referred; and (4) deliberate distortions of fact, usually 

 exaggerations." 



More direct efforts to estimate the state-wide abun- 

 dance and distribution of pheasants were made by 

 personnel of the Illinois Department of Conservation; 

 these efforts involved winter sex ratios and spring counts 

 of cock calls (William L. Preno unpublished). Spring 

 counts of cock calls were obtained by recording the 

 number of individual cocks heard crowing per 2-minute 

 period at each of 20 stops located at 1-miIe intervals 

 along 20-mile standardized census routes: these census 

 routes were established through most of the range oc- 

 cupied by pheasants in Illinois. The counting of cock 

 calls was begun 40 minutes prior to sunrise and com- 

 pleted about 40 minutes after sunrise. Usually two 

 spring call counts were taken annually on each census 

 route between late April and late May; only the highest 

 of the two counts was used in calculating distribution 

 and abundance of pheasants along a route. The average 

 number of cocks recorded per stop along each route was 

 used as an index to the number of cocks in the area. 

 Factors influencing the validity of crowing counts have 

 been discussed in detail by Kimball (1949). who first 

 described the technicjue, Kozicky (1952), and Carney & 

 Petrides (1957). 



During the winter preceding the spring counts of 

 cock calls in Illinois, .sex ratios had been obtained from 

 roadside counts of pheasants. Efforts had been made to 

 obtain the sex ratio of a sample of at least 200 pheasants 

 as near as possible to each route where a spring count 

 of cock calls was to be taken. The number of hens in 

 each area at the onset of the breeding season was esti- 

 mated by multiplying the number of cocks, as deter- 

 mined by the call counts in spring, by the number of 

 hens per cock, as determined by the sex ratio obtained 

 during the preceding winter. 



In 1957 and 1958, information on the distribution 

 of pheasants in Illinois was obtained through data col- 

 lected by rural mail carriers. The rural mail carriers of 

 the state made six 5-day counts of pheasants along their 

 routes: in February of 1957, in January of 1958, and 

 in April and August of each of these years. The first 

 count included all 102 counties of the state. The re- 

 maining five counts were restricted to 76 coimties, which 

 included all the counties of the contiguous range. .A 

 map ]jreparcd by Greeley (1960:29) to show pheasant 

 populations of Illinois in April, 1958, was based on a 

 census by the rural mail carriers. 



Questionnaires (postcards), with letters of instruc- 

 tion, were used in all six censuses. For the Fust l\\c) 

 censuses they were mailed directly to individual mail 

 carriers listed by the Illinois Rural Letter Carriers Asso- 

 ciation and for the other foiu" censuses to postmasters at 

 all post offices having rural routes. In the last four 

 censuses, the postmaster distributed the postcard ques- 

 tionnaires and instructions to the local mail carriers. 

 The mail carriers were asked to report the counties and 

 Uiwnsliips in wliich their routes were located, the length 



of each route in miles, and the number of pheasants 

 (cocks, hens, chicks, and broods) obsersed along the 

 route on each of the 5 consecutive days specified in the 

 instructions submitted with questionnaires. If the route 

 of a mail carrier extended into two or more townships, 

 the reported data were divided equally among all the 

 townships listed on the questionnaire. The number of 

 miles driven and the number of pheasants seen during 

 the 5-day period were used to calculate the number of 

 pheasants observed per 100 miles of roadside obser\a- 

 tion in each township. Township imits were used to 

 map the distribution and abundance of phea.sants in 

 Illinois, figs. 2-8. The use of township units for map- 

 ping the range of pheasants has the advantage of 

 geographically refining the limits of distribution and 

 abundance to a greater extent than if units the size of 

 a county, or larger, are used. 



Investigators have recognized that there is sampling 

 error and bias in most data used in mapping distribu- 

 tion and abundance of pheasant populations. The data 

 on which the maps presented in this report are based 

 undoubtedly contain both error and bias, but field ob- 

 servations have tended to confirm the patterns of distri- 

 bution shown for Illinois — sometimes in remarkable 

 detail. 



EVALUATION OF COUNTS BY RURAL MAIL CARRIERS 



Rural mail carrier censuses of pheasants have been 

 employed in Nebraska. North Dakota. South Dakota. 

 Iowa, Missouri. Montana (Kimball <■/ al. 1956:2.'i7-9) . 

 Michigan (MacMullan 1960:56-62), and Indiana (re- 

 ported by William E. Ginn at Fourteenth Midwest 

 Wildlife Conference, Des Moines. Iowa. 1952). Biases 

 involved in censuses by rural mail carriei's have been 

 recognized by all investigators using these censuses, but 

 the data obtained by such censuses in most states have 

 been found vei^v useful for determining annual indices 

 to the abundance of pheasants and for showing pheasant 

 distribution patterns. 



Rural mail carriers in Illinois exhibited mtei-est and 

 participated enthusiastically in censusing pheasants. 

 Nearly three-fomths of the questionnaires distributed 

 to the carriers were returned, and most of the returned 

 t|iiestionnaires contained usable information, table 1. 

 In the percentage of questionnaires returned, there was 

 no significaiu ditlerence between those distributed di- 

 rectly to the carriei-s and those distributed to the carriers 

 via postmasters. 



Several variable factors influenced the counts of 

 pheasants by mail carriers: principally because the ef- 

 fects of each were difficult to measure, no allowance 

 was made for ilu-iu when the data were analyzed. 

 Among these factors were (1) differences in interest or 

 obser\ational skill of the indixidual carriers. (2"i ])lu- 

 mage differences between cock and hen pheasants, 



(3) behavioral differences between cocks and hens, 



(4) seasonal differences in the amounts of vegetative 

 growth, (5) differences in the amounts of snow cover 



4 



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