Vol. 9, No. 8 
Page 2 
In 1965, 52 nests (2.6 nests per acre) were located on seeded plots and 33 ( 1.7 
nests per acre) on managed control plots. Sixty-eight nests ( 3.8 nests per acre) 
occurred on seeded plots in 1964, compared with 38 nests ( 2.2 nests per acre) on 
managed control plots, while in 1963 there were 44 nests on seeded plots (2.9 
nests per acre) and 41 nests on managed control plots ( 2.7 nests per acre). 
Thus, nest density on seeded plots in 1 966 increased by 0-3 nest per acre 
over 1965, decreased 0.9 nest per acre from 1964, and was identical to the density 
in 1963* Nest density on managed control plots was the same in 1 966 as in 1965 
(1.7 nest per acre) but was below the densities of 1964 and 1963 . 
The 0.7 hatched nest per acre on seeded plots in 1 966 was the lowest density 
of hatched nests for the 4 years 1 963~ 66 , but was not materially below that of 
1965 and 1964, whereas the density of successful nests on managed control plots 
in 1966 (0.6 hatched nest per acre) was the highest for the 4 years. While in 
the 3 preceding years the density of successful nests on seeded plots has been 
approximately double that on managed control plots, this year there was little 
difference in the per acre production on the two types of plots. The relatively 
large number of hatched nests on managed control plots in 1966 was a result of 
a higher degree of success among established nests (32 percent) than occurred on 
seeded plots (23 percent). Managed control plots hatched 17, 13, and 24 percent 
of the nests established in 1963, 1964,and 1965, respectively, while seeded plots 
hatched 39 percent of established nests in 1963 , 20 percent in 1964, and 29 per¬ 
cent in 1 965 • There is no apparent explanation for the high degree of success 
of established nests on managed control plots in 1966 , except to suggest that the 
vegetative succession on these plots (which remained unmowed each of the 4 years 
until early August) has now produced more secure nesting cover than existed at 
the outset of the study and up until the current nesting season. It is also 
possible that similarly favorable vegetative changes relating to security of 
nesting habitat have not occurred on seeded plots. Analysis of vegetative samp] in 
carried out on seeded and on managed control plots over the past 4 years may revea 
the magnitude of the changes which have occurred. 
Table 2. Numbers of established and of successful pheasant nests and numbers of 
established and of successful nests per acre on seeded and on managed control 
roadside plots, Sibley Study Area, 1 963 - 66 . 
Number of 
Number of 
Number of 
Estab1ished 
Number of 
Successf 
u 1 
Established 
Nests 
Successful 
Nests per 
Year 
Acres 
Nests 
per Acre 
Nests 
Acre 
Seeded 
Cont rol 
Seeded Contro' 
1 Seeded Control 
Seeded Control 
Seeded 
Contro1 
1963 
15.4 
15-0 
44 41 
2.9 2.7 
17 7 
1.1 
0.5 
1964 
17-9 
17.7 
68 38 
3-8 2.2 
14 5 
0.8 
0.3 
1965 
19-8 
19-3 
52 33 
2.6 1.7 
15 8 
0.8 
0.4 
1906 
22.4 
21.8 
65 38 
2.9 1-7 
15 12 
0.7 
0.6 
- 
