BOOBY AND MAN-O'-WAR BIRD 217 



and with a ti'iiinpeting call hlare at us with open mouth. Nor 

 do they rely only on their voice for defence, but use their 

 bill effectively, and, as has been remarked, they possess with 

 the adult the somewhat ludicrous habit of venting their feel- 

 ings by picking up bits of stick and grass. 



Compared with other rookeries I have visited, the mor- 

 tality among young Boobies on Cay Verde (aside from 

 tlie prenatal mortality already referred to) was surprising- 

 ly small. This I attribute to the isolation of the Cay which 

 permits the birds to rear their young with little or no intru- 

 sion by man, whose presence even only as a visitor, results 

 in great confusion and consequent death among the young 

 of ground-nesting colonial birds. 



The young were fed on squids and fishes which in a more 

 or less digested condition they obtained by thrusting their 

 heads and necks down the parent's throat, a manner of feed- 

 ing counnon to all the Steganopodes with whose habits I am 

 familiar (including Pelicans, Man-o'-War Birds, Cormor- 

 ants, and Anhingas). I have not, however, seen the Tropic 

 Bird feed its young and it would be interesting to know 

 whether this tern-like member of the order employs a simi- 

 lar method. 



Evidently but one brood is reared since approximately 

 three months must elapse after the egg is laid before the 

 young bird can fly and care for itself. 



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 pene- 

 trated, and we did not attempt to make a census of the num- 

 ber of birds of this species which were breeding on Cay 

 Verde. We estimated, however, that there were between 

 two hundred and three hundred pairs. 



The nesting season seemed to be about as far advanced 

 as it was with the Booby, most of the nests containing half- 

 grown young, but some held fresh eggs, while a few birds of 

 the year were already on the wing. Their manner of nesting 



