2 SECRETS OF ANIMAL LIFE 



selves in all probability in a region which they 

 never before visited. Furthermore, as Bird Key is 

 the last piece of land between the coast of Florida 

 and the coast of Texas, the birds can be sent out to 

 sea for hundreds of miles beyond sight of all land- 

 marks. Between Bird Key and Galveston, for 

 instance, there is open water for 855 statute miles, 

 obviously a fine expanse for homing experiments. 



The technique of the experiments is as follows: 

 A bold, vigorous tern is caught, it is marked char- 

 acteristically with oil-paint on the head and neck; 

 two tags (small and large, but otherwise duplicate) 

 are prepared, recording the date, the place, and the 

 kind of marking; the small tag is tied round the 

 bird's neck; the large tag is fixed to a foot-long 

 stake pushed down into the sand near the nest if 

 the bird is a Sooty or tied to a convenient twig if 

 the bird is a Noddy; the bird is put into a large 

 hooded cage and transported to a distance on 

 board ship ; it is kept in good health with minnows 

 from the refrigerator; it is liberated at a chosen 

 point; and then its return to the nest is watched 

 for. The most important general result is that 

 these terns are able to return from Galveston, 

 more than 800 miles away, over a body of water 

 which apparently does not offer any basis for con- 

 trolling flight direction. Some returned in about 

 six days, some took nearly twelve, some did not 

 return at all. Many of the return journeys from 

 distances .greater than 500 miles did not require 

 more than three to five days, but sometimes as 



