1915 ] 
Cahn: Ecology of Wingra Springs Region 
159 
one of which had eaten two swamp sparrows and showed traces 
of the hair of a small mammal; the other, one Microtus, and 
several large grasshoppers. 
Buteo borealis borealis (Gmelin). Red-tailed Hawk. 
A rare visitant which never spent more than a passing moment 
in the vicinity of the formation. 
Fig. 9. Nest and Eggs of the Marsh Hawk. 
Buteo lineatus lineatus (Gmelin). Red-shouldered Hawk. 
Not an uncommon visitor, found sailing over zones five or 
eight as a rule, but occasionally over zone seven. A male col- 
lected had eaten two toads, a garter snake, and a number of 
May beetles. 
Buteo platypterus (Vieillot). Broad-winged Hawk. 
Seen occasionally during the migrations in zones five and 
eight. The stomach of an adult male contained four young 
mice still unfurred. 
