1067-4136/03/3402- $25.00 © 2003
Russian Journal of Ecology, Vol. 34, No. 2, 2003, pp. 122–126. Translated from Ekologiya, No. 2, 2003, pp. 134–139.
Original Russian Text Copyright © 2003 by Il’in, Smirnov, Yanyaeva.
Analysis of the present-day distribution of some for-
est (by origin) bat species shows that the western parts
of the ranges of
Linnaeus 1758 non Schreber 1775,
Schreber 1774 are character-
ized by some negative features (Strelkov, 1997). For the
last two species, Central Europe is now at the western
limit of their distribution. In particular, the numbers of
bats in Great Britain and the Netherlands
have decreased since the mid-20th century, and their
reproduction is no longer recorded in Bavaria and west-
ern Switzerland. This is explained by recent anthropo-
genic degradation of the range of these species in Cen-
tral Europe (Strelkov, 1997). Hence, their main breed-
ing area is now located east of the western border of the
former Soviet Union.
The purpose of this study was to estimate the effect
of economic activity on bats in the Volga region.
MATERIAL AND METHODS
Field studies were performed in the middle and
lower Volga region (55
1976 and 2001. The study area covered all natural
zones of the region, from desert in the Caspian Lowland
in the south to broadleaved forests in the north. On the
whole, we found 640 summer shelters of 14 bat species:
Keyserling, Blasius 1839,
Schreber 1774, and
non Schreber 1775.
There were 326 natural and 314 artiﬁcial shelters.
Artiﬁcial tunnels were distinguished as a special cate-
gory. With respect to structure and microclimate, they
are similar to natural caves, and both these types of
underground shelters are rarely used by bats in summer.
Hence, neither tunnels nor crevices in bluffs and rock
outcrops were taken into account in calculations. On
the whole, we found 42 various underground shelters
inhabited by bats. Table 1 shows data on the ﬁndings of
bats in different types of shelters.
The scheme of the main types of vegetation in the
Russian Plain (Lavrenko and Sochava, 1950) was used
as a basis for determining the natural zonal pattern of
the region. When treating and analyzing experimental
material, we operated on the following premises. From
north to south, as the climate becomes more arid and
the types of landscape change, the number of ﬁndings
of the forest bat species in the region decreases
(Strelkov and Il’in, 1990). Hence, the ratio between the
parameters of their occurrence in natural and artiﬁcial
shelters must regularly change in the same direction. To
analyze the use of shelters by these bats under different
landscape conditions more thoroughly, we have chosen
a transect running along the 53rd parallel of north lati-
tude, which marks the southern boundary of large broa-
dleaved–coniferous forests (this is especially evident
on the right bank of the Volga). South of this transect,
forest stands occur only in river valleys (forest strips)
and on some elevations (forest islands).
The preference of bats for different types of shelters
was estimated using both absolute and relative parame-
ters. The relative parameter (frequency) was calculated
as the percent ratio between the number of ﬁndings of
each bat species in different shelters and the total num-
ber of shelters found to the north and to the south of the
Effects of the Anthropogenic Factor on Bats (Chiroptera:
Vespertilionidae) in the Volga Region
V. Yu. Il’in, D. G. Smirnov, and N. M. Yanyaeva
Penza State Pedagogical University, ul. Lermontova 37, Penza, 440602 Russia
Received June 4, 2001
—Using the example of bats inhabiting the Volga region, the cases in which the anthropogenic factor
creates favorable conditions for these animals or signiﬁcantly reduces their diversity of their fauna are consid-
ered. In this context, an opinion concerning the approaches to the conservation of bats is formulated.
: bats, Volga region, summer shelters, anthropogenic factor, conservation of bats.