1913 ] 
Cahn: Birds of Waukesha County 
119 
decreasing. Formerly bred at Pewaukee Lake, according to 
Kumlien and Hollister, 4 but this was many years ago, and it is 
very doubtful indeed if at present any breed within the county 
limits. 
Marila valisineria (Wilson). Canvas-Back 
A common migrant, which seems just now almost, if not quite > 
to be holding its own against the hunters, although of course greatly 
decreased in numbers as compared with the flocks of former days. 
More common than the Redheads, with which migrant they may 
sometimes be found associated. Most common during the fall 
migration, particularly during November, when comparatively 
large flocks, often as many as fifty or more may be found. 
Marila marila (Linnaeus). Scaup Duck 
An uncommon migrant, though probably more common than 
the data at hand signify. A hunter was seen at Oconomowoc 
on October 20, 1913, with five good specimens of this species, . shot 
on Nagawicka Lake. Outside of three other specimens seen by 
the writer, data are lacking, as hunters do not distinguish between 
this species and the next, the common Bluebill. 
Marila affinis (Eyton). Lesser Scaup 
By all odds the most abundant of our ducks. Arriving about 
the middle of October, these ducks are abundant until driven 
south by the closing of the lakes. During early November, 1913,. 
hundreds of “Bluebills” were killed on Okauchee Lake alone. 
Yet, despite the great slaughter they undergo, they return year 
after year in apparently undiminished numbers. May be found on 
any of the lakes irrespective of size, and very often small flocks 
or lone individuals occur on the rivers and creeks. 
Marila collaris (Donovan). Ring-Neck Duck 
A common migrant, found most often associated with the flocks 
of Lesser Scaup ducks, in which they mingle. More common, 
however, on the larger lakes, and rare on the rivers. 
Clangula clangula americana Bonaparte. American Golden-Eye 
A common migrant, more abundant during the fall migration 
than in the .spring. One of the last ducks to arrive, remaining 
4 Birds of Wisconsin , p. 21. 
