1915] 
Cahn: Ecology of Wingra Springs Region 
133 
to be infected with the parasite. In this pond then, hibernate 
some of the parasites that infest, if not kill eventually, 42 per 
cent, of the grasshoppers upon which many of our birds feed. 
III. CLIMATIC FEATURES 
As is the case in the greater portion of the state of Wisconsin, 
the climate in the region under consideration is severe, and is 
characterized by great variations in temperature, both daily 
Fig. 3. The Second Pond. 
and seasonal. The winters are usually long, and are marked 
by fluctuations of temperature resulting in a succession of more 
or less severe thaws and freezes. Few data are available as 
to the date of the freezing over of Lake Wingra; in 1913 it closed 
on November 2, and in 1914 on November 29. The inevitable 
result of the closing is the departure of the water birds, and as 
a result, the region is “dead” during the winter so far as they 
are concerned. The springs keep a small space of open water 
