V 
MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
Glen C. Sanderson and Helen C. Schultz, Editors 
Urbana, Illinois 
April, I 965 
Vol . 8, No. 4 
1. Pheasant Populations and Land Use $. l. Etter 
A total of I 37 dead embryos were found among fertile eggs in 57 of 214 suc- 
C r S ?n 4 1 P^ e ^ sant nests observed on the Sibley Study Area during the nesting seasons 
of 1962, 1963, and 1964. Although 37.0 percent of the hatched nests in 1964 contain- 
ed eggs with dead embryos, compared with 25-2 and 26.6 percent in 1962 and 1963 , 
respectively, this difference did not appear to be significant since the percentages 
of eggs containing dead embryos were essentially the same during the 3 years ( 7.2 
6 . 2 , and 6.9 percent in l 962 , I 963 , and 1964, respectively). 
The ages of the unhatched embryos varied from 2 to 23 days. Of these embryos, 
N 6 (84.7 percent) were from I 7 to 23 days of age and only 21 (15-3 percent) were 
rom to 6 days of age (Table 1). These data suggest that some embryo mortality 
m *Y e the resu1t °f some hens laying one or two eggs after incubation has begun, 
which do not hatch before the hen and hatched chicks leave the nest. 
Tabte j. Ages of embryos in unhatched eggs from successful nests, Sibley Study 
Area, 1962-64. Data are from 57 nests located on 100, 10-acre plots. 
Incubation Stage 
(Days) 
1962 
Number of 
1963 
Embryos 
1964 
Total 
Percent of Total 
1 - 8 
4 
6 
0 
10 
7-3 
9-16 
4 
7 
0 
1 1 
8.0 
17-23 
60 
39 
17 
1 16 
84.7 
Total 
68 
52 
17 
137 
100.0 
2. Manipu1 at ion of Pheasant Habitat 
G. B. Joselyn 
The initial test of a chemical defoliate (Ortho Diquat) on £ mile of roadside 
during September 1964 to determine its potential for use as a chemical seedbed 
preparative was described in Monthly Wildlife Research Letter, Vol. 7 , No. 10 
(October 1964). Chemical defoliates have been used for several years with consid¬ 
erable success in the western part of the United States for pasture renovation, 
where spraying with the chemicals (to kill the existing vegetation) and seeding are 
usua y combined in the same operation, the sprayer being attached to a specially 
designed sod seeder. Such chemical defoliates are considered to have great potentia 
in aiding the establishment of roadside seedings over broad areas with a minimum 
of time and expense. 
