THE BIRDS OF WISCONSIN. 
115 
variety, it appears to me, are diminishing in numbers every 
year. Ten years ago from the 10th to the 25th of May the 
woods seemed to be alive with them, and I have counted more 
than a dozen varieties in two hours' observation. Now half 
a day's search will not reveal half that number. This is also 
true of many of our insectivorous birds, the Baltimore oriole, 
phcebe, the vireos and most of the finches being exceptions." 
This is probably too true of some localities, and probably 
generally throughout the state to some extent, but there are 
still many localities where a dozen varieties of warblers can 
easily be identified, in good numbers, in even less than two 
hours. 
Dendroica dominica albilora BidQW. SYCAMORE WARBLER. 
A rare straggler to Wisconsin. Dr. Hoy obtained a single 
specimen at Racine, June 20, 1848. Taken but once by Thure 
Kumlien, in 1877, at. Lake Koshkonong, and once at some 
other localitv in southern Wisconsin at a very earlv date, 
1842-50. 
Dendroica virens (Gmch). BLACK-THROATED GREEN WARBLER. 
Migrant. As is the case with many of the warblers, this 
one occurs in varying numbers, being sometimes only fairly 
common, and again greatly abundant, either in spring or fall. 
Dr. Hoy wrote that a few nest with us, and Mr. Clark suspects 
that they breed in Dunn County, as he has found them during 
the summer months. Young just able to fly were taken in 
Jefferson County in July, 1868, and adults are frequently seen 
in summer as far south as Rock, Dane, and Jefferson Coun- 
ties. We have known several pairs to remain in the vicinity 
of Milton all summer but have never succeeded in finding a 
nest. 
Dendroica vigorsii (Aud.J. PLVE WARBLER. 
A fairly common summer resident in the pine regions. 
Migratory in the hardwood districts of southern Wisconsin. 
Much more common along Lake Michigan than in the 
interior. A rather early arrival in the spring, generally pre- 
ceding the majority of the warblers by several d^ys. Although 
we have never found the nest w r e have noted this bird at vari- 
ous northern points in June and July. Dr. Hoy gives it as 
breeding in the northern pine forests, and Mr. Nelson found 
it nesting in northeastern Illinois. 
