LIFE HISTORIES OF NOKTH AMERICAN PETRELS AND PELICANS. 309 



I have visited the breeding places of many sea birds before, and some well 

 worth the trouble, but none so interesting to me as this. It was a most 

 singular spectacle. Thousands and thousands of these great and ordinarily 

 wild birds covered the whole surface of the prickly pears as they sat on their 

 nests or darkened the air as they hovered over them, so tame that they would 

 hardly move on being touched ; indeed, the specimens that I procured were all 

 taken alive witli my own hands. When I had penetrated as far among them 

 as possible, I fired my gun ; the whole colony rose at once, and the noise made 

 by their long and powerful wings striking against each other was almost deafen- 

 ing. In a moment they commenced settling upon their nests and were soon 

 as quiet as before. 



From Dr. Frank M. Chapman's (1908a) contribution to the life 

 history of this species, in the Bahamas, I quote as follows : 



The luxuriant growth of cactus among the sea grapes in which the man-o'-war 

 birds nested added to the difficulty with which these thickly branched, shrubby 

 trees were penetrated, and we did not attempt to make a census of the number 

 of birds of this species which were breeding on Cay Verde. We estimated, how- 

 ever, that there were between 200 and 300 pairs. 



The man-o'-war birds awoke at about the same time as the boobies and at 

 5.30 a. m. were sailing over their rookery. From this time until they retired, 

 considerably before the boobies, and while it was yet light, a flock of birds 

 was constantly over the sea grapes. The birds may be said to have perched 

 in the air above their homes. Only one bird is in attendance on the young at 

 the same time. Both sexes assumed this duty, as well as the task of incuba- 

 tion ; but there appeared to be no regularity as to when male or female should 

 be on guard. 



The nests are frail, open-worked, slightly hollowed platforms, composed of 

 small sticks and twigs placed in the tops of the sea grapes, at a height of 6 or 7 

 feet, or among the cactuses within 2 feet of the ground. Several nests are 

 often placed in one bush within reaching distance of one another. They become 

 matted with filth as the young increase in size. One adult was seen carrying 

 nest-building material in its bill. 



Eggs. — The man-o'-war bird lays but one egg, which is approxi- 

 mately "elliptical ovate" in shape and pure dead white in color. 

 The shell is very thin for an egg of its size, smooth and lusterless. 

 The measurements of 60 eggs, in several collections, average 68.4 by 

 46.5 millimeters ; the eggs showing the four extremes measures 74 by 

 48.5, 72.5 by 50, 64.5 by 46, and 66.5 by 43.5 millimeters. 



Young. — Doctor Chapman (1908a) says of the development of 



the young : 



The man-o'-war bird lays but one egg, and in a number of nests fresh eggs 

 were found. The young are bom naked and are brooded by the parents. As 

 they increase in size and become covered with white down, their wings seem 

 to be much too large for them to hold close to the body, and relaxing are 

 permitted to rest on the nest. Their whole attitude suggests extreme de- 

 jection ; not only do the wings droop, but the head often hangs over the edge 

 of the nest. When approached they utter a squealing, chippering call, and 

 snap their bills with a rattling sound, both the note and action strongly sug- 

 gesting similar habits of the young brown pelican, 



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