FAUNAL AREAS. 15 



Careful scrutiny of Dr. Wheaton's work will make appar- 

 ent to any one that there has been a very perceptible move- 

 ment of many species northward or north-eastward during 

 the last two decades. Several species known then to breed 

 near the lake shore clearly do not breed there now, or if 

 at all very rarely. Several species which did not reach the 

 lake shore then are regular breeders there now. Some spe- 

 cies which were confined to the southern border of the state 

 twenty years ago have now reached the central counties, 

 or pushed even farther north-eastward. Bewick Wren, at 

 least, has invaded the state from the south-west. There is 

 some indication of an invasion of the Blue Grosbeak and 

 Nonpareil soon. In winter, we in the north now have Rob- 

 ins and Bluebirds with us in small numbers, where seven 

 years ago none remained. The temperature is not chang- 

 ing, but the birds are gradually developing into hardier an- 

 imals. 



The species involved in this north-eastward movement 

 may be mentioned. Of the warblers: the Prothonotary,. 

 Worm-eating, Golden-winged, Chestnut-sided, Magnolia,. 

 Kentucky, and the Hooded. Besides these the Summer 

 Tanager; White-eyed Vireo ; Pine Siskin; Lark Sparrow; 

 Dickcissel ; Cardinal; Carolina Wren ; Bewick Wren; Tur- 

 key Vulture ; and Wilson Snipe. These are the species most 

 affected. It is more than likely that the whole bird host is 

 gradually shifting northward as the weaker ones perish, leav- 

 ing only the hardier individuals to occupy the arena of daily 

 strife for existence. 



FROM WHENCE BIRDS HAVE COME INTO OHIO. 



Birds seem to have appeared upon the earth during the 

 lower Jurassic or possibly even during the upper Triassic 

 times in the world's history. No fossil birds of these times 

 have been found in Ohio, yet it is not impossible that such 

 occurred in the region now named Ohio. However that 

 may be, it is certainly true that the great ice invasion from 

 the north, marking the close of the Tertiary Period and the 



