Observations on the Summer Birds of Parts of Clinton 

 and Potter Counties, Pa 



BY FRANCIS E. COPE, .IK 



The chief value of such observations as Mr. Stewardson 

 Brown and myself were able to make during our recent trip 

 through certain sections of Clinton and Potter Counties, Penn- 

 sylvania, June 21-28, 1900, lies largely in the additional data 

 which they may furnish regarding the geographical distribu- 

 tion of the birds of our State during the breeding season, and 

 the reasons for such distribution. In a short paper of mine 

 published in the Proceedings of the Academy of Natural 

 Sciences of Philadelphia for 1898, I tried to show that, while 

 the avifauna of Susquehanna County was doubtless originally 

 composed largely of the Canadian element, it was now gradually 

 changing, the northern birds giving way to species which must 

 be considered typical of the AUeghanian and even of the Caro- 

 linian f.aunas. Furthermore, it seemed to me that this change 

 was largely caused by the cutting away of the original primeval 

 forest and thereby destroying the favorite breeding haunts of 

 many of our northern birds. 



Now these conclusions were not new. They were in the 

 main, I think I may fairly say, those already reached by Mr. 

 Stone in his observations regarding the "Summer birds of Har- 

 vey's Lake, Luzerne County, Pa." in 1891 (Proc. Acad, of Nat. 

 Sci. Phila., 1891, pp. 431-438), by Dr. Dwight in his study of 

 the "Summer Birds of the Crest of the Pennsylvania AUe- 

 ghenies," in 1892 (Auk, April, 1892), and by Mr. Baily in his 

 paper on the "Summer Birds of Northern Elk County, Pa.," 

 pubUshed during 1896 (Auk, Oct., 1896). And they have 

 been further confirmed by the more recent observations of Mr. 

 Stone and the Messrs. Behr on North Mt, Pa. (See the "Ab- 



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