tres Marias Islands), 

 the Revillagigedo Islands (Clarion Island), the Galapagos Islands, 

 and on the coast of Peru (Lobos de Tierra Island). 



AVinter range. — Mainly near its breeding grounds. Ranges south 

 to Chile. 



Egg dates. — Mexican islands : TAventy-niiie records, March 7 to 

 May 21; fifteen records, April 10 and 11. 



SULA LEUCOGASTRIS (Boddacrt). 

 BOOBY. 

 HABITS. 



The common brown booby, or white-bellied booby, often called 

 the brown gannet, is a widely distributed species among the islands 

 of the tropical seas of both hemispheres. At the present time it is 

 known to be a North American bird merely as a straggler or an 



