BIRDS OF PORTO RICO. 19 



about 2,000 in all, were gathered in a close colony 200 feet above the water 

 among growths of West Indian birch (Elaphrium simarubra) and other shrubs. 

 The adults in white plumage were very conspicuous and were much wilder 

 than either the young or the other species of booby. From 8. leucogastra 

 they can readily be distinguished by their smaller size, even on the wing. 

 Second-year birds in a grayish plumage with white tail and undertail coverts 

 were seemingly in pairs and ready to nest. These birds were much lighter 

 on the wing than the larger species and rose with less effort. Their general 

 habits were the same as those of the larger bird. They have not been recorded 

 from Porto Rico before, though Bowdish (1902-3, p. 358) noted that there 

 may have been a second species of booby on Desecheo Island at the time of 

 his visits. 



There is some uncertainty as to the breeding period of the two species of 

 boobies here. Native fishermen say that they nest in October or December, 

 while W. W. Brown, jr. (Cory 1892a, p. 229), found them nesting on Mona 

 in February. From the condition of plumage in some of the young birds, 

 they might have been hatched about that time, but others were evidently older. 

 It is probable that some of the birds nest irregularly throughout the year, as 

 the seasons are not sharply defined. In food and economy this species does 

 not differ essentially from the common booby. 



BOOBY. Sula leucogastra (Boddaert). 

 Pajaro Bobo, Buguere. 



A booby rookery is reported on some rocky islets between Culebrita Island 

 and Cayo Norte, the birds coming in the last of April and nesting through 

 May and June. Men are said to gather their eggs occasionally, but the birds 

 are probably not much disturbed. These birds are protected by law, as the 

 small islands surrounding Culebra.have been set aside as a national bird reser- 

 vation and as such are under the jurisdiction of the United States Department 

 of Agriculture. 



Boobies are found at times along the coast of Vieques Island also, and on 

 Desecheo Island this species is the most abundant bird, a conservative estimate 

 made in June placing its numbers at from 8,000 to 10,000. These birds are said 

 by the fishermen to nest here from late June until October, and a few were 

 seen playing with sticks and straws as though contemplating nest building, 

 So-called sportsmen have visited Desecheo occasionally and shot these help- 

 less birds merely to see them drop. The veriest tyro can hardly miss one 

 even on the wing. They are unfit for food, and, having little fear, circle 

 repeatedly over those already killed. 



Field examinations of stomachs of boobies showed only remains of fish, 

 though marine invertebrates doubtless are taken to some extent. Passing 

 their lives about these remote islands, the fish eaten by them are of little or 

 no economic importance, even though the birds are numerous. The colonies 

 here are now safe under Federal protection, and the birds should maintain 

 their numbers. 



MAN-O'-WAR BIRD. Fregata magnificens Matthews. 

 RABIJUNCOj Rabihorcado, Tijerilla. 



The rabijunco is well known to the fishermen around the coast line of Porto 

 Rico and its appearance is supposed by some to presage a storm. About 

 Vieques and Culebra Islands they were occasionally noted soaring high over 

 the ocean, usually well out from land. At Culebra, on April 11, one flew down 

 and picked up a dead tropic bird which I had shot, but dropped it after carry- 

 ing it a few feet. On another occasion in half a gale one flew over the town 



