286
CHARLES J. KREBS AND JUDITH H. MYERS
2 5 1
In
c
-c .- 0 2 0 -
n F
9 Z 0
e
0
L
- P ;-;- z
1 1 1 1 1
A M J J A S
I
I
I
I
1
1
1
1
1
I
I
I
I
I
J@l t\\\,\
- J--'\.,
\
\
\ \ '
\ \
5 -
I\\/
O
!
!
!
!
!
I
I
I
I
I
I
I
I
I
I
1965
1966
I
I
I I
I
I
9
b
- -
A M J
1967
FIG. 10. A population cycle of Microtw ochrogaater in southern Indiana. A Type
M decline occurred in the fall of 1966. (After Krebs et al., 1969.)
FIG. 11. A population cycle of Clethrionomye rufocanue in northern Finland.
A Type H decline occurred in 1956. (After Kalela, 1957.)