Vol. IV. Part 2 August 25. l«09 



PROCEEDINGS OF THE 



Nebraska Ornithologists' Union 



AN ANALYSIS OF NEBRASKA'S BIRD FAUNA 



BY ROBERT H. WOLCOTT 



The number of species and subspecies of birds known to have 

 occurred up to the present time within the limits of Nebraska is 

 406, which large number is due to its unusually favorable geo- 

 graphical location. The state lies on the border line between the 

 humid eastern faunal areas and the arid areas of the west, and is 

 frequented by forms characteristic of each. Its extent east and 

 west, and the difference in elevation between the two ends of the 

 state is sufficiently great that while the eastern end is in the Mis- 

 sissippi valley, and shares its faunal character, the northwest cor- 

 ner is fairly in the foothills of the Rocky mountains. Its latitude 

 and the extremes of its climate are such that many southern birds 

 reach its southern border in the summer, while the storms of win- 

 ter bring to it at that season a large number of northern visitors. 



It should be noted at the outset that in the meeting of eastern 

 and western subspecies of the same species in the state there is, of 

 course, no sharp line dividing them, but on the contrary a gradual 

 shading of the one into the other. Intermediate specimens occur 

 representing all shades of gradation between them. It may be 

 that only a few of the specimens taken at the eastern end of the 

 state represent the one, while only at the extreme west are found 

 specimens typical of the other. But throughout this discussion 

 the subspecies assigned to any region is that to which the major- 

 ity of specimens taken there approach most closely. 



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