The Behavior of Noddy and Sooty Terns. 191 



On account of the wide distribution of these two species of birds, of 

 their great numbers, and of their habit of assembHng; on islands during their 

 nesting season, frequent incidental reference to them is to be found in the 

 writings of naturalists. Saunders gives a fairly complete reference to this 

 literature. 



E.xtended statements concerning the instincts and habits of these birds are 

 not extant. Dr. Thompson^ gives the most comprehensive statement con- 

 cerning their habits. His observations, like my own, were made upon Bird 

 Key. The statements in his paper arc apparently made upon the basis of 

 intermittent visits to the island and are not always trustworthy. This is not 

 to be wondered at when we consider the complexity of the life of the birds 

 and the limited time which was at Dr. Thompson's disposal. 



Descriptive and none too exact statements of the nesting behavior of the 

 birds may be found in Henshaw- and in Rothschild.^ In the latter, most 

 of the observations were made by the naturalist Palmer. The work of 

 Walter K. Fisher^ is especially worthy of mention. 



The above references bear only in a general way upon my own studies. 

 In many cases, the observations to be found in them do not agree with my 

 own. I am not able to account for these discrepancies. The account of the 

 instincts and habits of these birds given here is made largely upon the basis 

 of my own observations.^ 



Xearly all of the statements concerning the habits of these birds, like my 

 own, refer to the nesting season. So far as I know to the contrary, almost 

 nothing is known of their life outside of this period. Many of the reactions 

 during the nesting season could be understood more easily if we knew the 

 complete history of their life-cycle. 



GEOGRAPHICAL SITUATION AND HISTORY OF THE PRESENT COLONY 



OF TERNS. 



Bird Key is a small coral island about 300 yards wide (east and west) by 

 400 yards long (north and south). It is 65.8 statute miles due west from Key 

 \\^est. The island is partially sheltered on the east and on the northeast 

 by a coral reef (fig. i). Northeast of the island, about 1.125 statute miles 

 distant, stands Fort Jefferson, now practically deserted. Still farther to the 

 northeast other low coral islands are to be found. Loggerhead Key lies 



' Bird Lore, vol. v, 1903, p. 77 ff. 



" Birds of the Hawaiian Islands, etc., 1902. 



'O/'. cit. 



' Birds of Laysan and the Leeward Islands, Hawaiian Group. Bull. U. S. Fish 

 Commission, vol. xxiii, 1903, pp. 767-807. 



"As e.xamples of differences in observations I cite the following: One writer 

 speaks of seeing these terns " swimming in the water.'' During my three months' 

 stay I never saw one of these birds in the water, except by accident ( see fig. 26, 

 plate id), and then the bird, if the tide is against it, can never reach the shore, so 

 poorly does it swim. Another statement is to the effect that these birds are often 

 seen flying at night at great distances from the shore. My own observation is to 

 the effect that the birds return, to the island at night and leave it at daylight. 



