Ten Spring Bird Lists 187 



D. C. H. C. Oberholser, W. L. McAtee. Number of species seen, 96. 

 1909, May 10. About same route as in 1907. E. A. Preble, W. 

 L. McAtee. Number of species seen, 71, my own list only; my 

 notebook states that Preble saw 7 others. 



1912, May 9. Mouth of Four-mile Run to Munson Hill and 

 Upton, Va. A. K. Fisher, E. A. Preble, W. L. McAtee. Number 

 of species seen 85. 



1913, May 12. Elkins, Mouth of Difhcult Run, Mouth of Dead 

 Run, upper Turkey Run, Langley, and Chain Bridge, Va., and D. C, 

 by car to Foxhall Road, thence along Foundry Run to Observatory 

 Heights, D. C. E. A. Preble, W. L. McAtee. Number of species 

 seen 73. 



1917, May 17. Mt. Vernon, Dogue Creek, Little Hunting Creek 

 and Dyke, Va. Alex. Wetmore, W. L. McAtee. Number of species 

 seen 95. 



1918, May 11. Woodlawn, Dogue Creek, Dyke and New Alex- 

 andria, Va. Clarence Shoemaker. Alex Wetmore, W. L. McAtee. 

 Number of species seen 101. 



1919, May 13. Woodlawn, Dogue Creek, Little Hunting Creek 

 and Dyke, Va. A. K. Fisher, E. A. Preble. W. L. McAtee. Number 

 of species seen 100. 



1920, May 11. Same route as 1919. Alex. Wetmore, E. A. 

 Preble, W. L. McAtee. Number of species seen 98. 



1921, May 18. Woodlawn, Dogue Creek, Gum Spring, and 

 Dyke, Va. Remington Kellogg, E. A. Preble, W. L. McAtee. Num- 

 ber of species seen 88. 



Commenting- on tliese trips, it is at once apparent that 

 they are sliarply marlved off in two five-year gronj's. The 

 average number of species seen on tlie lirst five trips was 

 81.0 and on tlie second 96.4. Tlie explanation for this 

 striking divergence may well be stated at once, leaving 

 detailed comment to follow. It is that the excnrsions for 

 the first half of the decade were mainly np-river from 

 Washington, in less varied country, v^rhile the last five 

 were distinctly down-river, bringing the observers through 

 not only much territory like that up-stream, but also 

 along the broad expanses and more extensive marshes of 

 the lower river. Naturally, therefore, the most striking 

 difference in the character of the bird lists for the two 

 groups of trips is the greater prevalence of water-birds in 

 the second set. Down the Potomac seems a better place 

 to see also the marsh hawk, bald eagle, osprey, red-bellied 

 woodpecker, bobolink, yellow-throated warbler, mockingbird 

 and marsh wren, Tlie presence of the starling in none of 



