1067-4136/02/3302- $27.00 © 2002
Russian Journal of Ecology, Vol. 33, No. 2, 2002, pp. 109–114. Translated from Ekologiya, No. 2, 2002, pp. 120–125.
Original Russian Text Copyright © 2002 by Nikol’skii, Savchenko.
The transition from high to low temperatures in the
summer–autumn cannot fail to affect the thermal con-
ditions of mammalian burrows; however, little is known
about the actual range of seasonal air temperature ﬂuc-
tuations in the underground shelters of animals and the
degree of their dependence on temperature changes
above the ground. These data are important for under-
standing the ecological adaptations of animals inhabit-
ing high and temperate latitudes, at which air tempera-
ture is subject to seasonal ﬂuctuations measured in doz-
ens of degrees.
Our previous paper (Nikol’skii and Khutorskoi,
2001) described the results of observations on air tem-
perature changes in several dozens of steppe marmot
burrows over a short period of time in late July. In this
paper, we discuss the results of observations on air tem-
perature changes in one burrow, but over a relatively
long period, from late July to mid October. This time of
the year is characterized by a considerable decrease of
air temperature in the ground layer and, simulta-
neously, by an abrupt change in animal activity: while
preparing for hibernation, marmots plug the entrances
to their burrows with earth, thus reducing the effect of
environmental factors on thermal conditions in the bur-
To understand how air temperature changes above
the ground affect air temperature in the burrow, we
compare the daily amplitudes and seasonal dynamics of
air temperature within and beyond the burrow.
MATERIAL AND METHODS
Observations were performed near the village of
Nesterivka (Velikoburlukskii district, Kharkov oblast,
Ukraine) from July 26 to October 14, 2000. Air temper-
ature was recorded in a nest burrow of the steppe mar-
Müll., 1776). Such burrows are
typical of the study region (Tokarskii, 1997). The bur-
row was on a hill slope (about
) of eastern exposure.
A well-formed passage descended to the burrow at an
. Its horizontal and vertical diameters at a
depth of approximately 20 cm were 27 and 19 cm,
respectively. Marmots lived in this burrow in late July,
when the temperature sensor had already been
installed, but, in August, they moved to the neighboring
Temperature was measured with an electronic ther-
mometer manufactured in Sweden (model 02113),
which had an internal sensor in the upper part of its case
mm) and an external sensor connected with a
3-m wire. The external sensor was ﬁxed to one end of a
corrugated plastic tube (16 mm in diameter and 100 cm
long), and a 150-cm wooden handle was inserted into
the opposite end. The memory device of the thermom-
eter recorded the minimal and maximal temperatures
with an accuracy of
; instrument error was less
The external sensor was kept in the burrow perma-
nently at a distance of 280 cm from the entrance and at
a depth of 128 cm from the ground surface. The ther-
mometer with the inner sensor was placed 10 cm away
from the burrow opening and covered with an air-per-
meable wooden screen.
Air temperature within and beyond the burrow was
recorded every other day (on some occasions, daily) at
8 a.m., noon, 4 p.m., and 8 p.m. for a total of 45 days.
The minimum and maximum temperatures were also
recorded in the period from 8 p.m. to 8 a.m. on the next
day (taken as the date of measurement) for a total of
76 days. The lowest and highest temperatures over 24 h
were regarded as the “absolute” minimum and maxi-
Air Temperature Changes in a Steppe Marmot Burrow
in the Summer–Autumn Period
A. A. Nikol’skii* and G. A. Savchenko**
* Peoples’ Friendship University, Podol’skoe sh. 8/5, Moscow, 113093 Russia
** Kharkov State University, pl. Svobody 4, Kharkov, 310077 Ukraine
Received April 12, 2001
—Observations of air temperature changes in a steppe marmot burrow were performed from late July to
mid-October. Until early September, temperature in the burrow remained relatively constant, but then it began to
decrease rapidly. This occurred after air temperature above the ground became equal to the temperature in the burrow.
Supposedly, it is in this particular period that marmots begin to plug the entrance to the burrow with earth, thus reduc-
ing heat exchange between the increasingly cold aboveground air and the air in the burrow.
: steppe marmot, burrow, temperature, summer–autumn period.