100 
CHRISTMAS 
COUNT 
DATA 
80 
60 
10. 207-31. 1092208 30) 10 2205-31 men Be Z0 mel 10 20 28 10 20  SIss0see 
OCT NOV DEC JAN FEB MAR APR 
Fig. 14. — Illinois records for the northern shrike plotted by date. The asterisks represent the cumulative number of north 
shrikes seen for each 10-day (approximate) interval — October 1-10, 11-20, 21-31 — for the years 1880-1971 inclusive. The shac 
area represents data from the Christmas counts. 
NUMBERS OF NORTHERN SHRIKES REPORTED (1880-1971) 
%=Northern Shrike - Central 
ths 
3.0 
NORTHERN SHRIKE 
Fig. 15. — Annual variatior 
winter populations of the nortl 
2.0 and loggerhead shrikes, based 
Audubon Christmas counts in no 
ern and central Illinois. Graph | 
show the number of northern 
loggerhead shrikes seen per 
1.5 party hours in northern Illn 
Asterisks show northern shrike ] 
ulations in central Illinois for y 
when the species was recor 
Zero counts, i.e. most years, ' 
not plotted for the central reg! 
LOGGERHEAD 
SHRIKE 
: , 
| 
| 
0.5 | | 
| 
| 
SHRIKES COUNTED PER 100 PARTY HOURS 
1940 1945 1950 1955 1960 1965 1970 
16 
