ART. 10 BIRDS OF PINCHOT EXPEDITION FISHER AND WETMOEE 33 



pact and made of fine drift seaweed. An interesting question is why 

 this species is so unevenly restricted when so many suitable, widely 

 separated places exist; also why, with the exception of this small 

 colony, no cormorants were seen between Panama and the entrance 

 of San Francisco Bay on our long 7,500-mile trip through the South 

 Seas. 



FREGATA MAGNIFICENS Mathews 



Frigate bird, man-o'-war bird 



Fregata minor magnificens Mathews, Austr. Av. Rec, vol. 2, December 19, 

 1914, p. 120. (Barrington Island, Galapagos Archipelago.) 



A male and a female taken on Cocos Island June 5, 1929, by A. K. 

 Fisher, are immature birds, with the head, neck, and upper breast 

 suffused with brown. The light wing bar in both is pale, and stands 

 out in marked contrast to the darker feathers of the wing. 



Some form of this bird of wonderful flight was seen at every 

 island encountered between Cocos Island and Tahiti. 



They would often follow the yacht, soar above it, or even alight 

 on its higher rigging, and on occasion it was feared they might injure 

 the radio outfit by alighting on it. At Tower Island, every morn- 

 ing 50 or more females would leave the males to attend to the nests 

 and would fly out to the vessel to circle about in graceful curves for 

 a time and then return to the island. At the nesting colony on 

 Tower Island (pi. 6), the birds were easily approached, and after 

 a few preliminary half-hearted thrusts at the intruder, would 

 allow themselves to be stroked with the hand. On one occasion a 

 male, in his first excitement at being approached, disgorged some 

 fish that he evidently had taken from boobies. In feeding habits 

 they have two very dissimilar methods of procuring food, namely, 

 as robbers and as scavengers. As pirates they rob other birds of 

 fish just captured, and as scavengers they pick morsels from the 

 ocean surface. "Wlien taking food from the water the wing tips 

 are thrown upward with wonderful grace as the bird poises for a 

 moment, while reaching downward with extended neck. The booby 

 appears to be the most frequent victim upon which these great birds 

 practice piracy. When boobies find shoals of fish and are feeding in 

 numbers, the man-o'-war birds are sure to be hovering near to secure 

 their unjust share of the chase. Some individual boobies seem to 

 have acquired prudence, and after catching fish, remain on the 

 surface long enough to be forgotten by their persecutors before tak- 

 ing wing to resume their pursuit of food. The man-o'-war bird also 

 robs the noddy, and at times pursues the little stormy petrel. The 

 question is whether the petrel also would be devoured if the man-o'- 

 war should catch up with it. 

 51730—31 3 



