Vol. 5, No. 4 
Page 5 
Reasonably good counts were obtained for the following speciess meadowlarks, 
dickcissels, red-winged blackbirds, bobolinks, horned larks, and grasshopper sparrows. 
Results of these counts are presented in table 4. 
Table 4.—Comparison of the number of selected species of birds observed per 
hour in treated and untreated hayfields during June and July, 1960 and 1961. 
Donovan 
Maple Grove 
Iroquois 
Beaverville 
Year of 
Treatment 
1960 
Year After 
Treatment 
1961 
Year of 
Treatment 
1960 
Year of 
Treatment 
1961 
Untreated 
1960 1961 
Hours of Observation 
15 
12 
15 
12 
15 
12 
Birds per Hour 
Prairie Horned Lark 
2.2 
2.3 
0.7 
3.7 
0.1 
4.7 
Bobolink 
11.6 
3.8 
14.6 
3.0 
3.0 
0.3 
Meadowlark 
2.0 
2.4 
1.2 
0.3 
9.0 
14.5 
Red-winged Blackbird 
7.1 
7.8 
11.6 
2.3 
20.0 
0.9 
Dickcissel 
12.1 
9.0 
12.6 
4.0 
25.7 
2.3 
Grasshopper Sparrow 
6.1 
3.2 
0.7 
6.4 
1.9 
5.8 
Total for All Species 
41.1 
29.0 
41.4 
20.2 
59.7 
23.5 
The summers after treatment more birds were observed per hour in untreated 
fields than in treated fields. The summer of 1960, after the Donovan and Maple 
Grove areas were treated, 41.1 and 41.4 birds were observed per hour, respectively, 
in treated fields. In comparison, 59.7 birds were observed per hour in the untreated 
Beaverville fields. After the Iroquois area fields were treated in 1961, only 20.2 
birds were observed per hour. Bird populations in the fields of the Donovan area 
appeared to be well on the way to recovery in 1961 when 29 birds were observed per 
hour in the Donovan fields compared with 28.5 birds observed per hour in the 
untreated fields. 
