496 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



in autumn, these birds rest here for a varying length of time before 

 continuing their travels. These migratory land birds always show 

 the effect of their stay on these keys, for most of them look entirely 

 different from the trim little creatures which we are accustomed to 

 see on the mainland. The little warblers and even the bobolinks 

 are all fluffed up and ragged and their appearance and motion sug- 

 gest " the dim gray dawn of the morning after," the after effect of a 

 " night out." They are lacking in shyness and appear quite as care- 

 less about their safety as they do about their appearance. 



The eagerness with which they take to a pan of fresh water or the 

 dripping of a leaky storage tank leads me to believe that it is the 

 want of fresh water that is responsible for this change of habit. 

 The only regular supply of fresh water that these birds can obtain 

 on any of the keys are the droplets of dew in the early morning 

 hours and that furnished by an occasional shower. This, then, 

 means a full drink and bath in the early morning and a long thirst 

 through the rest of the hot day. The bathing is rather an interest- 

 ing function under these circumstances. A bird will rest on a clump 

 of sparkling leaflets, beating his wings against them and thereby ac- 

 cumulating sufficient moisture in the course of time to become thor- 

 oughly washed. The vireos and flycatchers plunge against the moist 

 foliage, while the swallows merely graze it as they pass by. 



No small land birds breed upon the Tortugas, and it has been held 

 that the lack of fresh water is responsible for this. This explana- 

 tion alone does not appeal to me, for I know of no exposed fresh 

 water upon any of the keys between Miami and the Tortugas, and 

 yet most of them support several or more species of breeding land 

 birds. It seems more likely that the character of the vegetation and 

 its associated insect fauna is more to their liking on some of the other 

 keys, for the predominant floral element in the Tortugas is bay cedar, 

 a plant that forms a scarcely notable feature in the key flora farther 

 north. 



Believing that a list of all the birds so far reported from the Tor- 

 tugas will not be without interest to the reader, I will close this 

 article with it. 



In preparing this list I have consulted the registers in the division 

 of birds of the United States National Museum to see what speci- 

 mens the national collection contains from the Tortugas. Here I 

 found quite a large series of early records made between 1857 and 

 1864, which appear in the following list in the columns headed by 

 these numbers. 



The 1857 column represents birds collected by G. Wiirdemann 

 while connected with the Coast and Geodetic Survey. 



The 1859 column represents specimens collected by Capt. D. P. 

 Woodbury. 



