Biology_of_Mustelids_Vol_1.pdf

105.
TABLE 1.
Activity of ermine above the snow, as % of census days on
which tracks were observed.
Years Total no. of No. of census Percentage of census
census days days when days when tracks
tracks observed observed
1959-60 37 4 10 .a
1960-61 35 4 11.4
1961-62 44 6 13.6
1962-63 45 7 15.5
Total 161 21 13.0
dsys falls, while with rise in the temperature, it increases. The sharp
fluctuations in the average annual numbers of watar voles in the four winters,
(which are the staple diet of tha ermine, according to Novikov) were not
related to the steadily increasing activity of the ermine.
(a) % trapping of
watervoles
(b) Average monthly
temperature °c
(c) % of days when
ermine tracks
observed
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--z
o J
\ I
\ I
V
(a) (b) (c)
Fig.1.
sur£ace.
Relationship between temperature and activity of ermine on the snow
1, activity of the ermine.(% of days tracks observed); 2, average
monthly temperatu~e;
3, autumn-spring trapping of water voles as percentage.
[Percentage of ~ is not stated. - Ed.]