32 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



evidence of breeding has been found, but it undoubtedly does breed. 

 In Tennessee, Wetmore (1939) lias found the bird in mountainous 

 country at 3,000 feet. 



The question naturally arises, Did Swainson's warbler always in- 

 habit higher altitudes, or is this a recent extension of range and partial 

 change of habitat? The answer will probably never be found; but 

 study of changing conditions in its low country habitat for the past 

 several decades may throw light on this interesting problem. Within 

 the writer's experience the canebrake areas have long been exposed to 

 forest fires, timber cutting, overgrazing, drainage, and the construc- 

 tion of a hydroelectric project, as a result of which thousands of acres 

 of timbered swampland are now under water. 



Spring. — The birds that winter in Jamaica enter the United States 

 through Florida, but it is probable that those from Yucatan make a 

 direct flight across the Gulf to the delta of the Mississippi. The 

 earliest recorded spring arrival in the United States was on March 22, 

 1890, on the lower Suwanee River. The same year the species was 

 taken at the Tortugas, March 25 to April 5 (Chapman, 1907). The 

 earliest arrival near New Orleans, was March 30, 1905 (Kopman, 

 1915). Meanley (MS.) records it from central Georgia on March 31, 

 1944. Swainson's warbler reaches tho, vicinity of Charleston, S. C, 

 during the first week of April, the earliest being the fifth of that month. 



Nesting. — ^Nests are built in bushes, canes, masses of vines, and 

 briers ; 10 feet seems to be the maximum height from the ground, while 

 some nests have been found as low as 2 feet. The average elevation 

 would be around 3 feet. As many nests are built over dry ground as 

 over water. The nest is quite bulky and loosely constructed ; a typical 

 one in situ looks like a bunch of leaves lodged in a bush or cane, as 

 the stems point upward. The outer walls of the nest are composed of 

 various leaves such as oak, gum, maple, tupelo, and cane; the inner 

 walls are usually of cane, while the lining is of pine needles, black 

 fiber of moss (Tillandsia), cypress leaves, rootlets, or grass stems. 

 Sometimes horsehair is also present. 



[Author's Note : A few more notes on the nesting of Swainson's 

 warbler may well be added to the above general statements. Brewster's 

 (1885b) nests, taken by Wayne in the lov; country of South Carolina, 

 are evidently typical for that region. All four of these nests were in 

 canes. Wayne ( 1886) says that the nests "are generally built in canes," 

 but he has also found them "in small bushes, and in one instance in a 

 climbing vine, by the side of a large public road." Brewster (1885b) 

 gives the measurements of two of his nests ; the smallest of the four 

 measures — 



externally 3.50 in diameter by 3.00 in depth ; internally 1.50 in diameter by 1.50 

 in depth; the greatest thickness of the rim or outer wall being 1.00. * * * 



