14 BIRDS OF OHIO. 
the period of snow. The rapacious birds, especially, go 
where food is more easily obtainable during the winter 
months. 
FAUNAL AREAS. 
“By far the largest part of the State is strictly Carolinian 
in its faunal characters; a small portion, the north-eastern 
corner, is as emphatically Alleghenian.” (Wheaton.) Dr. 
C. Hart Merriam, in “Life Zones and Crop Zones, of the 
United States,” 1898, shows clearly the extent of this arm 
of the Alleghenian fauna, so far as plant life is affected. I 
have attempted to indicate this area on the accompanying 
map. Topographically there seems to be nothing which 
indicates this difference. It is possible that the influence 
of the strictly Alleghenian region flows over into Ohio to 
that extent without any attendant local conditions of topog- 
raphy. A strong hint of the reason for it fies in the much 
greater snowfall over a large part of this Alleghenian area. 
The fact that the Hooded Warbler, Worm-eating Warbler, 
Kentucky Warbler, Golden-winged Warbler, White-eyed 
Vireo and Summer Tanager invade this area to breed, sev- 
eral of them reaching the lake shore in Ashtabula county, 
and do not breed as far north anywhere else in the state, 
would seem to indicate that the conditions which so strongly 
affect plant life have little or no influence upon these birds. 
They belong in the Carolinian Fauna. 
In northern Ohio there seems a strong tendency toward 
the Transition Zone, and in the south a strongly typical 
Carolinian Fauna in the Upper Austral Zone. Thus the 
Bobolink breeds plentifully all over the northern third of the 
state, but is scarcely found in summer south of the 40th 
parallel. Wilson Thrush also breeds north but is absent 
in summer south. The Black and Common Terns are found 
only at the lake shore in summer, but the Carolina Wren 
and Cardinal nest sparingly, but in increasing numbers,. 
even to the lake shore. South of the 40th parallel, except 
in the extreme north-east, the Kentucky Warbler and Sum- 
mer Tanager spend the summer. 
