September, 1943 Monr: 
center of relative scarcity lies in the south- 
eastern quarter of the state. 
About nine times as many minks were 
caught in Lake County as in Mason 
County, in 1938-39 and 1939-40, accord- 
0.9 : —e nthe et, 2 ods tees 2.8 
: O\e ele ® oe ® {nt 
aenat 
0.8 os) gies 
: oS eee 
e 
eoete 
® be 
at 
ee 
° 
Fig. 6.—Distribution of minks in Illinois as 
indicated by fur-takers’ monthly reports for 
the seasons of 1929-30, 1930-31 and 1934-35 
through 1939-40. Data for these eight seasons 
of monthly reports have been transferred to 
the map in such a way that the county having 
the largest average catch per fur-taker has 
the greatest density of dots; other counties are 
dotted proportionally. The numbers in the 
Margins represent for each county indicated 
the average catch per square mile as revealed 
by Brown’s survey for the 1938-39 and 1939-40 
seasons. In general, a close correlation exists 
between the two sets of data, despite the fact 
that one is for eight seasons and the other for 
two. 
ing to Brown’s survey. It is probable that 
some of the counties in the southeastern 
quarter of the state had even fewer minks 
than did Mason County, fig. 6. 
Trappers, Catch and Income.—The 
index figures for percentage of fur-takers 
catching minks, table 3, vary from 65 and 
62 during the 1936-37 and 1930-31 sea- 
FURBEARER DISTRIBUTION AND INCOME 
515 
sons, respectively, down to 43 in 1941-42, 
indicating a general population decline. 
The index figures are 5 and 6 points 
higher for the 1938-39 and 1939-40 sea- 
sons, respectively, than the percentages 
calculated on the basis of the oral survey 
data. Monthly report data show no change 
for the two seasons in the percentage of 
fur-takers catching minks, but oral report 
data indicate a rise in the second season. 
The  catch-per-effective-trapper index 
figures show no definite general trend for 
the 10 years for which we have data; the 
highest figure is 3.6 and the lowest 2.8, 
table 3. Index figures are 1.0 and 0.3 
point lower for the 1938-39 and 1939-40 
seasons, respectively, than the average 
catch figures derived from data accumu- 
lated by the oral survey for these seasons. 
Monthly report and oral report data indi- 
cate a drop for the second season. 
If these correlations, or differences, be- 
tween the oral survey figures and month- 
ly report indices held approximately con- 
stant back through 1929-30, then we may 
assume that about 12,400 fur-takers caught 
minks annually; the numbers were 15,600 
and 17,800 during the 1929-30 and 1930- 
31 seasons, respectively, and 14,197 cal- 
culated for 1939-40 from data obtained 
and assembled by Brown. Also, we may 
assume, the total annual catch by these 
mink hunters and trappers was 72,000 
and 87,000 during the 1929-30 and 1930- 
31 seasons, respectively, and 45,254 for 
1939-40, as recorded in table 11 of the 
Brown & Yeager report, with an annual 
average of 56,000. Income from minks 
is assumed to have averaged about $310,- 
000 annually. Averages are for the seasons 
of this study ending with 1939-40. 
The above figures mean an average of 
about 1 mink trapper to each 4 square 
miles, or roughly 121 per county; about 
1 mink caught per square mile, or roughly 
560 per county; $5.50 worth of minks per 
square mile, or $3,100 per county. 
A general decline in mink populations 
is indicated, the per cent of fur-takers who 
caught minks, and the number of success- 
ful mink trappers as well, having fallen 
noticeably in 10 years. The fact that the 
average-catch-per-effective-fur-taker indi- 
ces show no consistent decrease suggests 
that the decline is due to actual disappear- 
ance of minks over wide areas rather than 
mere thinning of standing populations. 
