TOPOGRAPHY. i183 
its course and unwittingly reach a higher latitude than else- 
where. The river itself has, tor the most part, little of the 
character which entices swamp breeders to its shores. While 
water birds follow its course they do not tarry to breed 
there, but pass northward. 
On the north Lake Erie is a factor to be reckoned with. It 
acts as a balance between the extremes of cold in winter and 
heat in summer, thus maintaining a more even temperature 
at any time of year, preventing the sudden changes which 
are so dangerous to both plant and animal life. Its chilling 
spring influence holds vegetation back until time for it to 
come forth, and by its warm breath in fall it wards off early 
frosts. Recognizing this influence upon vegetation, we are 
prepared for the appearance of some of the more southern 
breeding birds along the shore of the lake, and for the pres- 
ence all winter of some of the northern species which erdi- 
narily winter much fartner south. 
It has already been stated that marshes scattered sparing- 
ly along the lake front, usually where streams enter the lake, 
afford breeding places for many species. The archipelago 
lying north of Sandusky also affords suitable summer homes 
for many species not found breeding elsewhere in the state. 
Wherever clay banks front the water Bank Swallows and 
Belted Kingfishers nest in numbers. 
CLIMATE. 
For a detailed discussion of the climatic conditions of 
Ohio the reader is referred to a paper on “Some Climatic 
Conditions of Ohio,” by Mr. Otto E. Jennings, in the Ohio 
Naturalist for January, 1903. It is sufficient to say here 
that the mean range of temperature, which is 49° F. in the 
north and 55° F. in the south, and the much greater depth 
of snowfall in the extreme north-eastern corner of the state, 
are the principal factors which exert any marked influence 
upon bird life. A number of species are not only more com- 
mon in the warmer southern counties, but several never 
reach even the middle of the state. Greater snowfall means 
covered food in winter, and consequently fewer birds during 
