Bird -Life in Southern Illinois 



IV. Changes Which Have Taken Place in Half a Century 



By ROBERT RIDGW^AY 



THE unprejudiced inquirer will no doubt find it diflficult to reconcile the 

 opposite statements and conclusions of two writers in the July-August 

 (1914) number of Bird-Lore,* concerning the question of whether 

 our native birds are decreasing or not. 



Mr. Thayer maintains that there has been no material decrease, and 

 believes that those who think otherwise are deceived by "illusions of percep- 

 tion, of memory," etc. (to quote from Professor Miinsterberg's letter), while 

 Mr. Kinsey declares that they have decreased, and gives several reasons (very 

 real ones, too) therefor. Mr. Thayer's observations were made at Keene, New 

 Hampshire, a manufacturing town founded in 1735; while Mr. Kinsey's were 

 made at Lathrop, Missouri, in an agricultural region, settled very many years 

 later. The essential difference in local conditions of the two places of observa- 

 tion will, in my opinion, account for these opposite conclusions. In New Hamp- 

 shire, the major changes were doubtless made and a readjustment of the 

 'balance of nature' established long before Mr. Thayer was born; while in 

 Missouri, as in any more recently settled agricultural country, these changes 

 are continually going on, through steadily progressing deforestation, drainage, 

 and extension of cultivated areas. In other words, in the purely agricultural 

 districts, the area of woodland, swamp, and all uncultivated ground, is steadily 

 and rapidly growing less from year to year; and hence, in like ratio, there is a 

 constantly progressing restriction of areas suitable for shelter and nesting- 

 places for birds. The conditions in the older, mainly manufacturing or pastoral, 

 states, especially in New England, are quite different, inasmuch as such 

 changes in the country as have more recently taken place are rather favorable 

 to bird-life than otherwise, many fields having grown up to brushwood or young 

 forests, while long stretches of bare roadsides and denuded fence-lines are the 

 exception rather than the rule. Indeed the conspicuous difference between the 

 two sections of the country in this respect can hardly be realized except by 

 those who are familiar with both. 



It has not been my good fortune, as it has Mr. Thayer's, to visit annually 

 the scenes of my earlier observations. My visits have, however, been frequent 

 and it has recently been my privilege to spend eighteen consecutive months in 

 one of the two localities where the earlier observations were made;t and 

 altogether, these visits have enabled me to make a reasonably exact state- 



*Comparative Abundance of Birds: A letter from Abbxitt H. Thayer and Professor 

 Munsterberg's Letter (pp. 263, 264). — Why Birds are Decreasing. By Rolla Warren Kinsey 

 (pp. 26s, 266). 



tThe last winter, previous to that of I9i3-'i4, spent by me in Southern Illinois was in 

 iS66-'67; the last entire summer, that of 1866. 



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