150 Papers from the Marine Biological Laboratory at Tortugas. 



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 incubation ; but there appeared to be no regularity as to when male or 

 female should be on guard. 



The man-o'-war birds were less tame than the boobies and, as a rule, 

 left the nest when one approached to within 30 or 40 feet of them. When, 

 however, the}' were brooding newly hatched chicks they showed more 

 bravery. 



In most instances the gular pouch had faded from carmine to orange, 

 and only one individual was seen with the pouch inflated, as Fisher has de- 

 scribed it (/. c. ). As I attempted to approach this bird, the pouch was sud- 

 denly deflated. 



The man-o"-war birds were not seen to devour the young of their own 

 species, as they have been said to do ; nor were they observed to capture 

 young boobies. Occasionally they chased the adult boobies and made them 

 disgorge in the air, but evidently, in the main, they did their own purveying, 

 flying-fish being taken from the throat of one bird that was shot. 



The adults were not heard to utter a sound. 



THE NEST. 



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. 



THE EGG AND YOUNG. 



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

 eggs were found. The young are born 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 re- 

 laxing, are permitted to rest on the nest. Their whole attitude suggests ex- 

 treme dejection; 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 suggesting similar habits of the young brown pelican. 



THE DEVELOPMENT OF l'LUM.\GE. 



The newly hatched man-o'-war bird is without down, except upon the 

 tail, alula, and those portions of the forearm from which the remiges 

 grow. When fully developed, this natal down, while not so uniformly 



