Bartsch, Summer Birds of the Oneota Valley. 51 



SUMMER BIRDS OF THE ONEOTA VALLEY. 



(JUNE, JULY, 1895.) 



BY PAUL BARTSOH. 



Paper read before the Third Congress of I. O. A. 



NATURE as if to show mankind what the conditions in that great fertile 

 region traversed by the glaciers in the ice age, scarred, planed and 

 covered by a morainic deposit, would have been ; left untouched a strip of land 

 extending over south-eastern Minnesota, western Wisconsin and north-eastern 

 Iowa — a region wild, romantic and beautiful, the dream of our landscape ar- 

 tist, the paradise of our naturalist. 



This region within our bounds is traversed in the northern portion by the 

 Oneota river and its tributaries — it is the avifauna of this tract that I wish to 

 consider in the present paper. 



As topographic environment is one of the prime factors in the distribution 

 of many of our birds, it will not be amiss to briefly consider this feature of our 

 chosen field. 



The Oneota, though not as active as during glacial and preglacial time, is 

 nevertheless working slowly and diligently to lower its channel throughout 

 most of its course. The lessened amount of water causes the stream to meander 

 through a wide flood plane bounded everywhere by high ridges and bold bluffs. 

 One may get somewhat of an idea of the amount of work accomplished by the 

 stream in course of time, if he considers that it has cut a gorge through the 

 various formations from the Trenton down to about 300 feet below the summit 

 of the St. Croix sandstone. 



The little tributaries have been equally busy and even now seem to try 

 hard to cut down through the opposing rocks to keep on the same level with 

 the river. Not always able to accomplish this in a uniform manner, owing to 

 differences of rock texture, many beautiful water falls and cataracts have been 

 formed in their course. Not unfrequently the gorge cut by some small rivulet 

 has intersected an underlying water vein* and the additional force has helped to 

 grind and cut deeper the lower course of the stream and now a beautiful water 

 fall tumbles noisily from the chff. 



Throughout the course steep hills bound the valley on both sides. Fre- 

 quently perpendicular cliffs rise almost from the water's edge to a heighth of 

 several hundred feet and where the Oneota lime stone comes to the surface, 

 bold, bared, massive battlements crown the summit of the adjacent hills. 



The valley is wide, — the floodplane constitutes the farming land of the 

 region. The currant varies with the formation ; at places it is slack, then again 



* I particularly have in mind Seevers spring, some two miles south-east of 

 Decorah. 



