LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 189 



and their single young were fouiul in a cavity, and I took one old bird to 

 skin that night, expecting to get the remaining parent and young the next 

 morning. On returning the next day, great was my astonishment to find the 

 two birds gone, and still 'further was it taxed when I found, after careful 

 search, the two birds in another cavity twenty tO thirty feet away. 



Plumages. — The downy young is covered below with short, thick, 

 white doAvn, and above with long, soft, silky down varying in color 

 from '-ecru drab" to "pale drab gray." The first plumage to be 

 acquired is, in a general way, similar to that of the adult; there 

 is more black on the head, forming an occipital crescent; the black 

 bars on the back are broader; there are no long, central tail feathers; 

 and the bill is yellow instead of red. How long this plumage is worn, 

 or at what season the adult plumage is assumed, I do not know. 



Food. — Mr. E. W. Gifford (1913) says of the food of this species: 



The food of the red-billed tropic-bird, as shown by the stomachs examined, 

 consists of fish and squids. These were very often disgorged by both young 

 and old when they were taken from their burrows. This species dives for 

 its food somewhat like a tern. 



Behavior. — Of its voice, he writes : 



Red-billed tropic-birds could be recognized at almost any time by their cry, 

 which is long and shrill and consists of a lot of short, high, rasping notes 

 given in quick succession. Birds flying about the nesting-places often gave it, 

 and birds disturbed on the nest also gave it. The young, when taken from the 

 nest, uttered the same cry, and I have even heard a young bird only a day or 

 so old give three or four notes of it when handled. 



Doctor Nelson (1899) says that "when disturbed on the nest their 

 cries are very shrill and strident, consisting of a series of short, 

 harsh, clicking, or rattling sounds something like the noise of an 

 old-fashioned watchman's rattle." 



The flight of the tropic-birds is said to be not unlike that of the 

 terns, with rapid wing strokes; they must be graceful birds on the 

 wing with their long tail feathers streaming in the wind. They are 

 said to soar very high in the air at times, far above the boobies 

 and frigate "birds. Mr. Beck (1904) thought that "their flight and 

 call as they wheeled and darted about the high cliffs closely re- 

 sembled that of the white-throated swifts in California." He also 

 says: 



" In this section of the world the tropic-bird wanders as far away from land 

 as the frigate bird. We found both this species and the red-tailed tropic-bird 

 more than 600 miles from any island." 



Mr. Gifford (1913) Avrites of tlie activities of the red-billed tropic- 

 bird as follows: 



During the breeding season at Daphne Island I saw l)irds circling about 

 holes on the hillsides withoiit beating their wings. Whenever they came 

 opposite certain holes they would flutter their wings to check their flight, and 



