September, 1943 
published a map with figures, credited to 
the National Fur Tax Committee, indi- 
cating that the “number of trappers” in 
Illinois was 132,990, but these numbers 
were perhaps misquoted and are certainly 
erroneous. Calculations for the seasons 
reported here set the average annual num- 
ber of trappers at about 256 per county, 
an average of slightly less than 1 to each 
2 square miles. “The number was exceeded 
considerably in the season of 1929-30, 
when the average per county was about 
340, and it was exceeded also in the 1930- 
31, 1937-38, 1938-39 and 1939-40 sea- 
sons. Ihe numbers are, of course, greatest 
in those counties where trapping is most 
profitable or where such game-fur animals 
as coons and foxes provide extensive sport. 
COMPARISON OF DATA 
The Brown & Yeager study was de- 
signed in part to obtain a check on the 
accuracy and usefulness of data based on 
fur-takers’ monthly reports, which were 
being used for studying (1) trends in the 
Illinois furbearer catch over a period of 
years and (2) distribution patterns of fur- 
bearers. When the 10 counties were se- 
lected as sampling grounds representing 
widely varying conditions in widely scat- 
tered regions in Illinois (fig. 2 of the 
Brown & Yeager report), it was known 
that the resulting figures would not coin- 
cide with those from the  fur-takers’ 
monthly reports, but the probability of 
similarities was recognized. We wished 
to find the nature and extent of both 
similarities and differences. 
Trends in Furbearer Catch.—For 
making annual comparisons between fig- 
ures from the oral survey and those from 
the fur-takers’ monthly reports, two meth- 
ods of working up raw data from the 
monthly reports were attempted. The first 
method involved, for each important fur- 
bearer, a calculation by counties of (1) 
the percentage of fur-takers who, on the 
monthly report blanks, reported catching 
that fur-bearer and (2) the reported aver- 
age catch per effective fur-taker* of that 
furbearer ; these figures were then weight- 
*As used in this report, the term effective fur-taker refers 
to a person who, in the season or seasons under considera- 
tion, has caught at least one individual of the furbearing 
species being discussed. Thus, a fur-taker who in a given 
year has caught muskrats but no other fur species is re- 
garded in that year as effective for muskrats only, 
Mour: FuRBEARER DISTRIBUTION AND INCOME 511 
ed according to the relative size of the 
counties. 
The second method, which was finally 
rejected, involved a calculation for the 
state as a whole of the percentages and 
averages mentioned in the first method; 
no weighting was done. 
Weighted data derived from the first 
method were less subject to local law 
enforcement irregularities than were data 
from the second, and they corresponded 
closely with figures calculated from data 
accumulated for the Brown & Yeager 
report. 
Data from this first method, such as 
that contained in table 2 and similar 
tables, can therefore be used as index 
figures by which changes in effective fur- 
takers and catch can be measured over 
a period of years. These figures, hereafter 
usually referred to as monthly report index 
figures, are believed to be the most useful 
obtainable to indicate trends over a period 
of several years, because up to the season 
of 1938-39 it had not been possible to 
trace by any other means the changes in 
numbers of fur-takers in the several parts 
of Illinois. 
The monthly report index figures show 
the greatest deviation from figures derived 
from the oral survey in the case of musk- 
rats. For the 1938-39 season, the differ- 
ence was 7 points and during the follow- 
ing season it was 10 points. Figures for 
most of the other furbearers deviated only 
4+ points or less. We believe that the 
deviation is not so great as to invalidate 
general conclusions about the average an- 
nual catch, or fluctuations in the catch 
from year to year. 
Numerical differences between the data 
derived from the oral survey and those 
from fur-takers’ monthly reports are to 
be expected. It is probable that the rela- 
tively small number of fur-takers repre- 
sented by the monthly reports, table 1 
and fig. 2, is selective and therefore not 
representative of the whole group. It is 
plain, too, that weighting the data from 
the monthly reports by area does not 
weight them according to the total num- 
ber of trappers, which would be a better 
weighting factor if it could be obtained. 
The monthly report figures represent 
several seasons, include trappers in every 
county in the state, and of necessity take 
into account only those trappers who ac- 
