BIRD ROOKERIES OF TORTUGAS BARTSCH. 491 



air to be upthrust on the windward side, and upon this column of air 

 the man-o'-war birds will poise themselves with such perfect balance 

 that they seem fixed to a certain spot in the sky. A hundred or 

 more birds at a time may be seen thus hanging motionless suspended 

 over the northeast portion of the fort, low down when the wind is 

 slight, and high up when strong, always in the place which suits their 

 powers of adjustment best. 



Their power of vision is likewise marvelous. I recall being at 

 work in a shallow stretch of water when a fish broke above the sur- 

 face, evidently pursued by a larger member of the finny tribe. A 

 brown pelican at once gave chase and almost reached him, as the fish 

 leaped from the water the third time in short intervals, but a man-o'- 

 war bird that had been suspended way up in the air so high as to 

 appear a mere speck, came down with a rush and snatched it almost 

 from the very beak of the pelican. I have many times since enjoyed 

 casting fish out into the water of Key West Harbor to watch the 

 speed with which man-o'-war birds, soaring high up in the air, will 

 notice them and stoop to pick them up without touching a feather or 

 missing a strike. Our plates 33, 34, and 35 show a series of pictures 

 giving different poses, responses to such baiting in Key West Harbor, 

 while plate 36 shows the man-o'-war birds on Bird Key. 



At times a superior-winged man-o'-war bird will give chase to a 

 less endoAved individual that has captured a fish and worry him until 

 he disgorges it. The pursuing bird will quickly follow the falling 

 fish and snatch it before it reaches the water. The gulls and boobies 

 are similarly parasitized by the man-o'-war. 



Dr. Charles H. Townsend, the director of the New York Aquarium, 

 gives an interesting brief account on the homing of the man-o'-war 

 bird, from which the following quotation is taken: 



In the course of a winter's voyage on the IT. S. S. Albatross in the South 

 Seas, the writer found among the natives of the Low Archipelago many tame 

 frigate birds. The latter were observed on horizontal perches near the houses, 

 and were supposed to be merely the pets of the children who fed them. 



They were entirely tame, having been reared in captivity from the nest. As 

 our acquaintance with the people developed, we discovered that the birds were 

 used by them after the manner of homing " pigeons " to carry messages among 

 the islands. 



The numerous islands of the Low Archipelago extend for more than, a thou- 

 sand miles in a northwest and southeast direction, and it appears that the 

 birds return promptly when liberated from quite distant islands. They are 

 distributed by being put aboard small vessels trading among the islands. The 

 birds are liberated whenever there is news to be carried, returning to their 

 perches sometimes in an hour or less from islands just below the horizon and 

 out of sight of the home base. Generally they are in no great hurry. As the 

 food of the frigate bird may be picked up almost anywhere at sea, there is no 

 means of ascertaining how much time the bird loses in feeding or trying to 

 feed en route. It may also linger to enjoy its liberty with other frigate birds. 



