SULA. 205 



"A still more adult bird has a large amount of white or partially 

 white feathers mixed with the brown of the back and wings. 



"I should imagine that the fully adult plumage is not attained until 

 the third or perhaps the fourth year. This species may be recognized in 

 all stages of plumage by the hoary gray appearance on the outer webs of 

 the quills." (Grant.) 



169. SULA LEUCOGASTRA (Boddaert). 

 BROWN BOOBY. 



Pelecanus leucogaster BODDAERT, Tabl. PI. Enl. (1783), 57. 



Sula sula GRANT, Cat. Birds Brit. Mus. (1898), 26, 436; SHARPED Hand- 

 List (1899), 1, 237; MCGREGOR and WORCESTER, Hand-List (1906), 

 40; GATES, Cat. Birds' Eggs (1902), 2, 212; WORCESTER, Phil. Jour. 

 Sci. (1907), 2, sec. A, 275. pi. 1 ( Didicas Rocks ). 



Sula leucogaster BLANFORD, Fauna Brit. Ind. Bds. (1898), 4, 346, fig. 80 

 (head). 



Sula leucogastra A. O. U. COMMITTEE, Auk (1908), 25, 359. 



Batan (McGregor)-, Calayan (McGregor); Didicas Rocks (Worcester) ; Dina- 

 gat (Everett)-, Luzon (McGregor); Mindanao (Cumdng, Everett). Tropical 

 Atlantic, Indian, Australian, and Pacific Oceans. 



"Adult. Head, neck, chest, entire upper parts, wings, and tail dark 

 sooty brown; breast, rest of the under parts, axillars and under wing- 

 coverts of the secondaries pure white. Tail composed of 14 feathers. 

 Iris silvery white, white, or gray; bill whitish green or greenish blue, 

 becoming flesh-colored or bluish at the base; naked skin on sides of face 

 and gular pouch bluish, greenish, or yellowish; legs and feet pale green 

 or lead-green, sometimes inclining to yellowish. 



"Adult male. Length, about 711 ; culmen from feathers on forehead, 

 100; wing, 389 to 396; tail, 190 to 195; tarsus, 46 to 48. 



"Adult female. Length, about 711; culmen from feathers on forehead, 

 100; wing, 389 to 396; tail, 190 to 195; tarsus, 46 to 48. 



"Immature in first plumage. Differs in having the head, neck, chest, 

 entire upper parts, wings and tail brown, much lighter than in the adult ; 

 breast, belly, and under parts still paler brown, the feathers fringed with 

 whitish brown, and generally sharply defined from the darker chest; 

 axillars and secondary under wing-coverts mixed with smoky brown. 



"More mature birds ( ? plumage of the second year) . Breast, belly, 

 and under parts largely mixed with white, only the subterminal portion 

 of each feather smoky brown. 



"Still more mature bird ( ? plumage of the third year) . Head, neck, 

 chest, and upper parts darker brown, and more like those of the adult; 

 the breast and belly thickly mixed with the pure white feathers of the 

 adult. These appear to be entirely attained by molt, many half-grown 

 ones being concealed beneath the plumage." (Grant.) 



This gannet is quite abundant about the small islands north of Luzon 



