1915] 
Cahn: Ecology of Wingra Springs .Region 
153 
Larus Philadelphia (Ord.) Bonaparte's Gull. 
This species is present within the formation for but a very few 
days, but during those days it is abundant. Keeps strictly over 
the lake, feeding upon small fish, presumably Notropis cayuga. 
Sterna hirundo Linnaeus. Common Tern. 
A very common species in the spring, appearing in large 
flocks which haunt the lake zones, and occasionally excursion 
into the two swamp zones (five and six). Like the gulls, the 
terns are limited in their distribution by the food limitations. 
Feeds commonly upon Notropis cayuga or any species that can 
be caught within a few inches of the surface of the lake. Not 
a breeding species within the formation. 
Hydrochelidon nigra surinamensis (Gmelin). Black tern. 
Not a common species at any time, and one of much more 
limited distribution, being but rarely found ouside of zones one 
to three inclusive. A single pair nested on a deserted muskrat 
house near the springs region, but the nest was destroyed in 
some way. The food is essentially the same as that of the 
common tern. The species arrived somewhat later than the 
preceding one, the date being April 30 as compared with April 
19 for Sterna hirundo. 
Order STEGANOPODES 
Phalacrocorax carbo (Linnaeus). Cormorant. 
A rare bird in the Madison district, seen but once on Lake 
Wingra, and this time within the limits of the formation. Three 
individuals were present, and remained confined very closely 
to zone one. The birds were very wild. 
Order ANSERES 
Mergus americanus Cassin. Merganser. 
A common species, which, being a good diver, confines itself 
almost exclusively to zones one and two. 
Mergus serrator Linnaeus. Red-breasted Merganser. 
The commonest of the mergansers and, like the preceding 
species, confined to zones one and two. 
Lophodytes cucullatus (Linnaeus). Hooded Merganser. 
The least common of the mergansers found in the region, and 
similar in distribution to the other two. Is probably less active 
than either of the preceding, and seldom is found in flocks. 
