ee | 
aca . Son 1 
0.01; = Se 
| Ba Green-winged Teal SQ 
O De E SS Sa — 
/ H SNe NS LK ‘ 
| | / MAA QQ vr 
0.35 4 / / 1938 liunting Season 
j 
| / nate 
o / Blue- SS 
oi I ie eiaeea . 
; Teal ‘ 
O.1 / 
| es 
| —_— ze Set 2. 
oe of Water 
ety 
| 
| 
: 
: 
: 
per 
iS 
is 
eae 
a 0.2 | 
uy 
a 
O Dicey RADIO eee ot 
G 
(e) 
se 3 
2 | 
5 DUCK CENSUS 
2 r ILLINOIS RIVER 
(o) 1938 
0 | 
u sO ee | 
oO q 
> } 
<q 
@) ‘ea a ates aan Gas i pac ain aa a sais ll ee 
Boo 
Mallard 
tw 
oO 
iD 
(@} 
——-——- 
| 
Aug Sep Oct | Nov Dee 
The duck populations represented in the above polygons were 
measured as follows: the ducks were counted on numerous lakes 
throughout the concentration area. The acreage of each lake censused 
was then measured on large scale mans with a planimeter. The points 
on the polygons show the number of ducks per acre of water during 
weekly periods. A moving average of three weeks was used to smooth 
the curve. 
