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J Sherman, Carolinian Avifauna in Northeastern Iowa 



CAROLINIAN AVIFAUNA IX NORTHEASTERN IOWA. 



nv ALTHEA i(. SHERMAN. 



The map of the life zones of North America show i that a north- 

 ward projection of the Upper Austral Zone extends up the Mis- 

 sissippi River to latitude II degrees. The northern boundary of 

 this inn row strip very nearly coincides with that of the so called 

 "driftless area," embracing ;i territory of 10,000 square miles, which 



geologists (ell us was an island in the sea of ice during (lie glacial 



epoch; thai through it the Mississippi Riser flows in the old chan- 

 nel «nt by its waters ages before the glaciers came. Here and there, 

 cut out by erosion of wind and water, still stand vast piles of rocks, 

 often of picturesque forms with their ancient pinnacles and barti- 

 zans, saved by their insular situation from the grinding forces of 

 the ice. Thus near the river was left a rugged country over which 

 travel IS laborious; portions of the woodlands remain in their 



original wildness in which some of the solitude seeking species 

 of birds still find a home. It is a territory in which ornithological 

 i. 'arch has Keen very slight, the workers being too few to make 

 a general survey, yet for future reference notes on the occurrence 

 of southern forms of bird life in this region may he of some value, 

 and it is the purpose of this article to give my note-hook record, 

 for ten years in this field. For the most part the field of observa- 

 tion lies a few miles on cither side of the forty-third parallel of lati- 

 tude, and extends hack a dozen miles or more from the Mississippi 

 River. As stated la-fore the land nearest the river is bluffy; the 

 bell of hardwood forest thai Originally covered it varied in width 



from five to ten miles, beyond which the country is rolling prairie. 



In addition to those species, which in the strictest classification 

 arc termed Carolinian, a few words may be in place concerning 



the abundance of lour species that in the Mississippi valley range 



a hundred miles or more beyond the northern boundary of tin- 

 Upper Austral Zone. Of these the King Rail, Ralltu elegans, and the 

 Florida Gallinule, Gallinula galeata, are occasionally met. In some 

 years the Grasshopper Sparrow, Ammodramus savannarum auitra- 



li.s, may he estimated as a tolerably common summer resident, 



