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Bulletin Wisconsin Natural History Society [Vol. 11, No. 4 
nest was found during the last week of March, 1913, with the female 
sitting, when the ground was covered by a late fall of snow. 
Gregarious at all times, and several nests have been found on a 
very few square yards of territory. 
Cyanocitta cristata cristata (Linnaeus). Blue Jay 
An abundant summer resident, and usually a winter resident 
as well; found practically everywhere. There is little complaint 
on account of the jay’s egg-eating habit, but the farmers shoot 
them constantly as much, perhaps, because of their constant noise 
as because of their reputation for grain eating. 
Corvus brachyrhynchos brachyrhynchos Brehm. Crow 
A common resident, increasing steadily in numbers. The birds 
nest in almost any grove of trees, from 8 or 10 feet to almost any 
attainable height. Will return to the same nesting site year after 
year, reconstructing the old nest. 
Dolichonyx oryzivorus (Linnaeus). Bobolink 
A common summer resident, breeding in suitable places, and 
becoming abundant during the fall migration. On August 5, 
1912, a flock of over four hundred settled in the marsh along the 
Oconomowoc River, where it remained for several days. The 
birds were all in nearly full winter plumage, despite the early date. 
Molothrus ater ater (Boddaert). Cowbird 
A very common summer resident. The cowbird’s ability to 
detect nests of species on which it can impose its eggs is truly 
remarkable. Four cowbird’s eggs were removed on four consecu- 
tive days from the nest of a song sparrow, concealed in the heart of 
a dense Barberry hedge. The chief victims of the cowbird’s 
imposition are the yellow warbler, redstart, song and field sparrows. 
Xanthocephalus xanthocephalus (Bonaparte). Yellow-Headed 
Blackbird 
A common summer resident and breeding species, but very 
local in distribution. A colony breeds regularly in the rushes at 
the north end of Nagawicka Lake and another, smaller colony, 
about Ashippun Lake. It is an open question why the breeding 
area of this bird is so restricted, when there are plenty of apparently 
equally attractive regions throughout the county. 
