The variation of the tail measurement is very great in the above 

 series, since nearly all of the specimens are of nesting birds, in which 

 the longer of the two long tail feathers are frequently frayed or 

 broken or even absent. 



The geographical range of the Yellow-billed Tropic-bird includes 

 the islands of the West Indies ; it extends as far west as Central 

 America, and north to the Bermudas. The following records 

 of its occurrence in the United States have also been reported: 

 One on the coast of Nova Scotia, September 4, 1870;^ one in the 

 interior of Nova Scotia after a violent storm, in September, 1870;^ 

 an immature specimen captured in Orleans Co., N. Y., 1879;^ 

 and one shot on the Banana River, Florida, April 21, 1886.^ 

 A few others have been reported off the coast of Cape Hatteras ^ 

 and the coast of Florida.^ Their occurrence in the United States 

 is rare, and none have been found to breed on our shores. 



The Tropic-birds migrate from the West Indies and, except for 

 occasional stragglers, none are to be found in the Bermudas during 

 the winter months. This annual migration flight is remarkable 

 when it is considered that the birds must necessarily fly over open 

 water for a distance of more than 600 miles without any landmark 

 to guide them. The first Tropic-birds appear at the Bermudas 

 during the latter part of February, according to fishermen and 

 local observers, but the great bulk of them do not arrive until the 

 first weeks of March. Mr. Mowbray, Superintendent of the 

 Bermuda Aquarium, while making a voyage to Turk's Island in 



I Reid, BuUetin U. S. Nat. Musemn, 1884, vol. 25, p. 264. 



! Gilpin, Orn. and Oo., 1882, vol. 7, p. 123. 



3 Coues, BuUetin, Nutt. Ornith. Club, 1880, vol. 5, p. 193. 



* Brewster, Auk, 1886, vol. 3, p. 481. 



fi Gault, Wilson Bulletin, 1902, vol. 9, p. 141. 



6 Lawrence, Pacific R. R. Reports, 18.58. 



