15*2 Bulletin Wisconsin Natural History Society [Vol. 13, No. 3 
The order followed, as well as the nomenclature is that of the 
American Ornithologist Union Check list. 
Order PYGOPODES 
Colymbus auritus Linnaeus. Horned Grebe. 
A constant, though not a common inhabitant of zone two; 
necessarily a lake bird, it was found only in the lake, and, being 
but a fair diver, it was found only in the intermediate lake 
zone. Only one specimen was taken, and its food consisted 
of eight Notropis cayuga , and a small amount of plant remains. 
The species does not breed within the formation, and passes 
north from Lake Wingra about the middle of April. 
Podilymbus podiceps (Linnaeus). Pied-billed Grebe. 
An abundant and nearly constant inhabitant of zone two, 
together with the preceding species. Arrives as soon as the 
lake opens in the spring, and remains until it freezes in the fall. 
During the breeding season the birds enter zone three where 
they nest occasionally. The food consists of small minnows 
( Notropis cayuga and N heterodon). and occasionally small 
bluegills (Lepomis pallidus) , small aquatic insects, as Zaitha and 
Ranathra, and a considerable amount of plant material. 
Gavia immer (Brlinnich). Loon. 
In the early spring and late fall these birds are common in 
zone one, which they are not seen to leave except when on the 
wing, of course. Xot a breeding species. 
Order LONGIPENNES 
Larus argentatus Pontoppidan. Herring Gull. 
A species common over zones one to four inclusive, and oc- 
casionally over zones five and six. As in this locality, at least, 
its food is limited to fish so far as is known, the range is limited 
or bounded by the food factor. First seen about the time that 
the ice breaks in the spring, and a few may be found occasionally 
at nearly any time of the year. Not a breeding species within 
the formation. 
Larus delawarensis Ord. Ring-billed Gull. 
Of the same distribution and occurrence as the preced- 
ing species, though probably not quite as common at any 
time. 
