812 REPORT OF STATE GEOLOGIST. 



two kinds of Screech Owls, one red, the other gray. The fact is, the 

 color is independent of age, sex or season. This double-color phase is 

 called dichromatism. 



In Indiana, in the Wabash Valley, 95 per cent, of the Screech Owls 

 have been found to be red (Eidgway). From the Miami Valley of Ohio 

 and the Whitewater in Indiana about 60 per cent, were found to be 

 red (Langdon, Jour. Gin. Soc. N. H., April, 1882, pp. 52-3). In the 

 winter of 1886-7, in Franklin County, Indiana, red Screech Owls were 

 abundant and gray ones exceedingly rare. Up to 1882 almost all 

 seen were gray, and prior to 1886 red Screech Owls were rare. At 

 Terre Haute and at Bloomington, Carroll County, red is the prevailing 

 phase. But it had not always been so. Prof. B. W. Evermann in 1890 

 said: "In 1877-'79 we got a good many Screech Owls at Camden, per- 

 haps twenty all told, and I think there were only four or five red ones. 

 Since 1885 I have seen four or five at Burlington, all red. In 

 Wabash County both the red and gray phases are abundant. Since 

 1886, at Terre Haute, I have seen perhaps fifteen or twenty, and only 

 three or four of them were gray. In 1891 Miss Bessie 0. Gushing 

 (Ridgely) secured three red Screech Owls at Peru." In Lake County, 

 in 1886, Mr. L. T. Meyer said the gray form predominated. Mr. E. M. 

 Hasbrou-k has given us the result of his studies of this problem (Amer- 

 ican Naturalist, Vol. XXXII, p. 521, etc., 1893), from which I make a 

 few notes: 



There are places where only the gray is known. There is at least 

 one place, from the neighborhood of the mouth of the Ohio River 

 southward to Louisiana, where only the red form prevails, while be- 

 tween the two areas are found both red and gray. The State of In- 

 diana is in this belt, and the greater part of it is in that portion where 

 the red form predominates. All records show that the offspring of a 

 pair of gray birds are invariably gray. On the contrary, the young of 

 a pair of red birds, or a pair of which one is of each color, red and 

 gray, may be part of one color and part of the other. 



To the mind of the author all this presents a nice little study in 

 evolution, in which he has discovered humidity, temperature, acquired 

 characters and forest area are important factors. Mr. Ridgway had 

 previously suggested humidity as one cause. (Proc., U. S. Nat. Mus., 

 1878, p. 108). 



Mr. John Wright, a relative, living in Bartholomew County, told 

 me in the summer of 1897 of some Owls that lived in or near a bridge 

 in that county that attacked a number of persons who attempted to 

 cross the bridge after night. They had attacked him. They were 

 small Owls, he said, and he thought they were this species. 



