ISSN 1067-4136, Russian Journal of Ecology, 2007, Vol. 38, No. 4, pp. 271–276. © Pleiades Publishing, Ltd., 2007.
Original Russian Text © A.A. Nikol’skii, 2007, published in Ekologiya, 2007, Vol. 38, No. 4, pp. 293–298.
The temperature environment (temperature niche)
of subterranean mammals has not yet been inade-
quately investigated. This is explained mainly by difﬁ-
culties related to direct measurements of temperature in
the depth of burrows. However, convective mixing of
the air within and beyond the burrow is insigniﬁcant,
and, therefore, heat transfer by convection from the air
at the ground surface to the depth of the burrow is lim-
ited (Nikol’skii and Khutorskoi, 2001; Nikol’skii and
Savchenko, 2002; Nikol’skii et al., 2005). Therefore, to
determine the temperature regime of burrows, it is actu-
ally sufﬁcient to describe the temperature regime of the
soil in which they are built. When entrances to the bur-
rows are closed, as is the case with mole rats, the tem-
perature in the burrow is absolutely dependent on soil
For this purpose, it proved to be expedient to use the
Handbook on the Climate of the Soviet Union
vochnik po klimatu SSSR
) published in the mid-1960s
to the early 1970s that provided relevant data for the
entire territory of the former Soviet Union. In particu-
lar, there are data on the monthly average soil tempera-
ture at depths of 20 cm to 320 cm measured by means
of pit thermometers under
herbaceous cover in
summer and snow cover in winter. It is known that most
mammalian species build their burrows within this soil
layer, 3–3.5 m deep.
This study is devoted to experience in applying data
on soil temperature to the description of the tempera-
ture niche of the greater mole rat
Güld. (1770), a typical representative of terrestrial
mammals. The term “temperature niche” is understood
here as the temperature environment realized by under-
ground mammals in a three dimensional space: (1) the
space of the species range; (2) soil depth to which the
burrows penetrate; (3) time (periods of the species life
cycle). These conditions provide the possibility of
temperature niche, which is
analogous to the fundamental ecological niche (Hutch-
inson, 1978) that, in contrast to the realized niche, char-
acterizes the entire species range.
Thus, the task was to study the whole variety of tem-
perature conditions under which the species lives,
throughout the species range, taking into account sea-
sonal changes in the temperature proﬁle of the inhab-
ited soil layer.
The greater mole rat populates the steppe and for-
est–steppe zones of Ukraine and the European part of
Russia between the Dnieper and Volga rivers, except for
the Lower Dnieper sands populated by
The northern boundary of its distribution passes at
N, the southern boundary is formed
by the coast of the Sea of Azov and Ciscaucasia at
N, extending to the Volga north of
Volgograd (Dukel’skaya, 1932; Migulin, 1938; Reshet-
nik, 1941; Ognev, 1947; Vinogradov and Gromov, 1952;
Topachevskii, 1969; Gromov and Erbaeva, 1995).
The burrows of the greater mole rat are usually
located at depths of 20 cm to 3 m, but different soil hori-
zons are utilized to different degrees, depending on the
season (Beme, 1931; Dukel’skaya, 1932; Migulin,
1938; Reshetnik, 1941; Ognev, 1947; Barabash-Niki-
forov, 1957; Topachevskii, 1969; Puzachenko and Vla-
sov, 1993). The ﬁrst tens of centimeters are occupied by
surface tunnels used by mole rats mainly for foraging.
The upper level of burrows is connected with the lower
level by steeply descending shafts (Dukel’skaya, 1932;
Migulin, 1938; Reshetnik, 1941; Ognev, 1947; Gulyae-
Temperature Niche of the Greater Mole Rat
A. A. Nikol’skii
Russian University of Peoples’ Friendship, Podol’skoe sh. 8/5, Moscow, 113093 Russia;
Received April 25, 2006
—With consideration of the data on soil temperature within the range and over the burrow depth of
the greater mole rat
Güld. (1770) published in the
Handbook on the Climate of the
, it has been shown that the fundamental temperature niche of this species is relatively narrow.
The seasonal activity of the greater mole rat in the vertical plane of the burrow depends on the vertical distri-
bution of soil temperature.
: greater mole rat, burrow, temperature niche.