126 Game Survey of the North Central States 



deposits, and most of them on the fresh glacial deposits left by the most recent 

 (Wisconsin) glaciation. In Ohio heavy populations of pheasants were found to 

 extend in "ribbons" along the glacial outwash streams into the unglaciated area 

 on the southern edge of the State, while few or no pheasants were found on the 

 immediately adjacent unglaciated soils. The recent more careful survey of Ohio 

 by Hicks and McCormick (unpublished) fully confirms these observations, in- 

 cluding the "ribbons." There are no thrifty pheasant populations beyond the 

 glacial boundary and the few birds found there may be accounted for as strag- 

 gling plants, and as drift from the glacial "ribbons." 



Upon surveying Wisconsin, however, a recent voluntary establishment of 

 Hungarians were found on unglaciated soil in Vernon County in the west central 

 part of the State. This colony evidently originates from recent plantings on the 

 adjacent unglaciated area of Minnesota. They have increased to 40 birds since 

 their arrival in 1928. If this voluntary establishment proves to be permanent, the 

 glaciation hypothesis must be dropped as untenable for Hungarians. It may, 

 however, ultimately fail in the same manner as colony establishments have been 

 known to fail in both species in the southern zone of failure. 



The boundaries of both fresh and old glacial deposits appear on both the 

 Hungarian and pheasant maps (Maps 10 and 11). With the exception of the 

 Wisconsin colony just described, all successes with Hungarians are within the 

 exterior boundary of the Wisconsin glacier. This is also true of the full and 

 conclusive establishments of pheasants, but some thin or indeterminate establish- 

 ments of pheasants occur on the older glacial deposits of central Illinois, or 

 northeast Iowa, and northwest Iowa. These older deposits are more or less 

 covered by wind-borne soils known as loess, and lie between the new deposits and 

 the unglaciated soils. It remains true, however, that no full establishment of 

 proven permanence of either species as yet occurs on the residual, or wholly un- 

 glaciated, soils of the north central region. 



Whether or no the glaciation hypothesis ultimately holds water, it is no 

 longer regarded as very important, except as a temporary rule-of-thumb for the 

 guidance of planting policy. It does not explain causes. It is possible that the 

 fresh glacial deposits contain lime or grit of a quantity or quality necessary to 

 the welfare of these birds. This possibility is supported by the fact that their 

 European range, in so far as I know, is likewise freshly glaciated. Beebe tells 

 me, however, that the pheasant range of China is not. (Letter, October 10, 1928.) 



It is also possible that the glacial soils support some plant or insect which 

 contains some vitamin or mineral substance necessary to the welfare of these 

 species. That the glacial soils support a flora often sharply different from im- 

 mediately adjacent unglaciated soils is well known. The specific identity of the 

 particular plant or insect necessary for these birds remains totally unknown. 



The underlying thought of the glaciation hypothesis can, in our present 

 state .of knowledge, be better expressed in the form of a general nutritional 

 hypothesis, to be now presented. 



