Biology_of_Mustelids_Vol_1.pdf

104.
INFLUENCE OF TEMPERATURE ON THE ACTIVITY OF THE
ERMINE
IN WINTER
By
V.A.
Kraft
Zool. zhurnal 1966, 45 (1)
148-150.
The material for this work was collected in the flood-plain of
the River Ishim, near the town of Tselinograd, over four winters (1959-63,
from 11
November to February).
We
used the method of counting the inter-
sections between tracks of the predator [and the route of the observer]
(Novikov 1953).
The standard transect was 7 km
(3 hrs) and the counts were
made 2-7 days after a fall of n~w
shown in Table 1.
snow.
The results of the counts are
As can be seen, the ermines spend most of their time under the
snow;
days.
on average, they were active on the surface on 13% of the census
When on the surface of the snow, each ermine keeps to a specific
hunting area, which rarely overlap.
In the winters of 1959-61, seven
ermine lived on one plot(a), and in 1962-63, six.
According to the records of the Tselinograd Observatory, the
climatic conditions in these four seasons differed.
the average winter temperatures over these years;
There was a rise in
the snow cover was
deepest in 1959-60 and in 1961-62, and considerably less in 1960-61.
From comparison between the data on (a) temperature and the
numbers of water voles in the four winters and (b) the percentage of days
on which the ermine were active on the snow surface (see Fig.1), it is
clear that in the seasons with reduced temperatures, the percentage ofective
(a) The word could rafer to length or area, but in this context probably
means the number of residant ermine along the standard transect. -
Ed.