482 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



may be present. The number usually depends upon the size of the 

 harassed school of fish. 



As to the nocturnal activities of the birds, Watson states : 



From other observations, too numerous to mention separately, I conclude 

 that all birds return to the island at night. Many times just at sundown I 

 have come from Loggerhead Key to Bird Key. The terns are coming in by 

 hundreds and thousands, flying low over the water. By the time twilight has 

 faded the water is entirely deserted. Several trips made to Fort Jefferson 

 late at night showed that these birds do not leave the island at night. The 

 moment the island is reached, however, no matter at what hour of the night, 

 one finds the sooties busily flying from one place to another on it. 



An interesting pastime of the sooties is described by Watson. 



The sooties often soar round and round, getting higher and higher until lost 

 to sight. They usually join the frigate birds in this reaction. I am inclined 

 to think that the sooty when sufficiently fed spends a large part of its time in 

 such maneuvers. 



It will circle in the air again and again, giving out the shrill nasal alarm 

 cry of eah, eah, eah. It is the most restless and noisy bird I know, and almost 

 as much so at night as during the day. Sleep apparently is taken during both 

 day and night by dozing momentarily at intervals. How the bird maintains 

 its vigor with no more continuous rest than it takes is a mystery. This pe- 

 culiarity of the sooty has led to the popular nickname of " wide-awake tern." 



THE NODDY TERN (Anous stolidus). 



Here, as in the case of the sooty tern, we are indebted to Audubon 

 for the first account of this colony. I shall quote what he has to tell 

 us of his experience with these birds on the Tortugas in 1832. This 

 sketch is the more interesting on account of the fact that the birds no 

 longer breed upon the key (Bush Key) on which he found them nest- 

 ing, as all the vegetation, in fact, most everything shiftable above the 

 sea, has long since been swept away by the waves. His reference to 

 noddy nests on Bird Key mentioned in his sooty tern biography 

 shows that noddies had built nests in the bay cedars of that key, 

 although he states that they were not occupied at the time of his visit. 

 Since then the colony has been forced to make a complete shift and 

 the choice between Bird and Loggerhead Key has fallen to the 

 former, where Watson estimated the presence of 1,400 adult birds in 

 1908. We shall now quote from Audubon. 



About the beginning of May, the Noddies collect from all parts of the Gulf 

 of Mexico, and the coasts of Florida, for the purpose of returning to their 

 breeding places, on one of the Tortugas called Noddy Key. They nearly equal 

 in number the Sooty Terns, which also breed on an island a few miles distant. 

 The Noddies form regular nests of twigs and dry grass, which they place on 

 the bushes or low trees, but never on the ground. On visiting their island on 

 the 11th of May, 1S32, I was surprised to see that many of them were repair- 

 ing and augmenting nests that had remained through the winter, while others 

 were employed in constructing new ones, and some were already sitting on their 



