Vol. XXI, pp. 107-118 April 11, 1908 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



BIRD MIGRATION IN THE DISTRICT OF COLUMBIA. 



BY WELLS W. COOKE, 



Bureau of Biological Survey. 



The data on bird migration in the District contained in the 

 records of the Bureau of Biological Survey extend over a long 

 series of years. Before the Biological Survey was organized 

 Coues, Prentiss and Drexler collected assiduously during the 

 years 1858-1861 and have left notes on many hundred speci- 

 mens. Not many records accumulated during the next fifteen 

 years, but from the late seventies to the present time observa- 

 tions have been almost continuous. On the organization of the 

 Biological Survey, very full notes were obtained for the six years 

 1886-1891 and, with the aid of the local Audubon Society, for 

 the past six years. The region covered by the District of Colum- 

 bia is nominally the country within a radius of ten miles of the 

 Capitol, but this limit has been exceeded to include a few notes 

 from contiguous territory. 



It will be noticed that the records on fall migration are much 

 less full than for spring. Some common birds have surprisingly 

 few fall dates, e. g. Marsh Wren, Blue-gray Gnatcatcher, Yellow 

 Warbler, Kentucky Warbler, Hooded Warbler, Warbling Vireo, 

 Rough- winged Swallow, Cliff Swallow and Baltimore Oriole. 

 Any one having notes on the date of fall departure of any of 

 the above species, will confer a favor by sending them to the 

 Biological Survey. 



The three tables that follow contain the names of 293 species — 

 all at present known to have occurred in the District. This is 

 one more species than is contained in the 1902 list of District 

 birds; the additional species is the Lawrence Warbler obtained 

 by Mr. Osgood, May 12, 1907. 



15— Proc. Biol. Soc. Wash., Vol. XXI, 1908. (107) 



