154 Bulletin Wisconsin Natural History Society [Vol. 13, No. 3 
Anas platyrhynchos Linnaeus. Mallard. 
An abundant species found most commonly in zones three 
and five: in the latter only in the spring, and if the swamp is 
well under water. Food consists mainly of aquatic plants 
plucked from the bottom in the shallow water. A few pair 
breed in the large swamp areas about the formation, and are 
attracted to the area apparently by the large water-cress beds 
about the mouth of the first spring. 
Anas rubripes Brewster. Black duck. 
A fairly common species, found often in company with the 
mallards, and more frequently in zone five than three. Prob- 
ably not a nesting species within the area. 
Mareca americana (Gmelin). Baldpate. 
Common in zones two and three, and occasionally in five. 
Found also in the ponds, which, as has been pointed out, are 
comparable to zone three of the lake. 
Nettion carolinense (Gmelin). Green-winged Teal. 
Found almost entirely in zones three and five, and most fre- 
quently in the former. Not a diving species, and therefore con- 
fined to the shallows for food. 
Querquedula discors (Linnaeus). Blue-winged Teal. 
Similar to the preceding species in general distribution, but 
a little more inclined to the lake than to the swamp. Was found 
as late as June 8, so that it is possible that it breeds within the 
formation. 
Spatula clypeata (Linnaeus). Shoveller. 
Never very common on Lake Wingra, but found within the 
confines of zones two or three, and usually in small flocks. 
Dafila acuta (Linnaeus). Pintail. 
Common in zones one, two, and three, and on one occasion 
found in zone five. March 14 is the earliest date of its occur- 
rence on Lake Wingra, then in company with mallards and 
canvasbacks. 
Marila americana (Eyton). Redhead. 
Not as common about Lake Wingra as the following species, 
and when found is confined to zones one and two, and but rarely 
comes into three. Stomach-content examination of four individ- 
uals shows an average of 80% or more vegetable matter, 10% 
gravel, and 10% animal matter, as snails, small insects, and in- 
sect larvae. 
