30 HOMING AND RELATED ACTIVITIES OF BIRDS. 



and then in the Antarctic region. Their track over the 11,000 miles separating 

 these regions is known to no one. Scattered individuals have been noticed 

 along the United States coast south to Long Island, but naturalists have never 

 observed these birds during migration, nor can they construct accurately the 

 routes of the birds from the records in hand. This means that the birds prob- 

 ably choose an ocean route and that their flight is almost continuous. 



Several interesting points bearing upon the problem of homing come out 

 from these studies of Cooke and others : first, that the plover and the Arctic 

 tern have no hesitancy in undertaking ocean routes several thousand miles in 

 length which can offer few if any landmarks in the ordinary acceptation of that 

 term; secondly, that the birds must fly by night, which again lessens the proba- 

 bility that landmarks of a visual kind are used. 



HOMING IN THE FRIGATE BIRD. 



In regard to the homing ability of the frigate bird, the following interesting 

 observation is cited from the Zoological Society Bulletin No. 29, p. 421. The 

 article is unsigned, but was written (so Dr. Chapman informs me) by Dr. 

 Charles H. Townsend. 



In the course of a winter's voyage on the 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 1,000 miles in a north- 

 west 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. 



I did not observe tame frigate birds elsewhere in Polynesia, but Mr. Louis Becke, who is 

 familiar with most of the South Sea Islands, says they were used as letter carriers on the 

 Samoan Islands, when there in 1882, carrying messages between islands 60 to 80 miles 

 apart. When he lived on Nanomaga, one of these islands, he exchanged two tame frigate 

 birds with a trader living on Nuitao, 60 miles distant, for a tame pair reared on that island. 

 The four birds at liberty frequently passed from one island to the other, on their own 

 account, all going together on visits to each other's homes, where they were fed by the 

 natives on their old perches. Mr. Becke's pair usually returned to him within 24 to 36 

 hours. He tested the speed of the "frigate" by sending one of his birds by vessel to Nuitao, 

 where it was liberated with a message at 4 h 30 m p. m. Before 6 o'clock of the same day the 

 bird was back on its own perch at Nanomaga, accompanied by two of the Nuitao birds, 

 which, not being at their perch on that island when it was liberated, it had evidently picked 

 up en route. 



Sixty miles in 1 \ hours is probably easy enough for the frigate bird, as in Malayo-Polynesia 

 it is said to have frequently returned a distance of 60 miles in one hour. It becomes entirety 

 tame and familiar when raised from the nest, and if given liberty returns regularly to its 

 home-perch at night. The largest rookery of frigate birds I have seen is at Tokokoto, in 

 the Low Archipelago. 



Frigate birds inhabit the tropical and subtropical seas. The spread of wing is phenomenal 

 for the size of the bird, being about 8 feet, giving wing-power perhaps unequaled. 



On page 48 our own experiments on homing in the frigate bird will be 

 considered. 



