THE 



WILSON BULLETIN 



NO. 72-73. 



A QUARTERLY JOURNAL OF ORNITHOLOGY 



VOL. XXII SEPTEMBER - DECEMBER, 1910. NO. 3-4 



OLD SERIES VOL. XXII. NEW SERIES VOL. XVII. 



AT THE SIGN OF THE NORTHERN FLICKER. 



INTRODUCTION. 



The studies upon which this paper is based were conducted 

 at National. Iowa, which is situated in the north-eastern part 

 of CHnton county, a few miles inland and south-west from 

 McGregor. That it is an exceptionally favorable place for the 

 study of birds the readers of the Wilson Bulletin know from 

 the few short articles and notes b}- the author of this paper 

 w hich have appeared in the Bulletin from time to time. 



If we properly interpret the particular function of the Wil- 

 son Bulletin, this paper accurately typifies it. While there 

 is a certain value to the detection of slight differences in the 

 plumage of our North American birds from museum speci- 

 mens, and perhaps a necessity for giving names to groups 

 of idividuals showing the differences, it remains for the 

 careful student of the livng birds to detect the causes for 

 such variations. Of the two fields of study it must be clear to 

 all that the study of the living bird in its environment is much 



