Taste 1.—Statistics on the efficiency of capturing pheasants by nightlighting during prehunting season (October and early No- 
vember) and posthunting season (principally January) periods on the intensively farmed, 23,200-acre Sibley Area in Ford and 
McLean counties of east-central Illinois, 1956-1962. 
Capture Period Pheasant Density Number of Capture: Flush Ratio* Average Capture 
and (Birds per Pheasants (Percentage Time (Minutes 
Year Square Mile) Captured Captured) per Bird) 
Autumn or 
Prehunt 
1956 150 267 ay! 7.0 
1957 145 220 47 7.4 
1958 295 354 50 4.8 
1959 210 183 53 5.4 
1960 285 18] 40 5.3 
1961 370 369 et droll 
Total or Mean 1,574 46 a) 
Winter or 
Posthunt 
1957 60 189 36 8.5 
1958 110 127 42 10.0 
1959 95 177 16 5.0 
1960 110 182 40 oa 
1961 150 187 38 6.0 
1962 (160) + 260 37 No data 
Total or Mean U2, SH 6.8 
*Efforts were made to include only the initial flush of pheasants; repeat flushes were ignored because they were a product of capture 
attempts. 
+Estimate. 
tExcludes 1962. 
dance increased. In winter there was little relationship 
between capture time and population abundance be- 
cause the birds were usually concentrated in fields of- 
fering roosting cover. 
Mortality attributable to the nightlighting operation 
totalled 1.7 percent of 2,696 pheasants captured and 
processed (weighed, measured, and marked). The ma- 
jority of this mortality occurred during the time that 
the pheasants were held in burlap bags prior to proc- 
essing. Such losses were mitigated if only one or two 
pheasants were placed in each burlap bag, if cocks and 
hens were held separately, if the pheasants were held 
no longer than | hour prior to processing, and if the 
bags containing the captured birds were kept outdoors. 
Prairie Chickens 
Efforts to capture prairie chickens by nightlighting 
were restricted to a single colony of birds located on 
a 10,000-acre tract of agricultural land in south-central 
Illinois. This colony numbered about 300, 200, and 
150 prairie chickens in the autumns of 1962, 1963, and 
1964, respectively. In autumn these birds were found 
roosting, usually in small groups, in as many as 20 
different fields of small-grain stubble or tame hay. 
Prairie chickens were much less susceptible to cap- 
ture by nightlighting than were pheasants. Only 57, 
or about 17 percent, of 327 prairie chickens that were 
initially observed (repeat flushes not included) while 
nightlighting during the late summer and early fall 
periods of 1962-1964 were captured (Fig. 6). The cap- 
ture efficiency was about 19 percent in August (17 of 
88 birds) , nearly 28 percent in September (28 of 101 
birds) , and only about 9 percent in October (12 of 
138 birds). Young birds were more easily captured 
than adults in August and early September, but had 
gained the wariness of adults by October. 
The techniques for nightlighting prairie chickens 
were essentially the same as those used in capturing 
pheasants. However, the entire tempo of the operation, 
after observation of the bird, had to be accelerated to 
effect capture. Even with experienced nightlighting 
personnel, the capture of prairie chickens was not as- 
sured. 
Prairie chickens were almost impossible to capture 
by nightlighting on clear and/or moonlit nights. Under 
these conditions the spotlight was completely ineffec- 
tive in “knocking down” prairie chickens that flushed. 
The flushed birds usually flew out of sight before 
alighting, which prevented subsequent capture at- 
tempts. 
Cloudy, cool, and damp nights in early autumn were 
the best for capturing prairie chickens. To illustrate, 
on one night in mid-September, 1963, 21 (55 percent) 
of 38 prairie chickens that were flushed were captured 
—9 were adults and 12 were juveniles. This particular 
night was characterized by the arrival of a low-pressure 
weather front. It was very dark, due to a heavy cloud 
layer; mildly wet, due to a persistent mist; and cool 
(about 45° F.) . The success in capturing prairie chick- 
ens on this night was convincing evidence that they 
could be effectively captured by nightlighting under 
proper nighttime conditions. 
: 
4 
5 
